British Birds - Sample Copy

British BirdsVolume 103 • Number 4 • April 2010

© British Birds 2010

206 Great Blue Heron on Scilly: new to Britain E. Ashley Fisher

213 Using stable isotopes to investigate the provenance of an Eagle Owlfound in Norfolk Andrew Kelly, Kevin Leighton and Jason Newton

223 The breeding population of Northern Wheatears at Clee Hill,Shropshire, 1998–2009 Dave Fulton

229 The decline of the Ring Ouzel in Britain Innes Sim, Chris Rollie, DavidArthur, Stuart Benn, Helen Booker, Vic Fairbrother, Mick Green, KenHutchinson, Sonja Ludwig, Mike Nicoll, Ian Poxton, Graham Rebecca,Leo Smith, Andrew Stanbury and Pete Wilson

Regular features

240 LettersEskimo Curlews Andy StoddartEagle Owls in Britain Norman ElkinsThe malar stripe Lars Svensson andKeith E. Vinicombe

243 NotesRed Kites playing catch? David FergusonApparent nesting association ofNorthern Goshawks and FirecrestsGeoff MawsonCommon Kestrel attempting topredate Hobby chicks at the nest Dean NicholsonCommon Ravens and Grey HeronsPeter DavisSpotted Flycatcher nestreconstructed for second clutch A. P. RadfordMonitoring Hawfinches – anotheroption J. M. S. Lewis

Hazards of man-made material tonesting Hawfinches N. J. Westwoodand M. Watson

248 ReviewsCollins Bird Guide 2nd editionHelm Dictionary of Scientific BirdNamesThe Status of Birds inNottinghamshireUp River: the song of the EskWild Skeins and Winter Skies Wildlife Photography MasterclassThe Sounds of Raptors and FalconsPeregrine Falcon Populations

253 News and commentAdrian Pitches

257 Recent reportsBarry Nightingale and Eric Dempsey

British Birds aims to: � provide a forum for contributions of interest to all birdwatchers in the Western

Palearctic; � publish material on behaviour, conservation, distribution, ecology, identification, movements,

status and taxonomy; � embrace new ideas and research; � maintain its position as the respected journal

of record; and � interpret good scientific research on birds for the interested non-scientist.TT-COC-002609

BB April 2010 editorial 18/3/10 11:37 Page 205

206 © British Birds 103 • April 2010 • 206–212

Great Blue Heron onScilly: new to BritainE. Ashley Fisher

Abstract A first-winter Great Blue Heron Ardea herodias was found at LowerMoors, St Mary’s, Isles of Scilly, on 7th December 2007, during a period ofsustained westerly winds that extended across the North Atlantic. Its arrivalcoincided with a deep depression, which moved along the eastern seaboard of theUSA bringing snowfall and freezing temperatures, conditions likely to initiate cold-weather movements in North America. The age, timing and circumstances of itsdiscovery all point to this being a wild bird that arrived without the benefit of shipassistance, and it has been accepted into Category A of the British List.

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The weather charts on 7th December2007 showed that, for the second con-secutive day, tightly packed isobars

were spanning the entire width of theAtlantic, and a quick scan of additional dataon my computer monitor revealed that thecontinuous flow of gale-force southwesterlieshad reached speeds gusting up to 110 kph!Surely there had to be a storm-drivenNearctic vagrant somewhere in Scilly? I kepttelling myself this as I spent the morning atwork, daydreaming about all manner of pos-sibilities. Since it was December, options ofwhat could realistically be expected to turnup in these conditions were fairly limited,although this belief is actually a direct con-tradiction of one of my ingrained Scillyedicts – expect the unexpected. I thought thatLaughing Gull Larus atricilla would do verynicely indeed, especially as I had missed outon finding one during the 2005 influx. Withthis in mind, I set out for Porthloo beach tocheck the gulls which feed over the wind-driven, hide-tide surf, but when I got therethe wind was just too strong and the tide toohigh. Within minutes, my bins were coveredin sea spray and my eyes full of sand! Ineeded calmer conditions and decided thatthe shelter provided by Lower Moors mightbe a more productive option – at least therewas a chance of a lingering Wilson’s SnipeGallinago delicata still being there.

It was about 2.00pm by the time Ireached the HildaQuick hide but thelight there was awful,bright sunlight wasstreaming in throughthe window andreflecting off the water.Scanning through mysalt-coated bins, Inoticed a ‘grey heron’almost entirelyobscured behind apatch of Juncus fartherback. Through the hazeI could just aboutmake out its leftshoulder and notedthat the carpal/mar-ginal coverts appeared

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Great Blue Heron on Scilly

to be chestnut! I blinked and looked again.Yes they were definitely chestnut! Mythoughts turned immediately to the possi-bility of Great Blue Heron Ardea herodias, aspecies I had seen previously in NorthAmerica and had routinely checked for sincemoving to Scilly some eight years earlier.Being familiar with Grey Herons A. cinerea atthis site, I was also struck by this bird’sslightly odd behaviour; it was just hunchedup and standing motionless behind the vege-tation, in an area I knew to be surrounded bydeep water and rarely frequented by GreyHerons, even at low water. The hairs on mynape stood up and I got a massive jolt ofadrenalin! My excitement was tempered byan equal measure of incredulity. I rang BobFlood, giving him an excited account of thefeatures I had seen – he knew exactly what Iwas thinking and set off in my direction fromPorth Hellick.

The bird remained motionless for whatseemed like an eternity before it suddenlymoved across a small opening and vanishedinto an adjacent patch of Phragmites.Although views were brief and the bird stilllargely silhouetted, I instinctively checked forthe rufous thigh feathering; but the light wasjust not good enough and I was able to seeonly that the thighs were dark – not white ason some Grey Herons – and that the feath-ering appeared noticeably longer. The bird’s

110. First-winter Great Blue Heron Ardea herodias, Lower Moors,St Mary’s, Isles of Scilly, December 2007.

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size and structure were, however, markedlydifferent from what I would have expected ofa Grey Heron. Even without direct compar-ison, it was noticeably larger than a GreyHeron, with a proportionately longer neckand longer legs. Incredulity aside, by now Iwas becoming convinced that it must be aGreat Blue Heron; it just had to be! I gaveBob a quick update and then sprinted roundto the ISBG hide.

The patch of Phragmites into which it haddisappeared was only about 6 m from theISBG hide, so I opened the slat just a crackfor fear of flushing it. From this side of thepool the light conditions were perfect. Slowly,the heron’s head and neck appeared.Although it was still partly hidden in thePhragmites, this was not like any Grey HeronI had seen before! Through the partially openslat, I could make out only the head andneck. The bill was large and two-toned,blackish on the upper mandible and yellowon the lower becoming slightly more orangedistally. Side-on, the culmen appeared almoststraight. The lower mandible ran parallel tothe culmen for about two-thirds of its lengthbefore noticeably curving upwards towardsthe tip, forming a prominent gonydeal angle.The neck sides were subtly mottled dull greyand there was a faint rufous tint increasing instrength towards the fore-neck. It alsoshowed rusty and grey-striped ‘epaulettes’ atthe bend of the wing. Abruptly, the heronwalked into full view and point-blank range,just 6 m away. I nearly had a coronary! It wasabsolutely stunning! I checked the thighs andthey were a beautiful chestnut/ rufous colour,as were the marginal coverts and the tips tothe lesser and median coverts. It also hadsome distinctly blue-tinged feathers on theotherwise dull grey mantle. It was an absoluteclassic juvenile Great Blue Heron! I triple-checked all the relevant identification fea-tures I could recall and all were consistentwith my initial identification.

At that point, I was acutely aware that, if itflew off, not only would I be the only observerto have seen it, but the only record, apartfrom my field notes, would be a few (initiallyrather poor) ‘digibinned’ images. Momentslater and to my great relief, Bob entered thehide and was the recipient of some rathercolourful language, interspersed with ‘it is, it

is, it is!’ Shortly afterwards, Will Wagstaffarrived and the news went out nationally,while I rang all the local birders, who, one byone, arrived in the hide with shocked lookson their faces. For the first half-hour or so, itwas almost comical as we sat there viewingthe heron through the narrow gap in the slats.As we gained confidence that it would notflush, we carefully opened them more fully.The bird seemed a little nervous, however,and moved out towards the island on thescrape. Now we all enjoyed excellent viewsand many superb photographs were taken byWill and Martin Goody.

After about 30 minutes, unprompted, itflew off towards Shooter’s Pool. Apart fromits obvious large size, the most notablefeature was its long legs and feet, clearly pro-jecting farther beyond the tail than in GreyHeron and strongly reminiscent of PurpleHeron A. purpurea. After a while it flewagain, this time in the company of two GreyHerons. The difference in size and structurewas marked; the Great Blue was clearly larger,broader-winged, had distinctly longer legsand showed a more prominent neck bulge. Itthen returned to Lower Moors, where itremained until dusk.

Overnight, weather conditions worsenedand gale-force winds were accompanied bytorrential rain. Despite this being weatherthat no bird would voluntarily depart in,there was no sign of the heron the followingmorning. Around 70 or more twitchersarrived in Scilly the next day, but an extensivesearch of likely sites, including Lower Moors,Porth Hellick Pool and the entire coastline ofSt Mary’s, failed to relocate the bird. Thesearch continued over the following days andextended to suitable sites on Tresco, but theGreat Blue Heron was not seen again.

Detailed descriptionGeneral appearanceAlthough the plumage was superficiallysimilar to Grey Heron, the most striking dif-ferences were the chestnut/rufous thighs,fringes to the carpal and marginal coverts,and tips to the lesser and median coverts.Structurally, it differed from Grey Heron,even without the benefit of direct compar-ison, appearing larger and (proportionately)longer-necked with a larger head and heavier

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British Birds 103 • April 2010 • 206–212


bill. The legs were also markedly longer andprojected well beyond the tail in flight,strongly reminiscent of Purple Heron.Indeed, the bird spent much of the first halfhour of observation wading in the deepestarea of the pool (an area not frequented byGrey Herons), occasionally with its ‘rear end’(primaries, tertials and tail) partially sub-merged. Direct comparison in flight withGrey Heron confirmed many of the abovesize and structural differences, with the birdappearing clearly larger and broader-wingedthan that species, and with a more prominent‘neck bulge’.

HeadForehead and crown, including sides ofcrown, largely blackish-grey, forming a cap;at times this appeared plain blackish,although the forehead was perhaps a shadepaler and not as solidly dark, with an ill-defined, pale greyish-white wedge in front ofthe eye. Some feathers of the forehead andcrown were often held erect, forming aragged crest. The head plumes were blackish-grey and relatively short, tapering to a mod-erate point along the nape. The ear-covertswere contrastingly greyish but not solidly so,

i.e. ‘hollow centred’, bordered below by a dis-tinct dark gape line. The lores showed anarrow, diamond-shaped area of pale, yel-lowish-green skin, framed above and belowby dark grey feathering. The chin, throat andthe rear part of the ear-coverts were white.

NeckThe neck appeared proportionately long andnoticeably longer than that of Grey Heron.Indeed, the ‘neck bulge’ was comparativelymore prominent in flight. On a cursory glanceit appeared brownish-grey on the sides, but oncloser inspection was neatly mottled dull greywith a subtle rusty tint, increasing in strengthtowards the fore-neck, which was otherwisewhitish, narrowly streaked grey. ‘Epaulettes’streaked rufous, grey and off-white.

UpperpartsMantle, scapulars, back, rump and uppertail-coverts dull grey. Several distinctly bluish-tinged feathers noted in the mantle, thesepresumably being newly replaced first-winterfeathers. Tail short, dull grey.

UnderpartsBreast and belly off-white, streaked grey.



111. First-winter Great Blue Heron Ardea herodias, Lower Moors, St Mary’s, Isles of Scilly,December 2007.

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Flanks dark grey, appearing noticeably darkerthan on Grey Heron. Thigh feathering at thetop of the tibia uniformly rufous, butappeared to be narrowly streaked whitishwhen viewed at close range through a tele-scope, and this area of feathering seemed to bemore extensive along the tibia than on GreyHeron. Vent and undertail-coverts dull white.

UpperwingMarginal and carpal coverts conspicuouslychestnut, the latter with some white. Lessercoverts dull grey, the lower row clearly tippedrufous. Median coverts similar but withbroader, rufous, drop-shaped tips andwhitish terminal spots. Greater covertsbroadly similar, though at times appearedpaler, and had very narrow greyish-whitefringes, broadening slightly at the tips, with adiffuse rufous tinge subterminally. Tertialsdull grey, narrowly fringed paler greyish-white, and noticeably worn at the tips.Primaries and secondaries blackish-grey.

UnderwingSeen very well on numerous occasions as thewings were often raised and flapped when itwas adjusting its balance to counteract thefrequent gusts of wind. Lesser and medianunderwing-coverts blackish-grey, althoughsome rufous was noted on the lesser primarycoverts in photographs, but not noted in thefield, contrasting noticeably with palergreater underwing-coverts.

Bare partsThe bill looked larger, heavier and less evenlytapered than in Grey Heron. Side-on, theculmen appeared almost straight, with thelower mandible running parallel to this forabout two-thirds of its length before notice-ably curving upwards towards the tip,forming a prominent gonydeal angle. Theupper mandible was almost entirely black,except for a dull, dirty orange cutting edge.The lower mandible was pale greenish-yellowbecoming distinctly more orange distally. Irisyellow. Legs two-toned; dull greenish-yellowwith a diffuse, dirty blackish-brown wash onthe outside of the knee and tarsus. Theylooked noticeably longer than the legs ofGrey Heron, even without direct comparisonand, consequently, the bird tended to fre-

quent the deeper areas of the scrape not usedby Grey Herons – indeed, water levels wereparticularly high at Lower Moors on 7thDecember.

WeatherAt the time of the heron’s discovery, strongwinds were coming straight across the NorthAtlantic, caused by a deep depression thatmoved northeast along the eastern seaboard ofthe USA on 3rd and 4th December, bringingwith it a very cold air mass to its rear. Thisstrong northwesterly airflow brought wide-spread precipitation, mostly as snow, and sub-zero temperatures to the northeastern states ofthe USA and eastern Canada – a classicweather pattern likely to initiate cold-weathermovements in North America.

A likely scenario would have seen theGreat Blue Heron moving ahead of this coldair mass on 4th December, which would havebrought it into the strong westerly airflowover the western Atlantic. Here it would haveinvoluntarily overtaken the cold fronts andthen moved into a much warmer airstreamwith very strong (and still strengthening)WSW winds that would then have led to arapid flight across the North Atlantic,arriving on Scilly on 6th. In this warm sector,surface wind speeds to the southwest ofBritain & Ireland were being reported as60–65 kph, with sustained winds reaching100 kph at an altitude of 1,000 m.

In these winds, it is likely that the GreatBlue Heron made an unassisted crossing ofthe North Atlantic in just under the two days,covering a distance of approximately 5,000km in this period, which would be entirelypossible if it was travelling at an average sus-tained speed of c. 100 kph.

Great Blue Heron in the WesternPalearcticAlthough this was the first Great Blue Heronto reach Britain, its arrival here had beenwidely predicted. In fact, there have been twoprevious records of the species reachingBritish waters, but both individuals were fedaboard a ship, which excludes them from theBritish List. One of these arrived on board aship that docked in Avonmouth inNovember 1968. After being taken into care,it was treated at the Rode Tropical Bird Park

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in Frome, Somerset, where it was placed inan open aviary from which it departed whenit had recovered, never to be seen again(King 1978). The second bird died at seawithin 250 km of the Isles of Scilly in May1982, well within the BOU recording limit,but unfortunately after eating fish providedby the crew (Casement 1995).

It seems perhaps surprising that such alarge and conspicuous species had not beendiscovered in Britain earlier, particularlywhen viewed in the context of 40 AmericanBitterns Botaurus lentiginosus (albeit onlyeight since 1950), six Green-backed HeronsButorides virescens and one Snowy EgretEgretta thula which have made the crossing.Perhaps Great Blue Heron is less able tosurvive the transatlantic crossing than itssmaller congeners? Although there is nomeans of establishing whether this is thecase, exhausted Great Blue Herons appear tomake temporary use of ships in mid Atlanticwhen the opportunity arises (e.g. King &Curber 1972, Casement 1995, Herroelen1995). One of the birds that made landfall inthe Azores in April 1984, and subsequentlydied, had anti-rust paint on its back, whilethree others that succumbed had grease ontheir feet (Le Grand 1986). So there is littledoubt that ship-assisted Great Blue Herons

do reach this side of the Atlantic.Although ship-assisted vagrancy is a com-

plication when considering records of thisspecies, there have now been records fromFrance, the Canary Islands and several fromthe Azores, which suggest that unassistedvagrants do reach the Western Palearctic. Inthe case of the St Mary’s bird, there was noevidence to suggest that it could have beenheld captive on a ship or fed during a voyage;if fact, the prevailing weather conditions sup-ported a rapid transatlantic crossing.

AzoresA minimum of 24 Great Blue Herons havereached the Azores since the first in 1984. Ofthese, the records from late March (1) andApril (9), and October–November (11) coin-cide with peak passage periods in spring andautumn in North America. Within theseperiods, there were two notable influxes,accounting for no fewer than 15 individuals,with eight arriving in April 1984 (Le Grand1986), and seven in October–November 2006(http://azores.seawatching.net/index.php?page=greatblue). There have also been singlerecords in June (1984), July (2008) and Sep-tember (2005)(http://azores.seawatching.net/index.php?page=rarebirddata&id=309#NotFirst).



112. First-winter Great Blue Heron Ardea herodias, Lower Moors, St Mary’s, Isles of Scilly,December 2007.

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Canary IslandsOne was found on Tenerife on 5th December1998 (Clarke 1999).

FranceThe first for Europe was an adult on Îled’Ouessant, Finistère, in April 1996 (Duboiset al. 1997).

RangeGreat Blue Heron is a widespread breedingbird in North America, with its northernlimit extending into southeast Alaska. AcrossCanada it breeds from northern BritishColumbia, east through the central Canadianprovinces to southern Ontario, southernQuebec and the Canadian maritimeprovinces including Nova Scotia. It breedswidely throughout the USA south to Florida,Texas and southern California, and souththrough Mexico and Central America toBelize and Guatemala. Resident populationsalso occur in Cuba and Jamaica, and it hasrecently bred in Bermuda where migrantsoccur regularly.

Northern birds are migratory, with dis-persing birds reaching Newfoundland, Canada,and Greenland. It winters to the south of thebreeding range, mostly to the south of Canadaand mid-west United States, with some birdsreaching the islands of the Caribbean, andcoastal northern South America to Colombia.

The nominate form, herodias, breedsthroughout much of North America with theexception of western North America, wherethe race fannini occurs, which is darker andshorter-billed than herodias. In southernFlorida the entirely white form occidentalis islargely resident. Although this was formerlythought to be a separate species, hybrids withnominate herodias are known from theFlorida Keys, where they are known as ‘Wurdemann’s Heron’. An isolated race,cognata, breeds on the Galapagos Islands.

Acknowledgments

Norman Elkins kindly provided a summary of theweather leading up to 7th December 2007.

References

British Ornithologists’ Union (BOU). 2009. RecordsCommittee: 37th Report. Ibis 151: 224–230.

Casement, M. 1995. Great Blue Herons in the NorthAtlantic. Birding World 8: 424–425.

Clarke,T. 1999.The Great Blue Heron on Tenerife.Birding World 12: 158–161.

Dubois, P. J., & le CHN. 1997. Les oiseaux rares enFrance en 1996. Rapport du Comitéd’Homologation National. Ornithos 4 (4): 141–164.

Gantlett, S. 1998. Identification of Great Blue Heron.Birding World 11: 12–20.

Herroelen, P. 1995.A Great Blue Heron in the NorthAtlantic. Birding World 8: 356.

King, B. 1978. Great Blue and aberrant Grey Herons.Brit. Birds 71: 420.

— & Curber, R. M. 1972. Great Blue Herons coming onboard ships in mid Atlantic. Brit. Birds 65: 442.

Le Grand. G. 1986. Great Blue Herons on Azores inApril and June 1984. Dutch Birding 8: 55–57.

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E. Ashley Fisher, Trehill, Silvester’s Lane, St Mary’s, Isles of Scilly TR21 0NA

Editorial commentAdam Rowlands, Chairman of BBRC, commented: ‘The identification of Great Blue Heron in avagrant context has been well covered (e.g. Gantlett 1998). The occurrence of this species in theUK has long been anticipated, but it is still a considerable credit to the bird’s finder that he hadan active search-image for this species and was able to confirm the identification and spread thenews very quickly. Despite the heron being a one-day occurrence, the finder also submitted excel-lent documentation in support of the claim, which made the assessment of the identificationstraightforward for BBRC.’

Bob McGowan, Chairman of BOURC, commented: ‘This was one of the more straightforwardassessments for a potential addition to Category A in the last few years, not least due to the veryhigh standard of the submission documentation, including good-quality images. Identification ofa juvenile Great Blue Heron was easily established. There was no evidence to suggest that the birdhad benefited from assisted passage or any evidence of possible escape risk in Europe. Equally,the age of the bird, the date, weather and locality were convincing for genuine vagrancy. Withoutbiometrics, a definitive statement on racial identity was impossible, though the Committeerecognised that nominate herodias is the most likely on the basis of distribution and migratorybehaviour. Following a speedy electronic circulation of the record, Great Blue Heron was unani-mously accepted to Category A (BOU 2009).’


The recent establishment of breedingpairs of Eagle Owls Bubo bubo in York-shire and Lancashire has generated a

great deal of publicity in recent years and hassparked a debate about whether the speciesshould be considered a native part of theBritish avifauna (see Melling et al. 2008 for areview). The presence of jesses (leather strapsused in falconry) indicated that one memberof a pair nesting in Lancashire in 2006 wasindeed an escaped captive bird and manyconservation organisations, including theRSPB, maintain that Eagle Owls should prob-ably not be considered a native element ofthe British avifauna. However, there is specu-lation that there could be as many as 40 pairsnesting in the UK (Dennis 2005) and analternative view among the birding commu-nity is that the Eagle Owl should be consid-ered a native British species. This is not apedantic point. Its status has profound impli-

cations for the Eagle Owl’s conservation andwelfare. Calls have been made for breedingEagle Owls to be culled, to protect nativespecies that may be predated by the owls.However, if included as part of the nativeBritish avifauna, the Eagle Owl would nodoubt be subject to a conservation pro-gramme to encourage its re-establishment.

Historically, the fossil and archaeologicalrecord suggests that the Eagle Owl (or aclosely related ancestor) had been present inBritain for up to 700,000 years until the endof the last ice age (Stewart 2007). However, in1996 the Eagle Owl was removed from theBritish List by BOURC (BOU 1997), basedon a lack of evidence that Eagle Owls havelived in Britain in a wild state for over 200years. Even though some pairs have bred inBritain, there is no evidence to suggest thatthese have involved wild birds, and some areknown to have been escapes (the species has

213© British Birds 103 • April 2010 • 213–222

Using stable isotopes to investigate theprovenance of an EagleOwl found in NorfolkAndrew Kelly, Kevin Leighton and Jason Newton

Abstract The stable isotopes of hydrogen, oxygen, carbon and nitrogen wereanalysed in two generations of feather growth in a second- or third-calendar-yearfemale Eagle Owl Bubo bubo found in Norfolk in November 2006.We found thatthe juvenile primaries and secondaries had a consistently low δ2H signature, whilesecond-generation remiges, and body feathers, revealed higher values.The patternin δ2H between the two generations of feathers from the Norfolk birdcorresponds with the known moult patterns of Eagle Owls and suggests that thetwo generations of feathers were grown in different geographical regions.Although there are a number of alternative explanations for the findings, it seemsmost likely that the owl was reared somewhere with low local δ2H precipitationvalues. An origin in Scandinavia, north-continental Europe or mid-continentalRussia is consistent with our findings, but we cannot rule out the possibility thatthe bird was reared in northern Britain, either in the wild or in captivity.


been held in captivity in Britain since the sev-enteenth century). The Eagle Owl is currentlyregarded as a non-native species in Britain(Dudley et al. 2006).

An alternative view is that Eagle Owls arecapable of flying across the North Sea andmay have colonised Britain from northernEurope or Scandinavia (e.g. Dennis 2005).Although the species is considered to be rela-tively sedentary, recent evidence has sug-gested that young birds may disperse widely.The breeding pair in Yorkshire produced 23young between 1997 and 2005 (Holling et al.2007) before the female was shot. One youngbird was recovered dead (having hit powerlines) over 200 km away in Shropshire theyear after fledging and another was founddead near Peebles, Borders, more than 150km from the nesting site. Ringing recordsfrom Norway show movements of betweeneight and 220 km (mean 95 km, n = 12), witha tendency for birds to move towards thecoast (Cramp 1985). In Switzerland, satellitetelemetry and radio-tracking studies showedthat young Eagle Owls left the natal sitebetween August and November, coveringbetween four and 35 km per night, and trav-elling up to 320 km in total before settling upto 100 km from the natal territory (Aebischeret al. 2005). More recently, another youngSwiss Eagle Owl moved a total of 480 kmafter leaving its parents, finally settling 120km from its natal territory (Aebischer et al.2010). One ringed in Finland was recoveredmore than 400 km from its natal area (A. Aebischer pers. comm.) and another fromSchleswig-Holstein, in Germany, where thespecies is expanding its range, was recoveredon the French Atlantic coast, having travelledat least 1,179 km (Hamann 2002). Clearly,individual birds are capable of large move-ments over land at least.

For the Eagle Owl to be admitted to theBritish List on the basis of natural occur-rence, there would need to be strong sup-porting evidence (Melling et al. 2008). Todate there have been no ring-recoveries ofcontinental Eagle Owls in Britain. This isperhaps not surprising given the smallnumber of individuals marked (see Mellinget al. 2008), and the lack of recoveries is notevidence that the species is incapable ofcrossing the North Sea. Stable-isotope ratios

(e.g. 2H/1H, expressed as δ2H) have been usedextensively in the past decade as a forensicmethod of determining the origins andmovements of migratory animals (e.g.Hobson et al. 2004, Rubenstein et al. 2004,Bearhop et al. 2005, Bowen et al. 2005, Netoet al. 2006, Fox & Bearhop 2008). Forexample, Bearhop et al. (2005) usedhydrogen-isotope ratios in the claws ofBlackcaps Sylvia atricapilla to infer dichoto-mous wintering areas of birds returning totheir breeding grounds in south-centralEurope. Neto et al. (2006) used hydrogen,carbon and nitrogen isotope ratios in con-junction with the known moult pattern ofSavi’s Warblers Locustella luscinioides to showthat the isotope ratios of feathers grown inEurope differed significantly from thosegrown in the birds’ wintering grounds in sub-Saharan Africa. Newton et al. (2006) found awide range of hydrogen isotope ratios in thefeathers of ‘Northern Bullfinches’ Pyrrhula p.pyrrhula sampled from Scotland, Denmark,Sweden and the Amur region of Siberia, withthose from Sweden and Amur being signifi-cantly more depleted in deuterium (2H). Foxet al. (2007) used both hydrogen and oxygenisotope ratios in an analysis of the feathers ofa Baikal Teal Anas formosa shot in Denmarkin 2005, and distinguished juvenile featherswith a strongly continental signature frompost-juvenile ones with a signature moretypical of a moist, coastal European environ-ment. Stable isotopes of hydrogen have alsobeen used to infer the origins of GoldfinchesCarduelis carduelis trapped in northeasternEurope and imported into the UK illegally(Kelly et al. 2008).

Here, we used stable-isotope analysis toinvestigate the provenance of a second- orthird-calendar-year female Eagle Owl foundin Norfolk in November 2006. The bird hadno rings and there was no evidence (such asfeather wear on the primaries) to suggest thatit had been held in captivity. We comparedthe isotope ratios in the primaries, second-aries and body feathers of the Norfolk birdwith those collected from the carcases of fivewild-bred Eagle Owls from Norway, twofrom the Netherlands, and a known captivebird found dead near Bristol.

We tested the hypothesis that the Norfolkbird had crossed the North Sea and predicted

214 British Birds 103 • April 2010 • 213–222

Kelly et al.


that the stable-isotope signatures of juvenilefeathers would be similar to those found incontinental Eagle Owls. We compared thehydrogen isotope ratios of the feathers withthose shown in maps (‘isoscapes’) depictingthe predicted isotope ratios of precipitationacross north and central Europe(www.waterisotopes.org). We are well awareof the limitations of this approach and recog-nise that assigning geographical origin basedon isotope maps can be misleading unless thetissue samples are compared with those ofknown origin (Wunder et al. 2005). However,our intention is to contribute to the body ofevidence concerning the status of the EagleOwl in Britain, rather than to determine con-clusively the origin of the Norfolk bird.

On the basis of the known moult patternsof Eagle Owls (Niiranen & Haapala 1987), welooked for dichotomous origins of feathersand predicted that, if the bird had originatedin continental Europe or Scandinavia, weshould be able to differentiate between juven-ile feathers grown at the natal site and post-juvenile feathers grown in Britain. As acontrol for hydrogen isotope ratios, we alsocompared the feather samples with those

from two Tawny Owls Strix aluco fromNorfolk (a sedentary and resident species).

In addition, we also measured the carbonand nitrogen stable-isotope ratios of thefeathers. This was partly in an attempt todetect any dietary differences among thebirds in this investigation; carbon isotoperatios are a broad indicator of carbon sourcefor the diet, for example C3 or C4 primaryproduction, whereas nitrogen isotope ratiosgenerally indicate the trophic level at whichthese birds are feeding. Secondly, despite thecaveats just mentioned, in conjunction withthe hydrogen isotope measurements, δ13Cmay confirm or support any geographicalinferences made from the δ2H results (Netoet al. 2006).

MethodsCircumstances, identification andassessment of moult statusOn 20th November 2006, a large owl wasfound in an aircraft hangar at the formerRAF base at Watton, Norfolk, by a member ofthe public. The bird was subsequently col-lected by an RSPCA Animal CollectionOfficer and taken to RSPCA East Winch


Eagle Owl provenance using stable isotopes

113. Eagle Owl Bubo bubo, Helsinki, Finland, December 2006.

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Wildlife Centre, where it was identified by KL(a BTO A-permit ringer) as an Eagle Owl,based on its appearance and measurements.The bird was examined by a veterinarysurgeon and was found to be emaciated andto have an injured eye. Owing to its poorprognosis, it was subsequently euthanised toprevent further suffering. A post-mortemexamination revealed that it was a female. Itswing length (max. chord) was 483 mm,placing it in the mid/upper range for thenominate race bubo (Snow & Perrins 1998).

The moult of Eagle Owls is poorly knownand the following account is based onNiiranen & Haapala (1987). Juveniles have adark band near the tip of the primaries, sec-ondaries and tail feathers, but in the case ofpost-juvenile feathers this dark bar tends tobe farther from the feather tip. There is largevariation in the moult pattern of Eagle Owlsand individuals typically show distinctlyasymmetric patterns of wing moult. Primarymoult usually starts from two focus points.The first series starts at P6/P7 (primariesnumbered descendantly, in other words P10is the outermost), proceeding inwards andtowards the tip, but before the outermost pri-maries are dropped a second series startsfrom P1. In most cases P3 or P10 is the last tobe moulted. Secondary moult proceeds fromthree focus points, starting with S16 (theinnermost) and moving towards the wing-tip. The second series starts at S5 and thethird series at S2; in most cases, the outer-most (S1) is the last to be moulted. Niiranen& Haapala (1987) stated that Eagle Owlsundergo a partial moult between May andOctober during which the body feathers andsome wing-coverts are replaced. The inner-most secondaries and the tertials are alsoreplaced. Typically, all the tail feathers arereplaced between the second and third cal-endar-year. However, primary moult doesnot start until the third calendar-year, withP6 or P7 being replaced first.

The moult details of the Norfolk EagleOwl were as follows (with feathers classifiedas adult- or juvenile-type according topattern and wear):Left wing P1–P6 juvenile (-type), P7 adult

(type), P8–P10 juvenile, S1–S6 juvenile,S7–S14 adult, tertials adult (S15–S16missing)

Right wing P1–P7 juvenile, P8 adult, P9–P10juvenile, S1–S3, S6–S7 juvenile, S4–S5,S8–S15 adult, tertials adult (S16 missing)

Tail T1–T4 adult, T5–T6 juvenile (where T1is the innermost)

Based on this information, the Norfolk specimen was considered to be a second-/third-calendar-year bird.

SamplingP1–P10 and S1–S14 were taken from the leftwing of the Norfolk specimen and placed inpolythene sample bags. Tail feathers T1–T6(left side) and a small number of bodyfeathers removed from the breast weretreated similarly. Primary, secondary andbreast feathers were taken from two adultEagle Owls from the Netherlands and sec-ondaries were taken from five adult EagleOwls from Norway. All the birds from theNetherlands and Norway were recentlyarchived specimens. Primary, secondary andbreast feathers were also taken from twoadult Tawny Owls from Norfolk and a deadadult Eagle Owl found in Bristol, which wasknown to be an escaped captive-bred bird. Inaddition, the outermost primary, outermostsecondary and breast feathers of two adultEagle Owls captive-bred in the UK were col-lected. Table 1 lists the feathers sampled fromeach bird. Primaries, secondaries and bodyfeathers were requested for the Norwegianand Dutch birds, but only secondaries wereavailable from the Norwegian birds.

SI preparation and analysisThe methodology is given in Appendix 1. Fora full explanation of the stable-isotope tech-nique and its application to ornithology, seeFox & Bearhop (2008).

ResultsHydrogen and oxygen isotopemeasurementsFor the Norfolk Eagle Owl, the δ18O valuesoverlapped considerably: for juvenile-typefeathers 11.9–19.0‰ (mean 16.6, SE ±0.4‰)and for adult-type feathers 12.8–17.4‰(15.8, ±0.4‰).

Hydrogen isotope ratios of feathers fromthe Norfolk bird showed a clear pattern (seefig. 1). P7, S7–S14, T1–T4 and breast feathersof the Norfolk Eagle Owl were enriched in


Kelly et al.


2H, relative to P1–P6, P8–P10 and S1–S6. Theδ2H values for juvenile-type feathers rangedfrom -86.9‰ to -96.5‰ (mean -90.1, SE±0.5‰) and for adult-type feathers from -24.0‰ to -61.7‰ (-43.8, ±2.7‰). Therewas no overlap in the δ2H values for juvenile-and adult-type feathers.

The δ2H of the Norwegian Eagle Owls alsoshowed a wide variation, from -1.7‰ to -80.3‰ (-50.6, ±15.3‰) (see fig. 2). Thismay be related to the variation in latitudefrom which the birds were obtained(58–69°N) or, alternatively, to the proximityof the ocean of sites from which the sampleswere obtained. The Norwegian owls con-sisted of three females and two males. Inter-estingly, the three birds closest in δ2H values

to the Norfolk owl were all females, while thetwo most enriched birds were males.However, the reasons for this are not clearand the small sample size makes interpreta-tion difficult.

Dual hydrogen and carbon isotope ratiosof feathers from the birds from the Nether-lands and Norway, two wild-bred TawnyOwls and known captive-bred Eagle Owls areshown in fig. 2.

Carbon and nitrogen isotopemeasurementsThe δ13C values of feathers from the NorfolkEagle Owl formed a narrow range, from -23.9‰ to -22.3‰. Most of the other UKsamples, including those from the Tawny



Table 1. Feathers sampled from the Norfolk Eagle Owl Bubo bubo, from wild-bred Eagle Owlsfrom the Netherlands and Norway, and from captive-bred Eagle Owls from Bristol and Wales.Samples from wild Tawny Owls Strix aluco bred in Norfolk are included for comparison.

Species Status Source Feather type Description

Eagle Owl Unknown Norfolk Primary P1–P10 Secondary S1–S14Body BreastTail T1–T6

Eagle Owl Wild Netherlands Primary P10Secondary S5Body Breast

Eagle Owl Wild Netherlands Primary P10Secondary S5Body Breast

Eagle Owl Wild Norway Secondary S5





Eagle Owl Captive Bristol Primary P4Secondary S1Body Breast

Eagle Owl Captive Wales Primary P10Secondary S1Body Breast

Eagle Owl Captive Wales Primary P10Secondary S1Body Breast

Tawny Owl Wild Norfolk Primary P10Secondary S1Body Breast

Tawny Owl Wild Norfolk Primary P10Secondary S1Body Breast


Owls, were similar to the Norfolk Eagle Owlvalues, or slightly more 13C-rich. The Dutchand (in particular) the Norwegian feathersamples appear to show a positive relation-ship between δ13C and δ2H, which could beindicative of a marine influence in the signa-ture of the feathers.

The δ15N values of feathers from theNorfolk Eagle Owl ranged from +8.3 to+11.5‰. Most other groupings lie in thesame δ15N range, with the exception of oneof the Tawny Owl samples, which has featherδ15N values ranging from +2.6 to +5.3‰. Itis most likely that this Tawny Owl wasfeeding at least one trophic level below the

other individuals in this study. The adultfeathers from the Norfolk Eagle Owl weresignificantly enriched in 15N and slightly (butnot significantly) enriched in 13C comparedwith the juvenile feathers. This is probablydue to a change in the trophic level betweenthe juvenile and adult stages. An alternativeexplanation is that a marine influence in thediet has resulted in enrichment of 15N and13C. However, this is unlikely since thenatural prey of Eagle Owls is terrestrial.

DiscussionThe results from our analyses suggest thatthe two generations of feathers of the

Norfolk Eagle Owl weregrown in different climaticregions. P7 and S7–S14(adult feathers) were clearlyenriched in deuterium rela-tive to the juvenile primariesand secondaries. The δ2H ofthe juvenile feathers layoutside the range of valuesfound for the other EagleOwls, of known origin,measured here and wouldperhaps be consistent withan origin farther east in con-tinental Europe where theenvironmental δ2H is lower.The δ2H values of the adult-type feathers from theNorfolk Eagle Owl weresimilar to those of the Nor-wegian Eagle Owls and UKTawny Owls and showed amarked difference fromthose of the captive-bred(UK) Eagle Owls. In terms ofcarbon and nitrogen iso-topes, only the nitrogenisotope ratio differedbetween the juvenile- andadult-type feathers, indi-cating a marginal increase introphic level.

Owing to the limitationsof stable-isotope techniquesto pinpoint origins precisely,we cannot rule out the fol-lowing alternative explana-tions for the very low δ2H


Kelly et al.

Fig. 1. Dual isotope plot for feathers from the Norfolk Eagle OwlBubo bubo.The closed circles (2H depleted) represent the juvenile-type feathers and the open circles (2H enriched) represent theadult-type feathers.

-22.2

-22.4

-22.6

-22.8

-23.0

-23.2

-23.4

-23.6

-23.8

-24.0

-24.2

δ13 C

juvenile-type

-100.0 -90.0 -80.0 -70.0 -60.0 -50.0 -40.0 -30.0 -20.0δ2H

adult-type

breast

Fig. 2. Dual carbon and hydrogen isotope plot showing the widerange of δ2H values for the sampled feathers from the NorfolkEagle Owl Bubo bubo (juvenile- and adult-type feathers), Eagle Owlsfrom the Netherlands and Norway,Tawny Owls Strix aluco fromNorfolk and captive Eagle Owls from the UK.

-15.0

-17.0

-19.0

-21.0

-23.0

-25.0

-27.0

δ13 C

Norfolk (juvenile-type)Norfolk (adult-type)NetherlandsNorwayTawny OwlCaptive Eagle Owl

-100.0 -80.0 -60.0 -40.0 -20.0 0.0δ2H


values of the first-genera-tion feathers:1. The Norfolk bird was

captive-bred and hadbeen fed on 2H-depletedfood before escaping andsubsequently living for asubstantial period in thewild, with post-juvenilefeathers reflecting itsenvironment.

2. The bird was captive-bred and had been fed2H-depleted food for thefirst year before switchingto a 2H-enriched diet inits second calendar-year,prior to escaping.

3. The bird was captive-bred or wild-caught in anarea where the δ2H valueof precipitation is lowand was then transportedto East Anglia beforeescaping or beingreleased.

4. The bird was wild buthad hatched in a regionof the UK with depletedlocal δ2H values.

5. Physiological differencesbetween the juvenile andadult stage result in dif-ferences in the way δ2H is incorporated into feathers (a growtheffect).There is no evidence to suggest that

captive-bred birds in the UK are fed on 2H-depleted food, although the δ2H valuesrecorded in the feathers of captive birds wereconsiderably lower than those of the otherspecimens. Most captive-bred Eagle Owls inthe UK are fed on day-old chicks, sourced inthe UK (Gary Dickenson pers. comm.) andso are most likely to reflect δ2H values of UKprecipitation. Explanations 1 and 2 requirethat the food fed to a captive-bred bird wassourced from raw materials derived fromareas with low δ2H precipitation values. Interms of explanation 3, Eagle Owls are listedon Annex A of CITES, with trade strictlycontrolled, and birds legitimately involved intrade are required to be permanently



114. Eagle Owl Bubo bubo, Helsinki, Finland, November 2006.M

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marked; consequently, explanation 3 isunlikely (although illegal importationremains a possibility).

Explanation 5 is not compelling. We canthink of no reason why juvenile and adultstages may differ in the way δ2H is incorp-orated into feathers, and it is extremelyunlikely that annual changes in δ2H would beas marked as the differences we observedbetween the juvenile- and adult-type feathersof the Norfolk bird.

We cannot rule out (and cannot test for)explanation 4, that the bird hatched in thewild in the UK in a region with low local δ2Hvalues before moving to Norfolk. Certainly,published data suggest that δ2H values innorthern Britain and Scandinavia are similar(Bearhop et al. 2005), while Newton et al.(2006) showed that resident Scottish


Bullfinches (subspecies pileata) had δ2Hvalues similar to those of the juvenile-typefeathers from the Norfolk Eagle Owl. Thepossibility exists, therefore, that this bird mayhave hatched in an area of Scotland with lowlocal δ2H values (in the wild or, indeed, incaptivity) before moving (or being moved)south to Norfolk.

The juvenile-type feathers suggest that theNorfolk bird’s natal area was characterised byprecipitation with very low δ2H values. Suchconditions occur in Scandinavia, north-con-tinental Europe and mid-continental Russia– where Eagle Owls are known to occur – butalso in northern parts of the UK (Hobson etal. 2004; Bowen et al. 2005). For example, theδ2H values of the first-generation feathersfrom the Norfolk Eagle Owl were similar tothose of Grey Partridges Perdix perdix andEurasian Curlews Numenius arquata fromRussia and of Fieldfares Turdus pilaris andRedwings Turdus iliacus from Finland(Hobson et al. 2004); but also similar to thoseof resident Scottish Bullfinches (Newton etal. 2006). Unfortunately, as discussed above,stable-isotope analysis is not sufficientlyprecise to identify the natal area of this birdand, in fact, the alternative explanations forthe observed isotopic differences between thejuvenile and adult-type feathers listed aboveillustrate well the limitations of the tech-nique.

The strongest objection to Eagle Owlsappearing in the UK as natural vagrantsappears to be their relatively sedentarybehaviour and reluctance to cross largeexpanses of water (Melling et al. 2008).However, although ringing recoveriesconfirm that Eagle Owls are largely seden-tary, they are clearly capable of moving longdistances, at least over land, as the examplesgiven at the beginning of this paper show.Indeed, the fact that young birds in Switzer-land have been shown to move up to 480 kmbefore settling prompted Aebischer et al.(2010) to call for transnational conservationefforts. Moreover, the Eagle Owl’s range hasbeen spreading in western Europe, despitedeclines in many European countries (Hage-meijer & Blair 1997). Although there is noconclusive evidence of the species under-taking a major sea crossing, natural vagrancymay not be as unlikely as suggested by

Melling et al. (2008).In future, it may be possible to identify the

origin of Eagle Owls genetically usingmicrosatellite markers developed in a captivepopulation used to reinforce the Eagle Owl inSweden (Isaksson & Tegelstrom 2002). Untilthen, stable isotopes may provide furtherinformation on possible vagrants. We wereunable to obtain samples from any of theYorkshire Eagle Owls and it would be inter-esting to compare the δ2H of Eagle Owlsknown to have been raised in the UK withthose from continental Europe and captive-bred birds. We recommend that isotopicvalues of feathers of Eagle Owls of unknownprovenance discovered in Britain in futureshould be measured and compared withthose of specimens of known provenance.

Acknowledgments

Thanks to Hugh Jansman, Centre for EcosystemStudies, the Netherlands for providing samples; RoyDennis, Duncan Halley and Nils Røv, NorwegianInstitute for Nature Research, for providing samplesfrom five Eagle Owl specimens from the museum atthe Norwegian University of Science and Technology(NTNU) in Trondheim; Lee Walker from the Centrefor Ecology and Hydrology for samples from an EagleOwl (an escaped captive) from Bristol; and GaryDickenson for feathers from two captive-bred EagleOwls from Wales. Thanks also go to Reijo Kakela fortranslating a paper on the moult of Eagle Owls and toAdam Grogan for useful discussions. Finally the authorswould like to thank Stuar t Bearhop for helpfulcomments which greatly improved the manuscript.

References

Aebischer,A., Nyffeler, P., & Arlettaz, R. 2010.Wide-range dispersal in juvenile Eagle Owls (Bubo bubo)across the European Alps calls for transnationalconservation programmes. J. Orn. 151: 1–9.

—, —, Koch, S., & Arlettaz, R. 2005. Jugenddispersionund Mortalität Schweizer Uhus Bubo bubo – einaktueller Zwischebericht. Ornithologischer Anzeiger44: 197–200.

Bearhop, S., Fiedler,W., Furness, R.W.,Votier, S. C.,Waldron, S., Newton, J., Bowen, G. J., Berthold, P., &Farnsworth, K. 2005.Assortative mating as amechanism for rapid evolution of a migratorydivide. Science 310: 502–504.

Bowen, G. J.,Wassenaar, L., & Hobson, K.A. 2005.Global application of stable hydrogen and oxygenisotopes to wildlife forensics. Oecologia 142:337–348.

British Ornithologists’ Union (BOU). 1997. RecordsCommittee: twenty-third report (July 1996).Ibis 139: 197–201.

Cramp, S. (ed.) 1985. The Birds of the Western Palearctic.Vol. 4. OUP, Oxford.

Dennis, R. 2005.The Eagle Owl has landed. BBC Wildlife23 (13): 24–29.


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Dudley, S. P., Gee, M., Kehoe, C., Melling,T. M., & theBOURC. 2006.The British List: a checklist of birds ofBritain (7th edn). Ibis 148: 526–563.

Farquhar, G. D., Henry, B. K., & Styles, J. M. 1997.A rapidon-line technique for determination of oxygenisotope composition of nitrogen-containing organicmatter and water. Rapid Communications in MassSpectrometry 11: 1554.

Fox,A. D., & Bearhop, S. 2008.The use of stable-isotope ratios in ornithology. Brit. Birds 101:112–130.

—, Christensen,T. K., Bearhop, S. B., & Newton, J. 2007.Using stable isotope analysis of differing feathertracts to identify moulting provenance of vagrantbirds – a case study of Baikal Teal Anas formosa inDenmark. Ibis 149: 622–625.

Hagemeijer,W. J. M., & Blair, M. J. 1997. The EBCC Atlasof Breeding Birds: their distribution and abundance.Poyser, London.

Hamann, C. 2002. Uhu aus Schleswig-Holstein flog bisan die französische Atlantik-Küste. EulenWelt 2002:24–25.

Hobson, K.A., Bowen, G. J.,Wassenaar, L. I., Ferrand,Y., &Lormee, H. 2004. Using stable hydrogen and oxygenisotope measurements of feathers to infergeographical origins of migrating European birds.Oecologia 141: 477–488.

Holling, M., & the Rare Breeding Birds Panel. 2007.Non-native breeding birds in the United Kingdom in2003, 2004 and 2005. Brit. Birds 100: 638–649.

Isaksson, M., & Tegelstrom, H. 2002. Characterization ofpolymorphic microsatellite markers in a captivepopulation of the Eagle Owl (Bubo bubo) used forsupportive breeding. Molecular Ecology Notes 2:91–93.

Kelly,A.,Thompson, R., & Newton, J. 2008. Stablehydrogen isotope analysis as a method to identifyillegally trapped songbirds. Science and Justice 48:67–70.

Kornexl, B. E., Gehre, M., Höfling, R., & Werner, R.A.1999. On-line 18O measurement of organic andinorganic substances. Rapid Communications in MassSpectrometry 13: 1685–1693.

Melling,T., Dudley, S., & Doherty, P. 2008.The Eagle Owlin Britain. Brit. Birds 101: 478–490.

Neto, J. M., Newton, J., Gosler,A. G., & Perrins, C. M.2006. Using stable isotope analysis to determine thewinter moult extent in migratory birds: the complexmoult of Savi’s Warblers. J. Avian Biol. 37: 117–124.

Newton, I., Hobson, K.A., Fox,A. D., & Marquiss, M.2006.An investigation into the provenance ofNorthern Bullfinches Pyrrhula p. pyrrhula found inwinter in Scotland and Denmark. J. Avian Biol. 37:431–435.

Niiranen, S., & Haapala, J. 1987. Huuhkajan iänmäärittäminen. Lintumies 20: 112–116.

Rubenstein, D. R., & Hobson, K.A. 2004. From birds tobutterflies: animal movement patterns and stableisotopes. Trends in Ecology and Evolution 19:256–263.

Snow, D.W., & Perrins, C. M. (eds.) 1998. The Birds ofthe Western Palearctic. Concise edn. OUP, Oxford.

Stewart, J. R. 2007.The fossil and archaeological recordof the Eagle Owl in Britain. Brit. Birds 100: 481–486.

Wassenaar, L. I. 2008.An introduction to light stableisotopes for use in terrestrial animal migrationstudies. In: Hobson, K.A., & Wassenaar, L. I. (eds.),Tracking Animal Migration with Stable Isotopes.Elsevier,Amsterdam.

— & Hobson, K.A. 2003. Comparative equilibrationand online technique for determination of non-exchangeable hydrogen of keratins for use in animalmigration studies. Isotopes in Environmental HealthStudies 39: 211–217.

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Andrew Kelly, RSPCA Stapeley Grange Wildlife Centre, London Road, Stapeley, Nantwich,Cheshire CW5 7JW; and School of Biological Sciences, Medical Biology Centre, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL (correspondence address)

Kevin Leighton, RSPCA East Winch Wildlife Centre, East Winch, Norfolk PE32 1NRJason Newton, NERC Life Sciences Mass Spectrometry Facility, Scottish Universities Environmental

Research Centre, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride G75 0QF

Appendix 1.SI preparation and analysisHydrogen/oxygen isotope measurementsFeathers were washed in 2:1 chloroform:methanol and dried at room temperature under a fumehood. A small section of mass 0.6–0.8 mg was clipped from the end of all feathers. In the case ofthe large primaries, small sections were cut from the tip, middle and base. In each case, thesample was weighed into individual silver capsules for hydrogen and oxygen isotope analysis.Isotope ratios were measured via continuous-flow stable-isotope mass spectrometry (CF-IRMS),using a Costech ECS 4010 elemental analyser in oxygen mode with high-temperature inductionfurnace (HTG-02) interfaced with a ThermoFisher Scientific Delta V Plus isotope ratio massspectrometer, at the East Kilbride node of the NERC Life Sciences Mass Spectrometry Facility(Scottish Universities Environmental Research Centre).

Repeat analyses of keratin standards incorporated into each hydrogen sample run showed thatδ2H is measured with an accuracy and precision of ±2‰. Keratin standards CFS (chicken


feather), BWB-II (Bowhead Whale Balaena mysticetus baleen) (Wassenaar 2008) in conjunctionwith an internal standard ISB (Icelandic Kittiwake Rissa tridactyla feather) were used to correctsamples for isotopic exchange between labile hydrogen in feathers and ambient water vapour inthe laboratory using a comparative equilibration method (Wassenaar & Hobson 2003). The δ18Ovalues of samples were compared to those of the reference materials IAEA CH6 (sucrose, Far-quhar et al. 1997, Kornexl et al. 1999) and IAEA 601 and 602 (benzoic acid), though we recognisethat the samples here are 18O-poor with respect to the standards used.

Carbon/nitrogen measurementsSections of the tips of all cleaned feathers were cut and transferred into 3 x 5-mm tin capsules,which were then measured by CF-IRMS, using a Costech ECS 4010 elemental analyser in CHNSmode interfaced with a ThermoFisher Scientific Delta V Plus isotope ratio mass spectrometer, atthe East Kilbride node of the NERC LSMSF.

Samples were measured against internal standards gelatin and two alanines with disparatecarbon and nitrogen stable-isotope ratios. Long-term reproducibility is around 0.2‰ for d15Nand 0.1‰ for δ13C.

Stable-isotope ratios are expressed as the normalised ratio of the sample to a primaryinternational standard, in parts per thousand (per mil, ‰):

δX = [(Rsample /Rstandard) – 1] x 1,000

where Rsample and Rstandard are the ratios of heavy to light isotopes for the sample and the standardrespectively. Rstandard for both d2H and d18O is Standard Mean Ocean Water (SMOW). Rstandard forδ13C is the Pee Dee Belemnite (PDB) and that for d15N is atmospheric nitrogen (AIR).


Kelly et al.


This short paper describes a study of thebreeding population of NorthernWheatears Oenanthe oenanthe at Clee

Hill, Shropshire, which was instigated inresponse to the Retrapping Adults for Sur-vival (RAS) project set up by the BTO in1998 to encourage ringers to collect high-quality information on survival rates. Priorto 1998, Chelmarsh Ringing Group had beenlocating Wheatear nests and ringing pulli at

Clee Hill, but from 1998 onwards adults havealso been trapped and ringed.

Study area and methodsThe study area covers some 700 ha of uplandcommon land (at an altitude of some400–500 m) in southern Shropshire. Sincethe latter part of the nineteenth century,Dhustone (dolerite), a hard volcanic rockused in road construction, has been quarried


The breeding populationof Northern Wheatearsat Clee Hill, Shropshire,1998–2009Dave FultonAbstract The breeding population of Northern Wheatears Oenanthe oenanthe atClee Hill, Shropshire, has been monitored since 1998 as part of the BTORetrapping Adults for Survival project. Aspects of breeding biology, including layingdates, clutch size and brood size are presented, together with estimates of thereturn rate of adult birds.There is some evidence that the local population may bedeclining, with 2009 being a particularly poor year; this may reflect a combinationof the national population trend and perhaps deterioration in the habitat forWheatears in the study area.

Rich

ard

Alle

n


from the area. Much of the local landscapehas been affected by the quarrying industryand the area is littered with derelict buildingsand redundant quarries, while rocks andscree habitat are plentiful. Sheep graze mostof the area and one large quarry is still opera-tional. The terrain is ideal for breedingWheatears, which nest in rock piles, underlarge rocks, in drystone walls, under the con-crete slabs of derelict buildings and occasion-ally in rabbit burrows. Surprisingly, someprefer to nest within the busy workingquarry, despite having to travel farther toobtain food on the surrounding grassy slopesthan birds elsewhere in the study area.

The majority of nests are found bywatching the adults carrying food back totheir chicks. This is generally done from thecover of a vehicle, when observers are almostinvisible and can be within 10 m of the nestwithout disturbing the Wheatears. Adults aremuch more reluctant to return whenobservers are on foot. Most of the area isaccessible by car, although this is becomingincreasingly difficult as tracks are graduallybeing blocked to deter boy racers on quadbikes and in 4x4s. The same nest-sites areoften used year after year, mostly by a dif-ferent pair (although one member of the pre-vious pairing may often be involved – very

few pairs remaintogether in consec-utive years). A newnest is always con-structed alongsidethe old one, how-ever, and up to fivedifferent nests havebeen found underfavoured rocks.

To minimisedisturbance andthe possibility ofadults deserting thebrood, chicks arenot ringed untilthey are at least sixdays old. After aweek or so, theadults are surpris-ingly tolerant ofdisturbance; onone occasion,members of theringing grouparrived to ring abrood of nine-day-old chicks and dis-turbed a BadgerMeles meles, whichhad dug up theentire site. Fearingthe worst, welooked inside whatwas now a hugecavern to find sixterrified youngWheatears cow-


Fulton

115 & 116. The study site at Clee Hill, Shropshire, May 2009.

Dav

e Fu

lton

Dav

e Fu

lton


ering at the back. We spent half an hourrebuilding the site, remaking the nest andpulling in heavy boulders around the outsideto deter the Badger’s return. Within an hourof the new nest being completed, bothparents resumed feeding duties and theyoung fledged successfully a week later.

Initially, walk-in (Potter) traps were usedto catch adults but spring traps baited withmealworms have proved much more effec-tive. Traps are placed near the nest entranceand are normally successful within 10–15minutes. Adults are trapped only when theyhave young more than three days old sincethe adults may stay away from the nest for upto an hour after being caught. Adults arecolour-ringed, with a colour representing theyear of ringing above the BTO metal ring onthe left leg, plus two other colours on theright leg.

Results and discussionBreeding biologyBetween 1998 and 2009, a total of 505Wheatear nests were found in the study area,of which 297 were used to analyse timing ofbreeding, clutch size, brood size, etc. (onlythose for which the contents could bechecked accurately were used). These includereplacement clutches and a few secondbroods (see below).

First-egg date varied between 1st May and8th May, with a mean of 5th May and noobvious trend in the data. Interestingly,timing of breeding is later than that reported

for both Skokholm, Pembrokeshire, andDungeness, Kent (Conder 1989). It is notice-ably later than that for Skokholm, wherelaying begins in mid April and peaks in earlyMay; this presumably reflects the lowerminimum temperatures of the uplandShropshire study area in the weeks leading upto egg-laying.

Mean clutch size varied between 5.03 and6.12 in the 12 years at Clee Hill, with anoverall mean of 5.42 (national mean 5.45,n=470; Skokholm mean 5.7, n=131; Dunge-ness mean 5.3, n=97; http://blx1.bto.org/birdfacts/results/bob11460.htm, Conder1989). Mean brood size varied annuallybetween 4.43 and 5.67, with an overall meanof 5.06 (national mean 4.97, n=???; Skokholmmean 4.9, n=184; Dungeness 4.7, n=83). AtClee Hill, both parameters showed a slightbut not significant downward trend acrossthe 12 years.

Published literature implies thatWheatears rather commonly raise twobroods. For example, in Conder’s study of thebirds on Skokholm, he found that 47% of theWheatear pairs during 1948–53 laid secondclutches (Conder 1989). At Clee Hill, secondbroods appear to be the exception. In 1998,one pair raised two broods from the samenest (six and two young fledged, respec-tively); in 2002, two pairs were double-brooded, one using the same nest (six andfour young fledged, respectively), the othermaking a new nest (outcome of second nestnot known); and in 2008 a pair raised a


Northern Wheatears in Shropshire

Table 1. Breeding data from a population of Northern Wheatears Oenanthe oenanthe at Clee Hill,Shropshire, 1998–2009. Note that ‘nests used’ denotes the number of nests where contents couldbe checked accurately, and this figure therefore provides sample size for clutch size and brood size.

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 total/mean

nests found 43 44 46 36 35 41 41 66 55 44 35 19 505

nests used 39 37 20 26 29 22 17 30 28 27 14 8 297

first-egg date 7th 4th 6th 6th 3rd 5th 2nd 1st 7th 4th 8th 5th May May May May May May May May May May May May

eggs laid 225 199 111 138 146 115 104 173 145 139 71 43

clutch size 5.77 5.38 5.55 5.31 5.03 5.23 6.12 5.77 5.18 5.15 5.07 5.38 5.42

young hatched 221 185 104 127 138 104 90 162 139 131 62 41

brood size 5.67 5.00 5.20 4.88 4.76 4.73 5.29 5.40 4.96 4.85 4.43 5.13 5.06

pulli ringed(all nests) 222 184 119 124 148 106 94 159 150 138 66 50


second brood of three chicks (two eggs wereinfertile), after a disastrous first breedingattempt where just one chick hatched andfive eggs were infertile. These were the onlyinstances of true double broods in the 505nests found.

There were very few instances in whichthe same pair remained together in consecu-tive years, and new partners were the norm.This appears not to be survival-related; thereare lots of examples where the male andfemale from a pair both returned the fol-lowing year but bred with a new partner (e.g.three pairs in 2008, eight pairs in 2007). Justeight instances of a pair bond surviving fortwo consecutive seasons were recordedduring the twelve study years. On three occa-sions, once in 1999 and twice (involving twodifferent males) in 2006, a male paired simul-taneously with two females, and helped toraise each brood. No instances of adultspaired with their offspring were found in the12 seasons.


Fulton

Table 2. Distance between nesting attempts in different years according to age and sex classes(‘1Y’ refers to those ringed as chicks in one year, and observed as breeders in the study area in thesubsequent year).

Adult males Adult females 1Y males 1Y females

No. observed breeding in consecutive seasons 84 87 41 41

Mean distance between breeding attempts 250 m 341 m 1,041 m 1,013 m(adults) or between natal site and first breeding attempt (1Y)

Site fidelityDuring the 12 years of field-work carried out so far, itbecame clear that markedadults return in subsequentyears close to the previousyear’s nest, while first-yearsdisperse farther from theirnatal site. To investigate thisfurther, the distance betweennesting attempts in differentyears for the same individualbirds was measured, usingGoogle Earth mapping tech-nology (table 2). These resultsshowed clearly that, asexpected, the breeding dis-persal of adults was less thanthe natal dispersal of youngbirds.

There is, so far, no evidence from ringingreturns or sightings of colour-ringed birdsthat Clee Hill Wheatears move to otherbreeding locations.

Adult survivalBetween 1998 and 2009, a total of 156 adultmales and 204 adult females were trappedand colour-ringed. Tables 3 & 4 present theresighting data for these.

As suggested by the name, the RAS projectwas set up primarily to collect more informa-tion on the survival rates of adult birds.Complex calculations of survival rates arebeyond the scope of Chelmarsh RingingGroup so the analysis presented here is verybasic, showing the number of birds ringedeach year and the number of individuals inthat cohort that were seen in subsequentyears (return rate). This of course takes noaccount of any emigration from the site (seeabove), which any calculation of survival ratewould need to consider. Note that first-year

117. Colour-ringed female Northern Wheatear Oenantheoenanthe in the Clee Hill study area.

John

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Northern Wheatears in Shropshire

Table 3. Resighting rates for male Northern Wheatears Oenanthe oenanthe at Clee Hill,Shropshire, 1998–2009.

Same bird resighted after

Year ringed No. ringed 1 yr 2 yr 3 yr 4 yr 5 yr 6 yr 7 yr 8 yr

1998 20 3 2 1 0 0 0 0 01999 13 5 1 0 0 0 0 0 02000 18 7 5 4 2 1 0 0 02001 7 2 1 0 0 0 0 0 02002 13 8 3 3 2 1 1 0 -2003 6 4 4 1 0 0 0 - -2004 10 4 1 1 0 0 - - -2005 21 12 6 0 0 - - - -2006 15 5 3 1 - - - - -2007 20 3 7 - - - - - -2008 13 5 - - - - - - -

Totals 156 58Totals to 07 143 33Totals to 06 123 11Totals to 05 108 4Totals to 04 87 2Totals to 03 77 1Totals to 02 71 0Totals to 01 58 0

% return rate 37.2 23.1 8.9 3.7 2.3 1.3 0 0

Table 4. Resighting rates for female Northern Wheatears Oenanthe oenanthe at Clee Hill,Shropshire, 1998–2009.

Same bird resighted after

Year ringed No. ringed 1 yr 2 yr 3 yr 4 yr 5 yr 6 yr 7 yr 8 yr

1998 24 3 2 1 0 0 0 0 01999 19 1 0 0 0 0 0 0 02000 16 7 3 3 0 0 0 0 02001 12 4 1 1 1 1 0 0 02002 13 4 3 3 2 1 0 0 -2003 15 2 1 1 1 0 0 - -2004 17 10 1 0 0 0 - - -2005 34 10 6 1 0 - - - -2006 25 10 5 3 - - - - -2007 20 5 4 - - - - - -2008 9 2 - - - - - - -

Totals 204 58Totals to 07 195 26Totals to 06 175 13Totals to 05 150 4Totals to 04 116 2Totals to 03 99 0Totals to 02 84 0Totals to 01 71 0

% return rate 28.4 13.3 7.4 2.7 1.7 0 0 0


birds, ringed the previous year as pulli, arenot colour-ringed and must be trapped asbreeding birds to be fitted with colour ringsand added to this analysis (first-years are easyto trap at the nest, however, so not many aremissed). The tables assume that when firsttrapped the birds were in their first summer;however, 25% of those trapped were aged as asecond-summer or older, so a quarter ofthese birds survived at least one additionalyear than shown here.

The Clee Hill data suggest that full-grownWheatears are unlikely to return for morethan six years. The data also suggest thatmales have a slightly higher return rate thanfemales, which could be related to the extrastress of the breeding cycle on females (whichincludes taking on the majority of chick-feeding duties). One exceptional male wasfirst ringed as a pullus on 28th May 1995 andretrapped on 31st May 2003; this individualcurrently holds the BTO longevity record forthis species, of eight years and three days(Coiffait et al. 2008).

Local movements and migrationsConsidering the number of birds ringed, andthe fact that most adults are colour-ringed,the number of controls/resightings outsidethe study area is extremely poor. Two pullihave been controlled outside Shropshire: oneringed on 29th May 1997 was controlled inBeni Frassen, Morocco, on 16th September1998; another, ringed on 22nd May 2002, wascontrolled in Devon on 21st March 2006.Finally, an adult male trapped at Clee Hill on22nd May 2005 was controlled in Hampshirethe following spring, on 25th March 2006.

Long-term prospects for theWheatears at Clee HillThe number of nests found in 2009 was anall-time low for the site, and any furtherdecline in numbers will ring alarm bells for

the long-term sustainability of the popula-tion. The 2010 season is eagerly awaited, butit is feared that this recent decline may belinked to habitat changes in the Clee Hillarea. Although a large part should remainuntouched, recent changes in farming,affected in particular by the nature and avail-ability of subsidies, may reduce the numberof sheep grazing the area. Wheatears feed onthe short swards produced by sheep grazing,and this is an essential component of thelocal habitat for this breeding population. Inaddition, when quarried seams are finallyobsolete, the quarry company is under con-tract to fill in and return the land to ‘normal’.In practice, this means levelling the groundand sowing coarse, quick-growing grass. Thisgenerally remains ungrazed by sheep, whilerocks and other ‘untidy’ potential Wheatearnesting areas are cleared away, all of whichcreates pressure on the Wheatear populationat the site. A national decline in Wheatearnumbers should also be borne in mind.Breeding Bird Survey figures for the UK as awhole during 1995–2007 show a decline of11%, and for the same period there is a 24%decline in Wales. As well as local habitatchanges, the national population trend(which may reflect factors operating on thewintering grounds and at migrationstopovers) may be implicated in the changesobserved.

Acknowledgments

Par ticular thanks are due to Dave Bastin, TonyCrossman and Joe Jordan, fel low members ofChelmarsh Ringing Group, who have been stalwarthelpers in collecting the data presented here.

References

Coiffait, L., Clark, J. A., Robinson, R.A., Blackburn, J. R.,Griffin, B. M., Risely, K., Grantham, M. J., Marchant, J. H.,Girling,T., & Barber, L. 2008. Bird ringing in Britainand Ireland in 2006. Ringing & Migration 24: 15–79.

Conder, P. 1989. The Wheatear. Christopher Helm,London.


Fulton

Dave Fulton, 6 Hazelwells Road, Highley, Shropshire WV16 6DJ



The decline of the Ring Ouzel in BritainInnes Sim, Chris Rollie, David Arthur, Stuart Benn,Helen Booker, Vic Fairbrother, Mick Green, KenHutchinson, Sonja Ludwig, Mike Nicoll, Ian Poxton,Graham Rebecca, Leo Smith, Andrew Stanburyand Pete Wilson

Ben

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Conservation Priority Species

Abstract The Ring Ouzel Turdus torquatus is a Red-listed, UK Biodiversity ActionPlan priority species in Britain because of steep declines in breeding numbers overthe past 25 years. Data from several monitoring projects, from across much of thespecies’ British range, show that widespread declines continue. Recent studiesaimed at understanding these declines are reviewed, and suggest that low first-year, and possibly adult, survival may be the main demographic mechanism drivingthe decline. The research priorities are now to identify the factors affectingsurvival, determine where these factors are operating, and find managementsolutions.


The Ring Ouzel Turdus torquatus breedsin mountainous regions throughoutEurope, and in southwest Asia. Three

races are recognised: nominate torquatusbreeds in Britain & Ireland andFennoscandia, and winters in southern Spainand northwest Africa, especially in the AtlasMountains of Morocco and Algeria; thecentral and southern European race T. t.alpestris breeds in central and southernEurope and winters in the south of thebreeding range or in northwest Africa, thuslargely overlapping with the winter range ofnominate torquatus; and the eastern race T. t.amicorum breeds in the mountains of south-west Asia, east to northern Iran, and isthought to winter in Iran and southern Turk-menistan (Cramp 1988; Janiga & Poxton1997).

In Britain the Ring Ouzel is primarily abird of the uplands, breeding mainly insteep-sided valleys, on crags and in gullies,from near sea level in the far north of Scot-land up to 1,200 m in the Cairngorms(Cramp 1988; Gibbons et al. 1993; Rollie2007). The breeding season stretches frommid April to mid July; pairs commonly reartwo broods, and nests are located on or closeto the ground, in vegetation (typicallyHeather Calluna vulgaris), in a crevice or,rarely, in a tree. Mean clutch size is 3.9–4.2and mean fledged brood size is 3.5–3.8.Young are fed an invertebrate diet consistingmainly of earthworms (Lumbricidae),leatherjacket (Tipulidae) larvae and beetles

(both adults and larvae) (Flegg & Glue 1975;Durman 1977; Poxton 1986; Appleyard 1994;Tyler & Green 1994; Arthur & White 2001;Burfield 2002a; Sim et al. 2008).

Between July and September, when adultsundergo a complete post-breeding moult,and juveniles a partial moult, before theymigrate, the diet is dominated by berries suchas Bilberry Vaccinium myrtillus, CrowberryEmpetrum nigrum and Rowan Sorbus aucu-paria (Cramp 1988). Most British breedershave departed by late September, and reachthe wintering grounds from mid Octoberonwards. Winter diet is apparently domi-nated by Juniper berries, especially those ofPrickly Juniper Juniperus oxycedrus andPhoenician Juniper J. phoenicea (Arthur et al.2000; Ellis 2003; Ryall & Briggs 2006),although Zamora (1990) confirmed thatarthropods supplement the diet in Spain. Thebirds return north from late February(Cramp 1988).

Breeding populations in Fennoscandiaand central and southern Europe are gener-ally considered to be stable, but comprehen-sive monitoring data are lacking in manyareas (Tucker & Heath 1994; Janiga & Poxton1997; BirdLife International 2004). However,in parts of Switzerland, recent range contrac-tion to higher altitudes has been recordedand this has been linked to warmer summers(Schmid et al. 1998; Mattes et al. 2005). Thistrend is predicted to continue, with aclimate-induced decrease in suitable habitatshifting the predicted range of the Ring

Ouzel by up to 440 mhigher by 2070 (von demBussche et al. 2008).

The British breedingpopulation of Ring Ouzelshas been in long-termdecline, however. In thenineteenth century thespecies was widespread,with breeding records asfar north as Orkney andperhaps as far south asSurrey, Kent and Essex(Holloway 1996). Thedecline appears to havebegun in the twentiethcentury, and Baxter &Rintoul (1953) reported


Sim et al.

118. Male Ring Ouzel Turdus torquatus, Cairngorms, May 2006.

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large decreases in parts of Scotland between1900 and 1950. A 27% reduction in theBritish breeding range was apparent betweenthe 1968–72 and 1988–91 national atlases(Sharrock 1976; Gibbons et al. 1993), andthese more recent losses of range were partic-ularly marked in Scotland and Wales. The firstnational survey, in 1999, estimated the UKpopulation at 6,157–7,549 pairs, with furtherrange contraction and a probable 58% declinein population size since 1988–91 (Wotton etal. 2002). This led to the Ring Ouzel beingRed-listed (owing to a decline of more than50% over 25 years), and made a priority Bio-diversity Action Plan species, in the UK(Gregory et al. 2002; www.ukbap.org.uk).

In this paper we first examine populationtrend data from a number of monitoringprojects from across the species’ Britishbreeding range (fig. 1) to determine itscurrent regional status, and whether there isevidence of any broad geographical variationin the observed trends. Second, we review theevidence for the causes of regional declines inBritain and identify priorities for futureresearch to enable effective conservationmeasures to be implemented.

Recent population trendsSurveys in the different study areas (fig. 1)were carried out mainly by members of theRing Ouzel Study Group (www.ringouzel.info), which promotes co-ordinated researchand monitoring of Ring Ouzels in Britain.This helped to ensure consistency in thesurvey methods used, with only minor varia-tions among the different study areas. Thus,in each year of coverage, each area was sur-veyed at least twice between mid April andthe end of June. This involved walking slowlythrough the study area, usually on transectsabout 200 m apart, recording the number ofterritorial pairs (based upon nest-buildingactivity, nests located, recently fledged young,pairs seen or territorial behaviour observedon more than one visit, and/or agitatedbehaviour consistent with an occupied nest).Surveys were not carried out during heavyrain or in strong winds.

In Glen Clunie, Glen Effock, Glen Esk, theNorth York Moors and the Forest ofBowland, surveys were carried out approxi-mately every two weeks, as part of more


The decline of the Ring Ouzel in Britain

Fig. 1. Location of Ring Ouzel Turdus torquatusstudy areas in Britain.

intensive studies of breeding biology. RingOuzel song was played regularly (to elicit aresponse from territorial males) in Wales andthe Northwest Highlands, to ensure compar-ability with the 1999 national survey (Wottonet al. 2002), which provided the baseline datain these areas. The different studies varied inthe frequency of coverage during the respec-tive study periods, ranging from some withannual (or near-annual) coverage to thoseproviding two ‘snapshots’ only. The periodcovered by different studies also varied,extending across 27 years in Dartmoor butonly six years in Glen Effock.

The survey results show that declines werewidespread and serious, with 13 of the 14study areas showing a reduction in numbers(figs. 2 & 3). This included 11 areas in whichthe decline exceeded 50% (over periods of7–27 years), and two in which the popula-tions declined to extinction.

Ring Ouzel numbers in ten tetrads (2 kmx 2 km squares) in the Northwest Highlandsdeclined by 70% during 1999–2007, and by


83% in Glen Callater during 1998–2007.Three hill ranges (Lammermuirs, Moorfootsand Pentlands) in southeast Scotland showeddeclines of around 50% during 1985–2006,and numbers in 26 tetrads in Wales declinedby 69% during 1999–2006. The Exmoor pop-ulation declined from 13 pairs in 1993 toextinction in 2003–05, and numbers on Dart-moor fell by 63% during 1979–2006 (fig. 2).

The Glen Clunie population declined by67% during 1999–2009. In Glen Esk numbersfell by 41% during 1992–2009, but in theneighbouring Glen Effock they increased by88% during 2002–08. There was a populationdecline of 44% in Rosedale, North YorkMoors, during 2002–09, and the Long Myndpopulation declined from 16 pairs in 1995 toextinction in 2004–09. Finally, in the Forestof Bowland, numbers declined by 68%during 1995–2009 (fig. 3).

We compared the proportional declinebetween the Scottish Highlands (Northwest

Highlands, Glen Clunie, Glen Callater, GlenEsk and Glen Effock), southeast Scotland andnorthern England combined (Lammermuirs,Moorfoots, Pentlands, Forest of Bowland andNorth York Moors) and more southwestlocations (Dartmoor, Exmoor, Long Myndand Wales). However, there was no evidencefor any significant geographical variation(F2,9 = 0.39, P = 0.68).

The reasons for the population increase inGlen Effock are unknown, but may be linkedto a recent rise in sheep grazing, which hasincreased the area of short grass (M. Nicollpers. obs.), the favoured foraging habitat forRing Ouzels during the nestling period (Bur-field 2002a). Continued monitoring to deter-mine future trends at Glen Effock, togetherwith studies to identify the respective roles ofsurvival, breeding success and immigrationof breeding birds, is vital. Site-specific factorsmay also influence trends at some of theother study areas. For example, decreases in

sheep grazing havebeen noted in GlenEsk (with anexpected reductionin areas of shortgrass), while thedecline to extinc-tion of the smalland isolated LongMynd populationwas associatedwith increased nestpredation (Smith2006). However,the widespreadand near-consis-tent steep declinesthat have beenrecorded in mostareas stronglysuggest that large-scale factors areaffecting theBritish Ring Ouzelpopulation anddriving theobserved nationalpopulation decline.


Sim et al.

1975 1980 1985 1990 1995 2000 2005 2010

Fig. 2. Trends in Ring Ouzel Turdus torquatus numbers in Britain fromperiodic repeat surveys.

90

80

70

60

50

40

30

20

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Glen Callater

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1990 1994 1998 2002 2006 2010

Fig. 3. Trends in Ring Ouzel Turdus torquatus numbers from study areas inBritain surveyed regularly in recent years. Broken lines indicate missing datafrom some years.

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25

20

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Research into causes of declinesA number of possible causes have been sug-gested to explain the decline of the BritishRing Ouzel population but, until recently,little evidence has been available to assesswhich of these may be relevant, and at whichstage of the life-cycle they may be operating.However, over the last decade a number ofdetailed studies have added considerably toour knowledge of Ring Ouzel ecology, habitatrequirements and population dynamics.

Two studies have examined factors associ-ated with declines in breeding abundance, orthe desertion of historically occupiedbreeding sites. First, analyses of data fromacross Scotland found that Ring Ouzels hadcontracted to steeper areas within an altitu-dinal range of 350–750 m, and away fromconiferous forests and any associated poten-tial impacts on adjacent moorlands (e.g.decreased grazing pressure on adjacent openground, increased numbers of potentialpredators using the forests as cover and pop-ulation fragmentation; Buchanan et al. 2003).Second, long-term data on the occupation ofbreeding sites in the Moorfoot Hills, between1952–85 and 1998–2000, found that site

desertion was more likely at lower altitudesand where there was now lower Heathercover within both 200 m and 450 m offormer nesting sites (Sim et al. 2007). Inaddition, the currently occupied nesting sitesin the Moorfoots were more likely to haveHeather or a Heather/grass mosaic within100 m than were topographically suitable,but unoccupied, potential nesting sites.

Together, these studies show that RingOuzel breeding distribution has contractedto sites at higher altitudes, with greaterHeather cover and away from conifer planta-tions. They do not demonstrate whether suchrelationships are causal (for example,whether lower Heather cover around nestsaffects breeding success, or climate change iscausing low-altitude sites to become unsuit-able), or whether they simply reflect a con-traction to preferred areas as the populationdeclines because of other, unrelated, causes(such as reduced overwinter survival).However, declines have also been recorded inareas where Heather cover remains extensivearound nesting sites and where there hasbeen little or no afforestation (e.g. GlenClunie, Glen Esk and Glen Callater). Further-



119. A typical Ring Ouzel Turdus torquatus nest-site in Britain, this one being on a heather-coveredcrag in Glen Clunie in May 2008.

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more, detailed studies have found that nestsurvival rates and overall breeding success inthe Moorfoot Hills (an area with afforesta-tion and historical declines in Heather cover)were similar to those in other areas wherethere has been little change in these aspects ofthe habitat (e.g. Glen Esk and Glen Clunie;Burfield 2002a; Sim et al. in prep.). There-fore, while such land-use changes haveundoubtedly contributed to declines in someareas, they seem unlikely to be the majorfactor driving the overall declines.

Another study investigated climate corre-lates of Ring Ouzel breeding success andpopulation trends in northern Britain, toassess possible links between populationdecline and climate change (Beale et al.2006). Population declines in the MoorfootHills followed years when British summer(June–August) weather was warm and mod-erately wet, and when spring rainfall inMorocco 24 months previously was high(suppressing Juniper flowering, and thusreducing berry production, with possibleadverse consequences for subsequent over-winter survival of Ring Ouzels). Based uponthe recent trends in these three weather vari-ables, these relationships suggested thatincreases in British summer temperatures

may be driving Ring Ouzel populationdeclines, possibly through causing drier soilconditions, hence reducing earthworm avail-ability, at the end of the breeding season andduring the post-fledging period (Beale et al.2006).

However, preliminary findings fromstudies in 2007–08 on the foraging behaviourand survival of radio-tagged Ring Ouzelfledglings at Glen Clunie (Sim et al. in prep.)provide little evidence for unusually low sur-vival during the post-fledging period. Indeed,Ring Ouzel survival rates there appear tocompare favourably with those of similar-sized passerines in Britain and the USA(Anders et al. 1997; Robinson et al. 2004;White et al. 2005; King et al. 2006; Schmidt etal. 2008). In addition, there was no evidencefor any seasonal decline in either earthwormabundance or soil moisture levels, although2007 was a very wet year and 2008 a fairly dryone. However, this study covered only twosummers, and a longer run of data would berequired to assess how local, national andglobal climatic variables may influence localRing Ouzel productivity and survival.

Long-term studies of breeding success andsurvival rates in declining populations canprovide valuable insights into, and under-


Sim et al.

120. Brood of four Ring Ouzels Turdus torquatus in a nest in Glen Clunie, July 2009.

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standing of, the causes of decline. Such workhas been undertaken in a joint GrampianRinging Group/RSPB project on Ring Ouzelsin Glen Clunie during 1998–2009. This glenwas known to hold a relatively high-densitypopulation that was stable between 1991 and1998 (Rebecca 2001), but which subsequentlydeclined markedly during 1998–2009 (fig. 3).Over this period, changes in some aspects ofbreeding success have been detected (e.g.reduced mean brood size of first nests atfledging, from 3.8 to 3.4, owing to decreasednestling survival). However, this effect hasbeen offset by a small increase in nest sur-vival rate, so that there has been no decline inoverall reproductive success (Sim et al. inprep.).

Preliminary analyses of adult survival ofRing Ouzels in Glen Clunie suggest that itwas low compared with similar species inBritain and North America (Savidge & Davis1974; Nichols et al. 1981; Roth & Johnson1993; Siriwardena et al. 1998; Porneluzi &Faaborg 1999; Bayne & Hobson 2002; Gardaliet al. 2003). Although adult Ring Ouzel sur-vival did not decline during the course of thestudy, return rates of first-year birds diddecline, though whether this reflected highermortality, higher dispersal away from the

natal areas, or both, is unknown. Since adultsurvival appears to be low compared withsimilar species, and given that populationmodelling (elasticity analysis) indicates thatpopulation growth rate is particularly sensi-tive to variation in first-year survival, thissuggests that low survival may be a key driverof Ring Ouzel declines (Sim et al. in prep.). Itis therefore important to identify the causesof poor survival.

As a migrant, the Ring Ouzel is affected byfactors acting on the breeding grounds, inoverwintering areas and during migration,and this adds to the difficulties of identifyingthe causes of low survival. An analysis of thenumber of Ring Ouzel bird-days at Britishand Irish bird observatories in spring during1970–98 found that numbers passingthrough western observatories (assumed tobe mainly British breeding birds) declinedsignificantly, whereas numbers passingthrough east-coast observatories (assumed tobe mainly Fennoscandian breeders) did not(Burfield & Brooke 2005). If these assump-tions are correct, this suggests that the causesof low survival could occur on the breedinggrounds or on migration, because British andFennoscandian birds have overlapping win-tering ranges (Burfield 2002b); individuals of



121. Wintering habitat for British Ring Ouzels Turdus torquatus: the juniper-clad slopes of the AtlasMountains in Morocco.

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both subspecies have been trapped at thesame time and in the same nets in Morocco(Ellis 2003).

The expected difference in migrationroute and timings of the two populationscould expose them to different risks. In par-ticular, although hunting of other thrushspecies is permitted under the Birds Directivein certain EU countries, particularly in theMediterranean, the Ring Ouzel is not a legalquarry in any member state (OJEU 2010).However, there is a real risk that Ring Ouzelsmay be confused with other thrushes byhunters and shot in error. In general, thehunting season in France ends on 10th Feb-ruary but a number of species (includingthrushes) may be legally hunted in somesouthern departments until 20th February(JORF 2009). Consequently, British-breedingRing Ouzels passing through France earlier

than Fennoscandian breeders in spring maybe exposed to greater mortality risks fromhunting. Furthermore, in autumn, Britishbreeders probably migrate through France ona more westerly route than Fennoscandianbreeders and are more likely to pass throughsouthwest France, where ringing recoveriesshow that hunting pressure is particularlyintense (Burfield 2001).

Few studies of Ring Ouzels have beenundertaken in their wintering areas, but insouthern Spain the berries of Common J.communis and Phoenician Juniper were themost frequent food items (Zamora 1990;Jordano 1993). However, in Morocco’s AtlasMountains, Phoenician (and to a lesserextent Prickly) Juniper berries were consid-ered the most frequent food items (Arthur etal. 2000; Ellis 2003). Ryall & Briggs (2006)confirmed this preference for Phoenician

Juniper, and noted that theJuniper woodlands used byRing Ouzels were in adegraded and ageing state.Damage to trees fromcutting, indicative ofgeneral levels of distur-bance, appeared to be astronger determinant ofRing Ouzel presence thandid the number of berries(Ryall & Briggs 2006). Inaddition, Beale et al.(2006) provided some evi-dence that food availabilityin the wintering areas mayaffect survival, linkingpopulation declines in theMoorfoot Hills to levels ofrainfall in the winteringareas (and hence Juniperberry abundance – seeabove).

Future researchprioritiesResearch to date has iden-tified a number of factorsthat may be involved incausing the decline of theBritish Ring Ouzel popula-tion, but suggests that lowfirst-year, and possibly


Sim et al.

122. Male Ring Ouzel Turdus torquatus, Cairngorms, May 2006.

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adult, survival may be the critical demo-graphic parameter driving this decline. Thecauses of low survival and whether these areoperating on the breeding or winteringgrounds, or on migration routes, remainunknown. Research that examines the factorsaffecting survival at all of these stages of thelife-cycle is now urgently required. Designingand undertaking studies that measure sur-vival during each of these stages, and whichidentify the main causes of mortality, repre-sents a major challenge. However, recentadvances in the miniaturisation of trackingdevices, most notably geolocators (Fiedler2009), mean that it is now possible to trackbirds the size of a Ring Ouzel through the fullannual cycle, and this increases the feasibilityof identifying the timing of migration andthe location of the main stopover and win-tering sites.

Further work should also be encouragedon the British breeding grounds, to testexperimentally the effect of habitat and man-agement manipulations on breeding successand survival. Effective monitoring of theBritish breeding population remains chal-lenging, with coverage by the Breeding BirdSurvey (BBS) being inadequate to detectnational trends. Recent increases in BBS cov-erage within the English uplands will help toimprove this situation considerably, but themajority of the British population willremain poorly covered. However, the secondnational Ring Ouzel survey, scheduled for2011, should provide information onnational and regional population trends, andthe results of the 2007–11 Atlas will shedlight on changes in distribution.

Outside Britain, further studies of RingOuzel ecology in the wintering areas wouldbe valuable. Studies to establish the full win-tering range of the British breeding popula-tion, and the extent and drivers (e.g.agriculture, development, drought, demandfor firewood) of change in Juniper wood-lands within this area will help to determinewhether winter food supplies may be a crit-ical issue. Determining whether largenumbers of British birds are being killed onmigration through France and Spain wouldsimilarly provide initial indications as to therole of hunting mortality. Finally, there is aneed to improve our knowledge of trends

and, where relevant, the causes of declines inother European breeding populations. Manyof these are very poorly studied and the trenddata available are qualitative or semi-quanti-tative at best (Tucker & Heath 1994; Janiga &Poxton 1997; BirdLife International 2004).Priority countries for improved monitoringshould include those with the largest popula-tions (e.g. Romania, Austria, Norway andRussia) and those at the southern limit of therange and thus most vulnerable to climatechange (e.g. Spain, Italy and Turkey).

Acknowledgments

We thank the members of the Ring Ouzel StudyGroup who contributed to the regional studies andlandowners and tenants for co-operation with access.The Glen Clunie study was funded by RSPB, theScottish Ornithologists’ Club, Scottish Natural Heritageand the Cairngorms National Park Authority. Surveyson Dartmoor and Exmoor were funded by Dartmoorand Exmoor National Park Authorities, NaturalEngland and Defence Estates. Ian Burfield, MurrayGrant and Jeremy Wilson provided valuable commentson earlier drafts of the paper.

References

Anders,A. D., Dearborn, D. C., Faaborg, J., & Thompson,F. R. 1997. Juvenile survival in a population ofneotropical migrant birds. Cons. Biol. 11: 698–707.

Appleyard, I. 1994. Ring Ouzels of the Yorkshire Dales.Maney, Leeds.

Arthur, D. S. C., & White, S. A. 2001. Numbers,distribution and breeding biology of Ring Ouzels inupper Glen Esk, 1992–98. Scott. Birds 22: 50–59.

—, Ellis, P. R., Lawie, R. G., & Nicoll, M. 2000.Observations of wintering Ring Ouzels and theirhabitat in the High Atlas Mountains, Morocco.Scott. Birds 21: 109–115.

Baxter, E.V., & Rintoul, L. J. 1953. The Birds of Scotland.Oliver & Boyd, Edinburgh.

Bayne, E. M., & Hobson, K. A. 2002. Annual survival ofadult American Redstarts and Ovenbirds in thesouthern Boreal forest. Wilson Bull. 114: 358–367.

Beale, C. M., Burfield, I. J., Sim, I. M.W., Rebecca, G.W.,Pearce-Higgins, J.W., & Grant, M. C. 2006. Climatechange may account for the decline in British RingOuzels Turdus torquatus. J. Anim. Ecol. 75: 826–835.

BirdLife International 2004. Birds in Europe: populationestimates, trends and conservation status. BirdLifeInternational (Conservation Series No. 12),Cambridge.

Buchanan, G. M., Pearce-Higgins, J.W., Grant, M. C., &Whitfield, P. 2003. Correlates of the change in RingOuzel Turdus torquatus abundance in Scotland from1988–91 to 1999. Bird Study 50: 97–105.

Burfield, I. J. 2001. Ringed ouzels: where do they go inwinter? Ringers’ Bull. 10: 58.

— 2002a.The breeding ecology and conservation ofthe Ring Ouzel Turdus torquatus in Britain.Unpublished PhD thesis. University of Cambridge.

— 2002b.The Ring Ouzel. In:Wernham, C.V.,Toms,M. P., Marchant, J. H., Clark, J. A., Siriwardena, G. M., &




Baillie, S. R. (eds.), The Migration Atlas: movements ofthe birds of Britain & Ireland. Poyser, London.

— & Brooke, M. de L. 2005.The decline of the RingOuzel Turdus torquatus in Britain: evidence from birdobservatory data. Ringing & Migration 22: 199–204.

Cramp, S. (ed.) 1988. The Birds of the WesternPalearctic. Vol. 5. OUP, Oxford.

Durman, R. F. 1977. Ring Ouzels in the Pentlands.Edinburgh Ringing Group Report 5: 24–27.

Ellis, P. 2003. Ringing Ring Ouzels Turdus torquatus inMorocco.Tay Ringing Group Report 2001–03:32–40.

Fiedler,W. 2009. New technologies for monitoring birdmigration and behaviour. Ringing & Migration 24:175–179.

Flegg, J. J. M., & Glue, D. E. 1975.The nesting of theRing Ousel. Bird Study 22: 1–8.

Gardali,T., Barton, D. C.,White, J. D., & Geupel, G.2003. Juvenile and adult survival of Swainson’sThrush (Catharus ustulatus) in coastal California:annual estimates using capture-recapture analyses.Auk 120: 1188–1194.

Gibbons, D.W., Reid, J. B., & Chapman, R. A. 1993.The New Atlas of Breeding Birds in Britain and Ireland:1988–1991. Poyser, London.

Gregory, R. D.,Wilkinson, N. I., Noble, D. G., Robinson,J. A., Brown, A. F., Hughes, J., Procter, D. A., Gibbons,D.W., & Galbraith, C. A. 2002.The population statusof birds in the United Kingdom, Channel Islands andIsle of Man: an analysis of conservation concern2002–2007. Brit. Birds 95: 410–450.

Holloway, S. 1996. The Historical Atlas of Breeding Birdsin Britain and Ireland: 1875–1900. Poyser, London.

Janiga, M., & Poxton, I. R. 1997.The Ring Ouzel. In:Hagemeijer,W. J. M., & Blair, M. J. (eds.), The EBCCAtlas of European Breeding Birds. Poyser, London.

Jordano, P. 1993. Geographical ecology and variation ofplant-seed disperser interactions: southern Spanishjunipers and frugivorous thrushes. Vegetation107–108: 85–104.

JORF 2009. Arrêté du 19 janvier 2009 relatif aux datesde fermeture de la chasse aux oiseaux de passageet au gibier d’eau, hormis les limicoles et les oies.Journal officiel de la République française 17 (21 January 2009): 1321.www.legifrance.gouv.fr/affichTexte.do;jsessionid=FA9986F2437D0FC956C4C7EF3AEEF1C5.tpdjo09v_1?cidTexte=JORFTEXT000020128976&categorieLien=id

King, D. I., Degraaf, R. M., Smith, M-L., & Buonaccorsi,J. P. 2006. Habitat selection and habitat-specificsurvival of fledgling Ovenbirds (Seiurus aurocapilla).J. Zool. 269: 414–421.

Mattes, H., Maurizio, R., & Burkli,W. 2005. Die Vogelweltim Oberengadin, Bergell und Puschlav. SchweizerischeVogelwarte, Sempach.

Nichols, J. D., Noon, B. R., Stokes, S. L., & Hines, J. E.1981. Remarks on the use of mark-recapturemethodology in estimating avian population size.Studies in Avian Biology 6: 121–136.

OJEU 2010. EC Directive 2009/147/EC of theEuropean Parliament and of the Council of 30November 2009 on the conservation of wild birds(codified version). Official Journal of the EuropeanUnion L 20 (26 January 2010): 7–25.http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:020:0007:0025:EN:PDF

Porneluzi, P. A., & Faaborg, J. 1999. Season-longfecundity, survival, and viability of Ovenbirds infragmented and unfragmented landscapes.Cons. Biol. 13: 1151–1161.

Poxton, I. R. 1986. Breeding Ring Ouzels in thePentland Hills. Scott. Birds 14: 44–48.

Rebecca, G.W. 2001.The contrasting status of theRing Ouzel in two areas of upper Deeside, northeast Scotland, between 1991 and 1998. Scott. Birds22: 9–19.

Robinson, R. A., Green, R. E., Baillie, S. R., Peach,W. J., &Thomson, D. L. 2004. Demographic mechanisms ofthe population decline of the Song Thrush Turdusphilomelos in Britain. J. Anim. Ecol. 73: 670–682.

Rollie, C. 1997.The Ring Ouzel. In: Forrester, R.W.,Andrews, I. J., McInerny, C. J., Murray, R. D.,McGowan, R.Y., Zonfrillo, B., Betts, M.W., Jardine,D. C., & Grundy, D. S. (eds.), The Birds of Scotland.SOC, Aberlady.

Roth, R. R., & Johnson, R. K. 1993. Long-term dynamicsof a Wood Thrush population breeding in a forestfragment. Auk 110: 37–48.

Ryall, C., & Briggs, K. 2006. Some factors affectingforaging and habitat of Ring Ouzels Turdus torquatuswintering in the Atlas Mountains of Morocco.Bull. African Bird Club 13: 17–31.

Savidge, I. R., & Davis, D. E. 1974. Survival of somecommon passerines in a Pennsylvania woodlot.Bird-Banding 45: 152–155.

Schmid, H., Luder, R., Naef-Daenzer, B., Graf, R., &Zbinden, N. 1998. Schweizer Brutvogelatlas.Verbreitung der Brutvögel in der Schweiz und imFürstentum Liechtenstein 1993–1996. SchweizerischeVogelwarte, Sempach.

Schmidt, K. A., Rush, S. A., & Ostfeld, R. S. 2008.WoodThrush nest success and post-fledging survivalacross a temporal pulse of small mammalabundance in an oak forest. J. Anim. Ecol. 77:830–837.

Sharrock, J.T. R. (ed.) 1976. The Atlas of Breeding Birdsin Britain & Ireland. Poyser, Calton.

Sim, I. M.W., Rebecca, G.W., & Ludwig, S. C. 2008.Glen Clunie Ring Ouzel Breeding Ecology Project.North-East Scotland Bird Report 2006: 117–119.

—, —, —, Grant, M. C., & Reid, J. M. (In prep.).Characterising demographic variation andcontributions to population growth rate in a small,declining Ring Ouzel Turdus torquatus population.

—, Burfield, I. J., Grant, M. C., Pearce-Higgins, J.W., &Brooke, M. de L. 2007.The role of habitatcomposition in determining breeding siteoccupancy in a declining Ring Ouzel Turdustorquatus population. Ibis 149: 374–385.

Siriwardena, G. M., Baillie, S. R., & Wilson, J. D. 1998.Variation in the survival rates of some Britishpasserines with respect to their population trendson farmland. Bird Study 45: 276–292.

Smith, L. 2006. Shropshire Biodiversity Action Plan forRing Ouzel. Shropshire Biodiversity Partnership.

Tucker, G. M., & Heath, M. F. 1994. Birds in Europe: theirconservation status. BirdLife International(Conservation Series No. 3), Cambridge.

Tyler, S. J., & Green, M. 1994.The status and breedingecology of Ring Ouzels Turdus torquatus in Wales with reference to soil acidity.Welsh Bird Report 7: 78–79.

von dem Bussche, J., Spaar, R., Schmid, H., & Schroder,


Sim et al.


B. 2008. Modelling the recent and future spatialdistribution of the Ring Ouzel (Turdus torquatus)and Blackbird (T. merula) in Switzerland.J. Ornithol. 149: 529–544.

White, J. D., Gardali,T.,Thompson, F. R., & Faaborg, J.2005. Resource selection by juvenile Swainson’sThrushes during the postfledging period.

Condor 107: 388–401.Wotton, S. R., Langston, R. H., & Gregory, R. D. 2002.

The breeding status of the Ring Ouzel Turdustorquatus in the UK in 1999. Bird Study 49: 26–34.

Zamora, R. 1990.The fruit diet of Ring Ouzels (Turdustorquatus) wintering in the Sierra Nevada.Alauda 58: 67–70.



Innes Sim, RSPB Scotland, Dunedin House, 25 Ravelston Terrace, Edinburgh EH4 3TPChris Rollie, RSPB Scotland, The Old School, Crossmichael, Castle Douglas DG7 3UWDavid Arthur, Panmure Cottage, 1 Tennis Road, Carnoustie DD7 6HHStuart Benn, RSPB Scotland, Etive House, Beechwood Park, Inverness IV2 3BWHelen Booker, RSPB, Keble House, Southernhay Gardens, Exeter EX1 1NTVic Fairbrother, 8 Whitby Avenue, Guisborough, Cleveland TS14 7APMick Green, Ecology Matters Ltd, Bronhaul, Pentrebach, Talybont SY24 5EHKen Hutchinson, White Gate Cottage, Church Lane, Thornton le Dale, North Yorkshire YO18 7QLSonja Ludwig, c/o RSPB Scotland, Dunedin House, 25 Ravelston Terrace, Edinburgh EH4 3TPMike Nicoll, Dundee Museum, Dundee, Tayside DD1 1DAIan Poxton, 217 Newbattle Abbey Crescent, Dalkeith, Midlothian EH22 3LUGraham Rebecca, RSPB Scotland, 10 Albyn Terrace, Aberdeen AB10 1YPLeo Smith, 8 Welsh Street Gardens, Bishops Castle, Shropshire SY9 5BHAndrew Stanbury, RSPB, The Lodge, Sandy, Bedfordshire SG19 2DLPete Wilson, RSPB, United Utilities Bowland Estate Office, Stocks Boardhouse, Slaidburn, Clitheroe,

Lancashire BB7 3AQ

Atlas 2007–11 updateAt the halfway stage of breeding-season fieldwork for Bird Atlas2007–11, a provisional map showingthe distribution of the Ring Ouzel isavailable. The level of breeding evi-dence recorded so far is shown by thesize of the dot, which indicates pos-sible (small), probable (medium) andconfirmed (large) breeding. Field-work in April–July 2008 and 2009covered much of the core range of theRing Ouzel, although some remote ordifficult-to-access 10-km squares maynot have been visited yet. Comparedwith the 1988–91 Breeding Atlas, theprovisional map suggests furtherrange contraction across all breedingareas in Britain & Ireland. If you haveany records from 2008 or 2009 notshown here, please submit them assoon as possible. Fieldwork for thethird breeding season started on 1stApril and all records of Ring Ouzelsin breeding habitat are welcomed.Records can be submitted online atwww.birdatlas.net or by requestingpaper forms from the BTO (tel. 01842750050).


I very much enjoyed Tim Melling’s thoroughpaper on the Eskimo Curlew Numenius bore-alis in Britain (Brit. Birds 103: 80–92).However, I would like to comment on twoparticular issues raised in the article.

Firstly, I was surprised by the repeatedassertion that Audubon saw the EskimoCurlew only once, off South Carolina. In fact,he saw the species on many occasions and inconsiderable numbers. On 6th June 1833,Audubon and five companions left Eastport,Maine, on the schooner Ripley, spending thesummer in Labrador and returning on 31stAugust. The expedition’s highlights were thediscovery of Lincoln’s Sparrow Melospiza lin-colnii and the recording of large numbers ofEskimo Curlews (Townsend 1918). In theOrnithological Biography (Audubon1831–1839) which accompanied Audubon’smonumental Birds of America, there is a thor-ough first-hand account of these observa-tions. The following is but a brief extract:

‘On the 29th of July, 1833, during a thickfog, the Esquimaux Curlews made their firstappearance in Labrador, near the harbour ofBrag d’Or. They evidently came from thenorth, and arrived in such dense flocks as toremind me of the Passenger Pigeons… Formore than a week we had been looking forthem, as was every fisherman in the harbour,these birds being considered there, as indeedthey are, great delicacies. The birds at lengthcame, flock after flock, passed close round ourvessel, and directed their course toward thesterile mountainous tracts in the neighbour-hood; and as soon as the sun’s rays haddispersed the fogs that hung over the land, ourwhole party went off in search of them.

‘I was not long in discovering that their stayon this coast was occasioned solely by thedensity of the mists and the heavy gales that

already gave intimation of the approachingclose of the summer; for whenever the weathercleared up a little, thousands of them set offand steered in a straight course across thebroad Gulf of St Lawrence. On the contrary,when the wind was high, and the fogs thick,they flew swiftly and low over the rocky surfaceof the country, as if bewildered. Wherever therewas a spot that seemed likely to afford a supplyof food, there the Curlews abounded, and wereeasily approached. By the 12th of August,however, they had all left the country.’

Secondly, the paper refers to the sweepingchanges overtaking the American prairies asan additional factor in the demise of theEskimo Curlew. Changes to grazing andburning regimes and the extinction of theRocky Mountain Locust Melanopus spretusare rightly highlighted but perhaps the mostimportant factor in the transformation of thegrassland ecosystem was ploughing. TheEskimo Curlews favoured the tallgrass prairiezone of eastern Oklahoma, Kansas andNebraska and western Missouri and Iowa(Johnsgard 1980) but by 1870 the settlementfrontier had already crossed these rich grass-lands and reached as far west as the 98thmeridian, the threshold of more aridcountry. Equipped with John Deere’s newsteel plough, settlers tore up the sod withenthusiasm and by 1890 most of the easterntallgrass was gone (Webb 1931).

References

Audubon, J. J. 1831–1839. Ornithological Biography.Black, Edinburgh.

Johnsgard, P.A. 1980. Where Have All the Curlews Gone?University of Nebraska, Lincoln.http://digitalcommons.unl.edu/biosciornithology/23

Townsend, C.W. 1918. In Audubon’s Labrador.Houghton Mifflin, Boston.

Webb,W. P. 1931. The Great Plains. Grosset & Dunlap,New York.


LettersEskimo Curlews

Recent papers on the Eagle Owl Bubo bubo(Brit. Wildlife 20: 405–412; Brit. Birds 101:478–490; see also pp. 213–222) have dis-

cussed the provenance of birds recorded inBritain and the likelihood of the speciesoccurring naturally. I recall that the West

Andy Stoddart, 7 Elsden Close, Holt, Norfolk NR25 6JW

Eagle Owls in Britain


Midlands bird on 9th December 1990 wasfound at the time of the BTO Annual confer-ence at Swanwick, Derbyshire, during whichthere were blizzards. At the time, MikeRogers asked me to look at the possibility ofthis bird being a genuine vagrant. My tenta-tive investigation suggested that it could havebeen carried from southwest Norway on thenortheasterlies of the depression bringing thesnow. This opinion was forwarded to MR butthe individual was finally presumed to be anescape.

The recent papers reminded me of thisevent and I have taken the opportunity ofresearching the air-mass trajectories for thisperiod using the latest computer model tech-niques developed by NOAA, which supportmy earlier deduction. The depression inquestion deepened over eastern Englandduring 8th December, subsequently drifting

SSW and filling during the next 24 hours.The northeast winds on its northern flankwere strongest during that day and coveredthe whole of the northern North Sea. The airarriving in the Midlands late on 8thDecember originated in Rogaland, Norway,less than 16 hours previously. The low-levelwind speed added to a notional 35-kph flightspeed indicated a ground speed of 100 kphand therefore the duration of the seaward legof any crossing could have been as little asseven hours. The very strong northeasterlywinds, dense cloud and heavy precipitationthat covered most of northeast Englandcould conceivably have led to the bird over-shooting the east coast by such a margin.

Although the owl’s exact provenance willnever be known, it may just be the best candidate yet for a genuine vagrant EagleOwl.

Letters


In 1981, an editorial in BB entitled ‘Birdtopography’ (Brit. Birds 74: 239–242) set outto standardise the somewhat inconsistentapproach to bird topography that had existedin bird books and field guides up to thatpoint. Special mention was made of the dif-fering names given to the various stripes onthe lower part of the head of some passer-ines, such as pipits Anthus and buntingsEmberiza. The editorial recommended thatthey should be named, from top to bottom:(1) the ‘moustachial stripe’, (2) the ‘submous-tachial stripe’ and (3) the ‘malar stripe’. Thisterminology has since been adopted by allauthoritative books and journals, such asSvensson (1992) and Svensson et al. (1999),as well as BWP. It remained in use until, in apaper entitled ‘What is the malar?’, Sibley(2001) suggested some amendments to theseterms. In particular, he correctly pointed outthat the malar stripe is not actually on thegroup of feathers known as the ‘malar’. Thislower stripe in fact runs down the outer edgeof the throat feathers and, as a consequence,Sibley recommended that it be renamed the‘lateral throat-stripe’, a term that has, inci-dentally, long been used in Sweden. Anotheradvantage of this change was that, in Britain,there has often been a certain amount of

confusion over the term ‘malar stripe’.Sibley also pointed out that what we call

the ‘submoustachial stripe’ is actually on thegroup of feathers known as the ‘malar’. Hesuggested, therefore, that the term ‘submous-tachial stripe’ be abandoned and that the palestripe that is often present in this area shouldbe simply renamed the ‘malar’, reflecting thegroup of feathers that it largely follows. Sucha move would have the added benefit ofbringing Europeans into line with NorthAmericans, who have historically referred tothis pale stripe as the ‘malar’.

Since there seemed to be no opposition toSibley’s 2001 recommendations, Vinicombe(2007) followed this new terminology in anarticle on topography in Birdwatch. Subse-quently, LS contacted KEV to question thewisdom of replacing the term ‘submous-tachial stripe’ with the ‘malar’. He was con-cerned about two problems in particular.Firstly, on the skull of an animal the malaractually relates to the upper cheek bone,whereas the feather group in question iscloser to the bone of the lower mandible.More importantly, if the former ‘malar stripe’is changed to the ‘lateral throat-stripe’ andthe former ‘submoustachial stripe’ is in turnrenamed the ‘malar’, this would introduce an

Norman Elkins, 18 Scotstarvit View, Cupar, Fife KY15 5DX

The malar stripe


unnecessary complication that providesanother significant source of confusion.Given that the use of the term ‘malar’ hasalways been confusing, LS considered it likelythat it would become even more so if it wastransferred to a different plumage feature. Hecould see no objection to the retention of theterm ‘submoustachial stripe’, particularlysince (1) it describes the mark perfectly and(2) its retention would then necessitate onlyone change instead of two (i.e. simplychanging the traditional ‘malar stripe’ to the‘lateral throat-stripe’).

This thought had also occurred to KEV, sowe approached David Sibley for his views onthe subject. In his response, he stressed thepoint that plumage features do not alwaysrelate precisely to the feather groups thatunderlie them. In many ways, this warrantstwo sets of terminology: one to preciselydescribe the feather groups themselves andanother, less precise terminology to enablebirders to describe plumage markings.

Sibley agreed, however, that the use of theterm ‘malar’ has been and remains confusingand inappropriate – particularly in Europe –and he considers that there is an argumentfor ‘retiring’ it completely. The problem,though, is that the ‘malar’ has been tradition-ally used in North America for at least 100


Letters

Lars Svensson, S:ta Toras väg 28, S-260 93 Torekov, SwedenKeith E. Vinicombe, Bristol

years. As a conse-quence, he didnot feel able torecommend theintroduction of‘submoustachialstripe’ in NorthAmerica, wherethat particularterm has neverbeen widely used.

The simplestoption would beto accept that theNorth Americanand Europeanterminologies aredifferent. There is nothing toprevent the Euro-

peans from continuing to refer to the palemiddle stripe as the ‘submoustachial stripe’, aterm that describes the feature both accu-rately and clearly. Although transatlantic uni-formity would be desirable, there are alreadyother differences in plumage terminologies,examples being the ‘supercilium’, which theNorth Americans call the ‘eyebrow’, and the‘ear-coverts’, which they call either the ‘cheek’or the ‘auriculars’. Furthermore, the Ameri-cans often refer to the wing-bend area as the‘shoulder’. It would be similarly unwise anddifficult to propose the introduction of anyof these American terms in Europe.

For the sake of simplicity, therefore, werecommend that in Europe the term ‘sub-moustachial stripe’ is retained for the palestripe between the ‘moustachial stripe’ aboveit and the newly named ‘lateral throat-stripe’below it (see plate 123). In North Americathe ‘malar’ will continue to be used for thismark.

References

Sibley, D. 2001. ‘What is the malar?’ Brit. Birds 94: 80–84.Svensson, L. 1992. Identification Guide to European

Passerines. 4th edn. Privately published, Stockholm.—, Grant, P. J., Mullarney, K., & Zetterström, D. 1999.

Collins Bird Guide. HarperCollins, London.Vinicombe, K. 2007. ‘Topographical tips’. Birdwatch 176:

28–31.

123. The moustachial and submoustachial stripes and lateral throat-stripe on aRustic Bunting Emberiza rustica (Finland, June 2005).

Mar

kus V

ares

vuo

moustachial

submoustachial

lateralthroat-stripe


On 17th December 2008, at Calvert landfill,Buckinghamshire, I watched two Red KitesMilvus milvus in the air, seemingly playing agame of catch. The higher bird threw a smallobject upwards and sideways a distance ofabout 3 m by spinning around in the airrather like a discus thrower. As the object fell,the lower bird caught it in a talon. The birds

then tumbled about for a few seconds beforethe bird with the object threw it back to theother bird using the same technique. Theyflew off into the distance, tumbling, but Ididn’t see them making any more throws.This was not the usual food-passing ofraptors, which is, I believe, more of a simpledrop.


NotesRed Kites playing catch?

In 2007, I made several visits to a locality inthe Derwent Valley, Derbyshire, to monitorthe breeding attempts of a pair of NorthernGoshawks Accipiter gentilis. Between May andJuly, three singing male Firecrests Regulusignicapilla were also observed at this locality,all within 20 m of the Goshawk nest. Unfor-tunately, the young Goshawks disappearedwhen they were about seven days old, but Icontinued to visit the area to follow the for-tunes of the Firecrests. No young were seenbut a first-year male and female Firecrestwere ringed there in September.

In 2008, the breeding Goshawks nestedabout 1 km from the 2007 site. Theirbreeding cycle progressed well, aided by araptor nestwatch scheme. Many unsuccessfulattempts were made to find Firecrests at theprevious year’s site, but four singing maleswere recorded within 30 m of the newGoshawk nest during May, June and July. Thetwo localities had similar habitat structure,predominantly European Larch Larix deciduaand Sitka Spruce Picea sitchensis, as did muchof the general area, and there were noobvious differences, either in habitat orwoodland management, between the sites.

Four Goshawk chicks were ringed by theSorby Breck Ringing Group (SBRG) on 23rdMay but on 29th May, after heavy rain andgales, the nest and four young were found onthe ground. Emergency action was taken byJack Street (SBRG) and Dave Jones (ForestEnterprise) to erect an artificial nest plat-form, on which the three surviving young

were placed, two of which eventually fledged.Proof of breeding by one pair of Firecrestswas obtained on 15th July, when they wereseen feeding recently fledged young less than10 m from the recently vacated Goshawknest.

CCTV footage of the Goshawk nestduring this period showed that around 95%of the prey items were Grey Squirrels Sciuruscarolinensis; other prey included EurasianSparrowhawk Accipiter nisus, Eurasian JayGarrulus glandarius and Great SpottedWoodpecker Dendrocopos major. All of theseare potential predators of Firecrests and itseemed plausible that the Firecrests hadselectively chosen their breeding site to beclose to the Goshawks, especially sincesearches of apparently suitable habitat else-where in the area failed to find any Firecrests.

In 2009, only a single male Goshawk waspresent at the 2008 site, with none at the2007 site. Three singing male Firecrests werefound in May, June and July, but, without aGoshawk nest as a focus, were more difficultto locate along the small woodland valley.Their response to playback tapes of theirsong was shorter and much more intermit-tent than in 2008.

Symbiotic relationships between raptorsand other species have certainly beenrecorded before and perhaps the best-knownexample is that of Peregrine Falcons Falcoperegrinus and Red-breasted Geese Brantaruficollis in Arctic Russia. In addition, Blanco& Tella (1992) reported a protective

David Ferguson, 21 Amersham Road, Beaconsfield, Buckinghamshire HP9 2HA

Apparent nesting association of Northern Goshawks andFirecrests


association and breeding advantages of Red-billed Choughs Pyrrhocorax pyrrhocorax inLesser Kestrel Falco naumanni colonies, whileDuncan & Bednekoff (2008) found that cup-nesting species were more abundant near tonests of Cooper’s Hawks Accipiter cooperiibecause of the defence behaviours of thehawks.

Acknowledgments

I would like to thank Richard Dale, Hannah Dugdale,Roy Frost and Jack Street for their help with fieldworkand Forest Enterprise and the Severn Trent WaterAuthority for granting access to their land.

References

Blanco, G., & Tella, J. L. 1992. Protective association ofChoughs nesting in Lesser Kestrel colonies. AnimalBehaviour 54: 335–342.

Duncan,W. J., & Bednekoff, P.A. 2008. Nesting with theenemy. Ethology, Ecology and Evolution 20: 51–59.


Notes

I read with interest the note by Prytherch etal. (Brit. Birds 102: 638) on the relationshipbetween nesting Common Ravens Corvuscorax and Grey Herons Ardea cinerea at ChewValley Lake, Avon. I have been counting up toten heronries in Ceredigion each year forover 40 years, in a county which has had a‘saturation-level’ population of Ravens

(mostly tree-nesters) throughout that time.The mean spacing of Raven nests in farmlanddistricts, where the heronries are, is about 2km apart. It appears from casual observationthat Ravens are considerably more likely tonest close to heronries, say within 500 m,than would happen purely by chance. In fact,most heronries have nesting Ravens much

Dean Nicholson, 8 Park Road, Willingham by Stow, Gainsborough, Lincolnshire DN21 5LF

Common Ravens and Grey Herons

In July 2009, my wife and I watched aCommon Kestrel Falco tinnunculus twiceattempt to take young from the nest of aHobby F. subbuteo in Willingham by Stow,Lincolnshire. The nest was an old CarrionCrows’ Corvus corone nest, c. 10 m from theground in an Ash Fraxinus excelsior tree, inthe middle of open farmland. I had watchedthe nest daily since 14th June and in thattime seen both Hobbies (but usually thefemale) aggressively mob any potential pred-ator that came too close to the nest, includingGrey Heron Ardea cinerea, Common BuzzardButeo buteo, Lesser Black-backed Gull Larusfuscus and Carrion Crow.

At 19.35 hrs on 30th July, a female Kestrellanded in a barley field about 15 m from thenest and was immediately mobbed by thefemale Hobby. Instead of being forced awayfrom the area, however, the Kestrel flewtowards and landed at the top of the nesttree, c. 3 m above the nest. The Hobby divedat the Kestrel repeatedly, calling constantly,but the Kestrel seemed unperturbed. Whenthe Kestrel took off, it hovered very brieflythen suddenly flew fast and direct straight at

the nest. The Hobby chased it and managedto come between the Kestrel and the nest atthe last moment; the Kestrel was closeenough to stretch out a talon toward thethree chicks (by that time aged 16–18 days)before aborting the attempt.

Some five minutes later, the Kestrel reappeared and again landed at the top of thetree just above the nest; the adult Hobby sattight on the edge of the nest, peering up atthe Kestrel. The Kestrel eased its way downthrough the canopy, edging along branchestowards the nest, whereupon the Hobby flewat it aggressively, connecting this time, andforcing it out of the tree. When the two birdsemerged they locked talons and both birdsdropped down behind a hedge out of sight.The Kestrel presumably flew off low acrossthe field, since the Hobby returned andperched near the nest a few minutes later,when the chicks became visible once more. Apair of Kestrels nested in the adjacent fieldbut I assumed that the aggressive Kestrel wasnot one of this pair, which I have seen inclose proximity to the Hobby nest severaltimes without provoking a response.

Dr Geoff Mawson, Moonpenny Farm, Farwater Lane, Dronfield, Sheffield S18 1RA

Common Kestrel attempting to predate Hobby chicks at the nest


nearer than that, and they have quite fre-quently bred within a heronry or at itsperiphery. I doubt that this is due to ashortage of suitable trees, or that Ravens gainsome advantage of concealment from thepresence of the herons. Ravens are top dogsand have few natural predators here. Theadvantage is more probably the improvedprospect of a good meal, whether eggs, chicks(alive or dead) or surplus food supplied bythe herons.

Ravens are undoubtedly bad news forherons. One of my heronries, in a mixedconifer plantation at Llanfair, near Llandysul,was I suspect abandoned because of theattentions of Ravens, which, like the ChewValley pair, were actually using an old heronnest. This heronry, which had existed sinceabout 1925, and had up to 28 nests asrecently as 1988, gradually dwindled to just

two pairs by 2004. The birds failed at the eggstage for three seasons before deserting thesite in 2006; they have so far not returned.Ravens nested within 100 m since at least1967, and actually moved into the heronry inthe late 1990s. At this and other heronriesthere has been direct evidence of Raven pre-dation in the form of heron eggshells or theremains of young herons below the Ravennests, and at one site (Llanllyr, Talsarn) in2009 the farm manager reported twice seeinga Raven taking a young heron from a nest tofeed its own young, barely 50 m away.

I have, incidentally, had one pair of RedKites Milvus milvus using an old heron nestwithin an active heronry, actually in the samelarge Beech Fagus sylvaticus as three occupiedheron nests. The kites failed at a fairly earlystage.

Notes


In June 2009, a pair of Spotted FlycatchersMuscicapa striata reared four young in atypical nest in a wall recess at West Bagbor-ough, Somerset; the young fledged on 27thJune. On 2nd July I saw an adult Spotted Fly-catcher, probably the female, removing nestmaterial, either flying off with the fragmentsor dropping them nearby. The nest wasreduced to approximately 20% of its originalsize, with the lining removed entirely. On 3rdJuly, new materials were brought in, and therebuilt nest was completed on 4th, with anew but scanty lining. The first egg was laid

on the morning of 5th July and by 8th foureggs were being incubated.

Second clutches are not uncommon in theSpotted Flycatcher, and Campbell & Fer-guson-Lees (1972) stated that the same nestmay be used twice in one season, but Ibelieve that rebuilding a nest to such anextent is unusual.

Reference

Campbell, B., & Ferguson-Lees, J. 1972. A Field Guide toBirds’ Nests. Constable, London.

Peter Davis, Felindre, Aberarth, Aberaeron SA46 0LP

Spotted Flycatcher nest reconstructed for second clutch

The Hawfinch Coccothraustes coccothrausteshas recently been added to the Red list ofBirds of Conservation Concern in the UK(Eaton et al. 2009) and also to the list ofspecies monitored by the Rare Breeding BirdsPanel (RBBP). Holling et al. (2009) high-lighted how ‘scarce this species actually is inthe breeding season’, and the numbers pre-sented must surely represent only a tiny pro-portion of those breeding. The populationdecline that triggered its admission to the

Red list was apparent from RSPB woodlandsurveys between 1984/85 and 2003/04 (Eatonet al. 2009). However, it is one of the moredifficult of British birds to monitor effec-tively, owing to its secretive nature and easilyoverlooked song, and the timing of anysurvey work can have a marked effect on thenumbers detected. Hawfinches may breed inloose ‘colonies’ (in part of a larger wood-land), and I have known two such colonieslocally that persisted for several years before

Dr A. P. Radford, Crossways Cottage, West Bagborough, Taunton, Somerset TA4 3EG

Monitoring Hawfinches – another option


being deserted as breeding sites followingwoodland management (thinning). Suchabrupt abandonment of apparently still suit-able habitat can cause additional problems inmonitoring.

My aim in this note is to incentivise othersto establish feeding sites that might help toclarify the local status of the Hawfinch.During recent years I have caught and ringedover 200 in the Forest of Dean, Gloucester-shire, at three feeding sites (see Lewis 2007and Lewis & Clevely 2009 for more detail).This represents a significant proportion ofthe grand total ringed in the UK: 1,641 to2008. The sites are baited with black sun-flower seeds scattered among the leaf litter.The period when birds visit in late winter isfairly limited; numbers peak in the secondhalf of April, before tailing off abruptly inearly May. At this time, the birds are clearlypaired and females are developing broodpatches; they are presumably attracted tofeeding sites when natural food is short andthe females are building reserves for egg-laying, and the tail-off in numbers doubtlessrepresents a departure for local breedingsites. The feeding sites are c. 8–10 km apart

and the limited evidence of movementbetween sites suggests that most are attractedto the site from a fairly local area (a few kilo-metres), and that few birds move more than5 km.

The numbers caught at different sitesshow just how many are present in the localarea, and data from ringing sites may be auseful extra means of estimating the localbreeding population. Birds generally arrive aspart of a small group, and groups continue tovisit throughout the day. Recaptures ofringed birds suggest that each group com-prises mainly different individuals. Table 1confirms that the numbers caught on a dailybasis far exceed the maximum group sizeseen. In the absence of a mark/recapture esti-mate, accumulated daily counts can providereasonably realistic estimates of the numberof birds in the area, and perhaps a more real-istic one than either casual recording or specific surveys provide.

References

du Feu, C., Hounsome, M., & Spence, I. 1983.A single-session mark/recapture method of populationestimation. Ringing & Migration 4: 211–226.

Eaton, M.A., Brown,A. F., Noble, D. G., Musgrove,A. J.,


Notes

Table 1. Capture and population estimate data for Hawfinches Coccothraustes coccothraustes in theForest of Dean, Gloucestershire, 2007–09.

Site Date MG TC M/R ACA spring 2007 10 34 305*

B spring 2007 6 14 34

C 1st May 2008 14 39 133 112

C spring 2008 14 63 239*

B 2nd May 2008 5 14 56 33

B spring 2008 6 17 58

B 26th April 2009 7 27 350* 63

B spring 2009 10 65 102

* Few recaptures (relative to the number of new birds), and these estimates likely to be less reliable.

NotesMG: maximum group size seen during a ringing session or during the spring (in each case ‘spring’ runs from late

March to the first few days of May)TC: number of individuals caught during a session M/R: mark/recapture estimate for a session and for the spring using the ‘du Feu method’ (see du Feu et al. 1983).

Note that the du Feu method was derived in order to help ringers estimate how many birds are in a localpopulation based on a single ringing session, using the number of new birds and recaptures during thatsession. In this case, it has been used for a single session but also across sessions during a ‘spring’ (as definedabove), when the greater number of recaptures gives a more reliable population estimate.

AC: the sum of all the different groups visiting during a session. This assumes that all individuals are different,which is likely to lead to an overestimate. Nonetheless, there is some correlation between M/R and AC (whereM/R is based on sufficient recaptures) and these are likely to give a much better indication of the total numberof birds in the area than MG.


Hearn, R. D.,Aebischer, N. J., Gibbons, D.W., Evans,A., & Gregory, R. D. 2009. Birds of ConservationConcern 3. Brit. Birds 102: 296–341.

Holling, M., & the Rare Breeding Birds Panel. 2009.Rare breeding birds in the United Kingdom in 2006.

Brit. Birds 102: 158–202.Lewis, J., 2007.Why not try catching Hawfinch for a

change? Ringers’ Bulletin 12: 15.— & Clevely, R. 2009. Catching Hawfinch – easier than

you might think! Ringers’ Bulletin 12: 82.

Notes


In May 2009, in easternPoland, we discovered andexamined two HawfinchCoccothraustes cocco-thraustes nests. One, con-taining two young agedaround 8–10 days, was in aEuropean Larch Larixdecidua, close to a lakeused by anglers. It wassoon apparent that theyoung were tied togetherwith discarded fishing line,a considerable quantity ofwhich had been used forthe nest lining. Presum-ably, the young had beenentangled in the line at anearly age and the line hadtightened as they grew,constricting the thighmuscles. We cut the youngfree with scissors (plate124) and removed all theline from the nest beforereplacing the young, whichhopefully survived. Thesecond nest, in a differentarea, was notable for thequantity of bright bluebaler twine used in theconstruction and lining(plate 125). This empha-sised just how often(potentially dangerous)man-made materials areused as nest liners, and wedid contemplate whetherthe colour had affected thepredation risk.

J. M. S. Lewis, Y Bwthyn Gwyn, Coldbrook, Abergavenny, Gwent NP7 9TD; e-mail [email protected]

Hazards of man-made material to nesting Hawfinches

124 & 125. Young Hawfinches Coccothraustes coccothraustes boundtogether with discarded fishing line (124), and Hawfinch nest withbaler twine (125); Poland, May 2009.

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N. J. Westwood and M. Watson, 43 Houghton Road, St Ives, Huntingdon PE27 6RQ



No fewer than 700,000copies of the firstedition were sold,

almost a third of them in the UK, and the CollinsGuide has been indisputably the European fieldguide to birds for a decade now. Does this revisededition give it the wherewithal to maintain thatposition?

Superficially, the new guide is very similar tothe old one. The dimensions are unchanged butthe number of pages has increased by 12%. Themain accounts contain 41 new species (33 ofwhich are the result of taxonomic splits, and mostof these receive significantly fuller treatment);many subspecies receive new or more extensivecoverage; there are 14 new (double-page) spreads(perhaps most notably Larry McQueen’s unlovedAmerican passerines have gone); and in total some60 plates have been redesigned or repainted. Allthe maps have been revised, and the texts revisitedand improved where appropriate. In the appen-dices, both vagrants and introduced species benefitfrom one extra spread.

The taxonomy now gives us wildfowl andgamebirds at the beginning, although not the all-new passerine order that the BOU embraced at thestart of 2010 (though it is hinted that this is likelyto follow in a future edition).

On the whole, after comparing the old and thenew page by page, and pondering the logisticalchallenges of updating an existing layout ratherthan dismantling and starting from scratch, I feltthat the improvement was significant. Most, if notall, of the splits and subspecies that were beginningto look like glaring omissions from the old one arecovered. Taking the warblers as a case study, wenow have full treatment of Eastern Sylvia cras-sirostris and Western Orphean S. hortensis, Asian S.nana and African Desert S. deserti, Booted Hippo-lais caligata and Sykes’s H. rama, Eastern H. pallidaand Western Olivaceous H. opaca, Eastern Phyllo-scopus orientalis and Western Bonelli’s Warblers

P. bonelli, plus an entire spread devoted to chiff-chaffs of one sort or another and redrawn plates ofRadde’s P. schwarzi and Dusky Warblers P. fuscatus.The fact that there is (for example) no Moltoni’s(Subalpine) Warbler S. cantillans moltonii whileEastern Crowned Warbler P. coronatus is still listedin an appendix and (still) without an illustrationmeans that it is not yet the last word on either sub-species or vagrants – but you have to stop some-where.

The names in the first edition were a littlequirky, and they still are. For example, althoughStercorarius parasiticus is now Arctic (not Para-sitic) Skua, and Calcarius lapponicus has revertedto Lapland Bunting, the divers Gavia are still loonsand the wheatears Oenanthe will give you aheadache. Although the call transcriptions are gen-erally excellent, the Swedish influence on some(the flight call of Redwing Turdus iliacus remains‘stüüüf ’) is not so helpful for non-Scandinavians.

As Killian Mullarney has pointed out elsewhere(Birdwatch 213: 30–32), perhaps the great travestyof this update was that, just four months beforethe publisher’s deadline, the number of new pagesavailable suddenly jumped from 24 to 48; at thatlate stage, much of that precious allocation endedup being used to expand the index, an inexplicablelack of foresight that reflects badly on the pub-lisher. Bearing in mind the guidelines that theauthor and the artists were working with until thislate stage, I think one has to conclude that theimprovements in the new version are impressive.

Is it still the number-one field guide to the birdsof the region? Unquestionably, yes. Is it worthupgrading your old one? Yes, on the whole I thinkit is, and here at least the publisher should be com-plemented in releasing the paperback versionalmost as soon as the hardback (which surely fewpeople will buy). The more user-friendly paperbackis well worth the relatively modest investment.

Roger Riddington

ReviewsCollins Bird Guide 2nd editionBy Lars Svensson, Killian Mullarney and Dan ZetterströmCollins, 2009448pp, over 3,500 colour illustrations, mapsPbk, ISBN 978-0-00-726814-6 Subbuteo code M17550 £17.99 BB Bookshop price £15.99Hbk, ISBN 978-0-00-726726-2 Subbuteo code M16237 £25.00 BB Bookshop price £22.00

The BB Bookshop, brought to you by Subbuteo Natural History Bookswww.wildlifebooks.com/bb, and see our list after Recent reports



Reviews

Helm Dictionary of Scientific Bird NamesBy James A. JoblingChristopher Helm, 2010Hbk, 400ppISBN 978-1-4081-2501-4 Subbuteo code M02538£40.00 BB Bookshop price £35.00


The first version ofthis book was pub-lished by OUP in1991, and this is theturbocharged V8

model: bigger, heavier and more powerful. Theonly thing missing from the first book is theartwork decorating the vacant spaces at the end ofeach ‘chapter’. Since then, a lot of water has flowedunder many taxonomic bridges, with the fragmen-tation of large genera into smaller units and thepromotion of several hundred subspecies tospecies, providing much new material for theauthor. There are now over 20,000 entries com-pared with 8,500 in the 1991 version.

Following a page of acknowledgments, a glos-sary and a list of abbreviations, a ten-page ‘Intro-duction’ includes the rationale for the new book, abrief history of the binomial system and a shortsummary of the main rules of the ICZN, and ananalysis of the main types of bird names. Thenfollows seven pages of ‘How to use the dictionary’,which explains the conventions used. The authoradmits to a limited treatment of eponyms, givingjust the basic who, when and occupation, andreaders are directed elsewhere for more completebiographies.

The meat of the book consists of 483 double-column pages (a 48% increase) of dictionary-likeentries with generic names (initial capital) andspecific names in alphabetical order explaining thederivation and meaning, with around 25–60entries per page. The new publisher has mademore efficient use of space with a smaller, but stillreadable, font and closer line spacing. Manyentries have been expanded by the addition of whoused it, the bird or group to which it applies and

the addition of synonyms. The entry for somemore frequently used words has been expandedfrom a few lines to almost a column. Theexpanded bibliography now runs to 18 pages.There cannot be that many with sources as diverseas the works of Aristotle, Pliny and a Malay-English dictionary!

In the Introduction to the earlier book, but notthe present one, the author mentioned that theabolition of diacritical marks by the ICZNdeprived people of a possible clue to pronuncia-tion; the same wording now appears under theentry for aedon, but has a much wider application.The adjacent initial vowels in this word, and someothers with a similar spelling, should be pro-nounced separately: ay-eedon. As few people arenow encountering classics in their education, amore general guide to pronunciation would havebeen helpful. I have heard cisticola pronounced assis-TIK-ole and sisti-Kœ-le. As the book tells us,the word is derived from Greek kistos, a shrub, andLatin colere, to dwell, so perhaps the initial ‘c’should be hard.

As an aid to use, each page is thumbnailed withthe appropriate letter. It would take a classicalscholar of considerable expertise to take issue withthe author, far beyond my distant struggles withCaesar’s Gallic Wars and Xenophon’s Anabasis. Ifyou ever wondered what those strange wordsmeant and where they came from, this book tellsyou. You learn quite a lot about Greek and Latinmyths too.

ReferenceJobling, J. A. 1991. A Dictionary of Scientific Bird Names.

OUP, Oxford.

F. M. Gauntlett

The Status of Birds in NottinghamshireBy Jason ReeceHoopoe Press, 2009. Pbk, 156pp, line-drawingsISBN 978-0-9560592-0-8 Subbuteo code M20573£9.50 BB Bookshop price £9.00

Despite its landlocked position, Nottinghamshirehas been responsible for some major birds inrecent years, including Britain’s first Redhead

Aythya americana, at Bleasby in March 1996, andthe Nottingham Cedar Waxwing Bombycillacedrorum, which arrived the previous month. The


Reviews

county has an impressive list of 325 species and nofewer than four firsts for Britain, so The Status ofBirds in Nottinghamshire has the potential forsome interesting reading.

The first assessment of the county’s birds wasNotes on the Birds of Nottinghamshire, by JosephWhitaker in 1907, and the most recent was TheBirds of Nottinghamshire: past and present, byAustin Dobbs in 1975. Though all historicalrecords are noted, the scope of the present book isfocused on the period 1975–2007, coinciding withthe political boundary changes of 1974 and the lastreview of the county’s birds in 1975.

A brief description of the county is organisedby topography, geology and land use. The mainbody of the book embraces details of all species

recorded in Nottinghamshire, with first and lastdates for migrants, significant site counts, recordsof all rare vagrants and a list of key sites with gridreferences. The species accounts are pleasantlyinterspersed with the excellent line-drawings oflocal artist Chris Orgill. The book is thread boundand approximately 50% cheaper than it wouldhave been in hardback, which should enhanceboth its durability and appeal.

As an instant guide to the breeding and raritystatus of all the county’s birds, and with all profitsfrom sales being donated to NottinghamshireBirdwatchers, I can recommend this book toanyone interested in the region’s birds.

Ian Cowgill



Darren Woodhead’s Up River is based on threeyears as artist in residence around Carlops and thevalley of the North Esk River. The subject mattervaries from bleak snowscapes, where you can feelthe cold blasting from the page, to intimate studiesof nesting Common Buzzards Buteo buteo andpages of fungi, which have a cosy Victorian feel tothem. My favourites include the series of water-colours of Bullfinches Pyrrhula pyrrhula and amassive composition of Northern LapwingsVanellus vanellus and Dunlins Calidris alpina. Iwas lucky enough to see this in the flesh at theBirdfair; it is stunning. Which leads me to my onlytiny criticism, the originals are so big that some-times, even in a good-sized book such as this, thereduction of the image is such that the detail canbecome a little noisy – maybe too much of a goodthing squeezed into a small space.

By way of a contrast, James McCallum haschosen one species as his subject. For many years

D a r r e nWo o d h e a dand JamesMc C a l l u mare foremostamong the

most skilled exponents of sketching wildlife in thefield. Their work is inspired by first-hand observa-tions and executed in the field with uncanny accu-racy and painterly freedom crafted by many yearsof sitting tucked away in the nooks and crannies ofour country’s wildest habitats. All-weather condi-tions are endured in this pursuit – I can only praythat they have invested wisely in haemorrhoid-cream futures!

Up River and Wild Skeins and Winter Skies arethe latest publications to showcase these talents,revealing the respective artists’ latest ventures intothe wilds of Britain, and it is a particular delight toreview these books side by side.

Up River: the song of the EskBy Darren WoodheadBirlinn, 2009Hbk, 160pp, colour illustrations throughoutISBN 978-1-84158-8346 Subbuteo code M20570£29.99 BB Bookshop price £27.00

Wild Skeins and Winter Skies: paintingsand observations of Pink-footed GeeseBy James McCallumSilver Brant, 2009Hbk, 100pp, colour illustrations throughoutISBN 978-0-9541695-4-1 Subbuteo code M20556£35.00 BB Bookshop price £31.50



Reviews

he has painted, drawn or simply watched with carethe Pink-footed Geese Anser brachyrhynchus of hisnative Norfolk. Wild Skeins and Winter Skies is theculmination of this work. It is a brave man whoproduces a book of paintings based purely on onespecies, but I think he is canny and knows his localmarket extremely well and, of course, it is carriedwith the usual McCallum flair. The pages radiatewith light and life, the geese gaggle in their effortsto get off the pages! The hours put into this andthe dedication to his beloved geese is clear to see,but this is not just a book of pretty sunsets, there isplenty to be gained for both the art lover and the

serious ornithologist. James has always pridedhimself on his roughy-toughy out-in-all-weathersapproach to his art, but I couldn’t help but noticethe word ‘van’ cropping up a few times – is hegoing soft with age?

Both books are large format, well produced andlovely to hold – I have a thing about holding books!Both have been written in a way that is almost asevocative as the paintings themselves and are sym-pathetically designed. Reason to buy – simply toadmire these artists at the top of their game.

Dan Powell

Wildlife Photography Masterclass:a beginner’s guide to wildlife photographyBy Chris Gomersall and David TiplingLPS Creative Media, 200963 min DVDSubbuteo code M60045£19.95 (DVD) BB Bookshop price £17.95


photography hotspot.The main session on processing images in the

‘digital darkroom’ (workflow) provides a goodgrounding for the beginner in what can easilybecome a highly complex and confusing area,given the wide range of different software pro-grams on offer. Clever camera work clearly showsthe actions performed on the computer, zoomingin and out of the screen menus to reveal moredetail.

The additional ‘special features’ at the end ofthe DVD provide some extra pointers, includingthe intriguingly named ‘Exposure Bootcamp’ – atitle which has more macho promise than it actu-ally delivers. In some ways these extras, particu-larly the additional session on image optimisationusing Adobe Lightroom, come across as slightlyvague and random, and may hinder rather thanhelp the main presentation. However, they doillustrate the point that every photographer doesthings slightly differently, and that beginners needto experiment to discover what works best forthem.

This DVD covers a lot of ground and, thanks tothe wealth of skill and experience on offer fromthe two photographers, provides a clear and well-presented introduction to wildlife photography,with lots of practical tips and advice.

Bill Baston

This DVD features two of the UK’s best-knownwildlife photographers, Chris Gomersall andDavid Tipling. Both come across well, and theDVD format is useful in allowing us to watch themat work in the field (and in the back garden), andalso in the ‘digital darkroom’.

The presentation begins by looking at the ‘kitbag’, and sets out clearly the pros and cons ofcompact cameras, digiscoping (only briefly men-tioned) and digital SLRs with their various lensoptions. A useful review of hides and camouflagegear is also included, along with frequentreminders that the welfare of the subject mustalways be the main consideration. Equally sensibly,as this presentation is aimed at the beginner, thediscussion focuses mainly on the small-to-medium-range lenses rather than the more expen-sive, heavyweight telephotos, and discusses whatcan and cannot be achieved with the variousoptions in this range.

This emphasis continues with a series of prac-tical sessions, involving some approachable andaccessible subjects, including a family of local RedFoxes Vulpes vulpes. Advice on using food anddrink to attract wildlife closer to the cameraincludes the use of hazelnuts to attract squirrels,which some photographers might find counter-productive! Farther afield, a trip to Bempton Cliffsprovides some useful guidance on focusing techniques and problems of exposure at this bird-


Peregrine Falcon Populations:status and perspectives in the 21st centuryEdited by Janusz Sielicki and Tadeusz MizeraTurul & Poznan University of Life Sciences, 2009Hbk, 800pp, numerous colour photos and figuresISBN 978-83-920969-6-2 Subbuteo code M20455£75.00 BB Bookshop price £69.95

Reviews

These two CDs present 311 recordings of the callsand other sounds of 103 species of birds of prey –including all those regularly occurring in theWestern Palearctic. In addition, the selectionoffered goes beyond that region to incorporate arange of species from each of the continents,although it is not clear what criteria were used tomake the choice. There are over 320 raptors in theworld, so only a third are represented here – andwhile the selection offered for Africa covers mostof the commoner species, the same cannot be saidfor the other continents. There are some strangeomissions. For example, several of the caracarasare included, but not Red-throated Caracara Dap-trius americanus, which is one of the most vocalraptors I know. From Australia the Black Falcon

Falco subniger is featured – but nothing else. At theother extreme, a recording of chicks of theneglectus race of Common Kestrel F. tinnunculusfrom the Cape Verde Islands is included.

Of particular interest are a series of ten record-ings of Red-footed Falcons F. vespertinus, repre-senting the entire breeding cycle from theestablishment of a territory to calls of nestlings atthe nest and on fledging, as well as alarm calls. Therecordings are clear and the booklet provides briefdetails of each recording, although often withoutany indication of when or where the recording wasmade. Further details, including a full list of thespecies included, are available at www.birdsongs.de

Keith Betton


The Sounds of Raptors and FalconsBy Karl-Heinz Dingler, Christian Fackelmann and Andreas SchulzeMusikverlag Edition AMPLE, 2009Two CDs (156 mins) and 36-page booklet in English, French and GermanISBN 978-3-938147-17-7. Subbuteo code V10081£17.95 BB Bookshop price £15.95


This attractively produced volume consists of nofewer than 62 short papers, most of which werepresented at the Second International PeregrineConference, held near Poznan, Poland, in Sep-tember 2007. As befits the conference’s title, thepapers are drawn from across the globe, thoughmost (roughly 45%) concern central and easternEurope. Such a bias is not unwelcome, given thatthis geographical area has not, to my knowledge,been well covered in earlier English languagereviews on the Peregrine Falcon Falco peregrinus.

The papers are varied and split into six broadcategories: population dynamics, food and feeding,interactions with humans, reintroductions, urbanpopulations, and, as a bonus not even hinted at inthe book’s title, a concluding section consisting offour interesting papers on the Saker Falcon F.cherrug in central Europe. There are plenty ofintriguing facts to be found, and issues to be thoughtabout. For example, despite a ban on the use ofcertain organochlorine biocides in Germany, levels

of chemical contamination of Peregrine eggs in thatcountry have not fallen as far as expected, probablyowing to DDT residues from anti-malaria cam-paigns in the tropics being redistributed through theatmosphere to colder regions of the globe. Also dis-turbing is the matter of male hybrid falcons thathave escaped from captivity mating with wild femalePeregrines (female hybrids are apparently infertile),as has occurred recently in eastern Germany and inEngland. In this connection, it was also interesting toread that natural hybridisation has taken placebetween certain species of large falcon where theirranges meet in North America and Eurasia. Severalcontributions discuss the decline and subsequentrecovery of various Peregrine populations, while ona lighter note there is even a paper considering theuse of the images of falcons on stamps.

Enthusiastic students of large falcons are sure tofind this book informative and thought-provoking.

Pete Combridge



Far-flung seabird islands in the South Pacific andthe South Atlantic are set to receive an anti-rodentonslaught that could finally safeguard their endan-gered seabird communities.

Both Henderson Island and South Georgia areUK Overseas Territories that are spectacularlyremote with internationally important seabirdpopulations. Henderson Island is in the Pitcairngroup in the eastern South Pacific, 5,000 km fromNew Zealand; South Georgia is in the SouthAtlantic, 1,500 km east of the Falklands.

South Georgia is home to 30 million breedingseabirds. The key species are Grey-headed Alba-tross Thalassarche chrysostoma, Northern GiantPetrel Macronectes halli, White-chinned Petrel Pro-cellaria aequinoctialis, Antarctic Prion Pachyptiladesolata, Macaroni Penguins Eudyptes chrysolophus(half the world population) and the endemicSouth Georgia Shag Phalacrocorax georgianus. ButSouth Georgia is also home to several millionBrown Rats Rattus norvegicus, the descendants ofthose inadvertently introduced by nineteenth-century whalers and sealers. The rats devour theeggs and chicks of all ground-nesting birds andwill be targeted in a comprehensive eradicationprogramme scheduled for February 2011, master-minded from… Dundee.

Invasive rodents have been removed success-fully from more than 300 islands worldwide butthe South Georgia operation involves two helicop-ters spreading poisoned bait over every squaremetre of ice-free land on the 170 km-long island,using the precision of GPS navigation. ‘It’s easilythe largest rat-eradication effort in the world, atleast seven times bigger than anything anyone hastackled before,’ said Tony Martin, Professor ofAnimal Conservation at the University of Dundee,who is in charge of the multi-million-poundproject. ‘My job is to nail every last rat and to makesure we don’t poison too many non-target species.It’s no good if we end up missing the last couple ofrats, because they reproduce so quickly and withina few years their numbers will be back up topresent levels.’

The only barriers to the rats on South Georgiaare the ice tongues of the glaciers which protrudeout to sea and isolate some bird colonies. But theseglaciers are retreating rapidly, which means thatrats are able to find new bird colonies to attack,Prof. Martin said: ‘The glaciers are retreating at ahell of a pace, sometimes visibly changing year on

year. When the snout of a glacier melts away froma beach, the rats just walk around it. It’s happeningvery quickly, which is why we need to work fast.’

Pellets of a cereal bait loaded with an anti-coagulant poison will be spread across all rat-infested parts of the island by helicopter. Thepoison, which quickly degrades and does not dis-solve in water, works by getting into the liver andcausing internal bleeding. It does not kill immedi-ately and makes the rats sensitive to light so it ishoped they will retreat to their burrows to dieunderground rather than dying out in the openwhere their poisoned corpses could be eaten byseabirds.

Meanwhile, the RSPB is researching the eradi-cation of the Pacific Rat R. exulans on HendersonIsland in August–September 2011 or 2012. Hen-derson is the most pristine raised coral atoll ofsignificant size in the world. Declared a UNESCOWorld Heritage Site in 1989, the island has fourendemic landbirds: the Henderson Fruit DovePtilinopus insularis, Henderson Lorikeet Vinistepheni, Henderson Crake Porzana atra and Hen-derson Island Reed Warbler Acrocephalus taiti. It isalso the only known nesting site of the HendersonPetrel Pterodroma atrata and represents the ‘globalheadquarters’ of the highly threatened gadflypetrel group, with four breeding species.

Evidence from fieldwork has shown that PacificRats kill 99% of the chicks of the four species ofpetrel (Henderson Petrel, Herald Petrel P.heraldica, Murphy’s Petrel P. ultima and KermadecPetrel P. neglecta) that occur on Henderson. Popu-lation modelling shows that these petrels are inlong-term decline, with their numbers havingdropped from the order of millions before ratsarrived to just thousands now. The rats are alsolikely to be reducing populations of turtles andother wildlife on Henderson, and competing forfood with the fruit dove, lorikeet and crake.

One of the RSPB’s key aims is to convince theUK Government to accept and honour its legalobligation to protect the biodiversity of thisunique island, and another is to secure funding forthe removal of rats from Henderson Island. If rateradication (estimated cost: £1.5 m) is successful,it’s believed that seabird populations could beboosted one hundredfold within a relatively shorttime frame. And a paper about Henderson Islandin the series describing key Important Bird Areas(IBAs) will appear in BB later this year.

News and commentCompiled by Adrian PitchesOpinions expressed in this feature are not necessarily those of British Birds

Global war(farin) declared on rats as UK seeks to save our seabirds



News and commentNews and comment

Waxwings on the move

Raven increase does not spell the end for threatened waders

Common Ravens Corvus corax are not responsiblefor the dramatic declines in the numbers ofwading birds seen in many parts of the UKuplands, according to the results of a new study byRSPB and the University of Aberdeen’s Centre forEnvironmental Sustainability (ACES).

The uplands are home to many waders,including European Golden Plovers Pluvialis apri-caria, Northern Lapwings Vanellus vanellus,Dunlins Calidris alpina and Eurasian CurlewsNumenius arquatus, which have declined by up to50% in the last quarter century. In contrast, Ravenpopulations have recovered in many parts of theUK during that same period. These patterns,together with the knowledge that Ravens will eatthe eggs and chicks of upland waders, have ledsome to suggest that Ravens are the cause of waderdeclines, and to demands by some land managersfor licences to kill Ravens to protect uplandbreeding birds.

RSPB data from sites distributed across morethan 1,700 km2 of the UK’s uplands were used toexplore the patterns of change in Raven numbersand wader abundance over the past 20 years. In theUK, the Breeding Bird Survey shows that from1994 to 2007 the Raven population increased by134%.

The research found little evidence to suggestthat wader populations were more likely to declinewhere Raven populations had increased, however.This implies that other factors, including changesto habitat and vegetation cover, and a generalincrease in other predators such as Red FoxesVulpes vulpes, could be responsible for these large-scale changes. The study did find weak associationsbetween increases in Ravens and declines in Lap-wings and Curlews, but these were not statisticallysignificant. Further research is needed to explorethese patterns and consider the impact of habitatchanges on waders.

Aberdeen is the UK’s capital city of WaxwingsBombycilla garrulus. Its location in relation toScandinavia means that if there is any widespreadmovement of Waxwings, some usually turn up inAberdeen. The abundance and variety of berries inthe city attracts and holds birds and in the largerinvasions flocks of over 1,000 have been recorded.

Grampian Ringing Group has been colour-ringing Waxwings in and around Aberdeen since1988. Thanks to many birders, photographers andmembers of the public providing sightings and

recoveries of dead birds, the results have producedan interesting picture of the birds’ southwardmovements through Britain & Ireland after land-fall in North-east Scotland.

Unfortunately, once the Waxwings depart totheir remote summer breeding grounds, few areever heard of again. So, when small numbersstarted to arrive in February 2010, it was anexciting surprise to have a colour-ringed birdreturn to the same village where it had been ringed(as an immature female) in February 2009.

Plate 126 shows the colour-ringed Waxwing feeding onapples in the garden of Walterand Ann Burns in Kintore, nearAberdeen. This is only the thirdconfirmed record of a Waxwingreturning to the UK in a subse-quent winter from over 4,500birds ringed. In contrast, anadult male ringed in Aberdeenon 31st March 2005, during thevery large invasion of winter2004/05, was killed by a cat thefollowing February… in aRussian village east of the Urals,3,714 km northeast of itsringing location the previouswinter.

(Contributed by RaymondDuncan)

126. Adult female Waxwing Bombycilla garrulus, Kintore, North-eastScotland, February 2010, returning to the very same village where ithad been ringed a year earlier.

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News and comment

The Big Mammal YearMany (most?) birders keep a year list, be it fortheir country, county or just for their garden.Those 2010 British year lists should soon be accu-mulating their first Barn Swallows Hirundo rustica,Common Whitethroats Sylvia communis andWillow Warblers Phylloscopus trochilus.

Some well-heeled and/or well-travelled peoplealso keep a world year list. The record breakers inworld birding are Alan Davies and Ruth Miller,whose Biggest Twitch around the world in 2008yielded a staggering 4,341 species, a quantum leapbeyond the previous record of 3,662 seen in asingle year (www.thebiggesttwitch.com)

Now two South Africans, Rich Lindie andHayley Wood, have decided to make 2010 a ‘bigyear’ – for mammal watching. And they’re hopingto raise $100,000 for mammal conservation alongthe way. There are 5,500+ species of mammal inthe world (roughly half the c. 10,000 bird species)and the couple hope to see about 400. Theirs is notan attempted record-breaking tour but an oppor-tunity to see, photograph and raise the profile ofthe most endangered species. Roughly one-fifth ofmammal species fall into this category. To find outmore, visit www.thebigmammalyear.com

Bumblebees not so vulnerableRenowned weather watcher Norman Elkinsresponded to the recent piece about the Big Freezeand the threat to hibernating bumblebees (Brit.Birds 103: 133).

He says: ‘Regarding bee mortality, I fear thecomments by the Bumblebee Conservation Trustare rather misleading. Not only have we had airtemperatures as low as this winter’s in previouswinters (the -20°C being the exception rather thanthe rule), but such low minimum temperaturesusually occur only above extensive snow cover(which radiates very efficiently, leading to severetemperature decreases overnight). However, thesnow acts as a blanket, keeping ground tempera-tures at or just above zero. Thus bees hibernatingunderground are well protected from the very lowtemperatures (with -11°C and 20 cm of snow inmy garden, I was still able to dig vegetables fromthe soft unfrozen ground beneath).

‘With such widespread snow across the UK, Isuspect that most bees were quite comfortablebeneath the snow cover. If this was not the case,there wouldn’t be very many bees left in northernEurope!’

Seabird conservationist nets$150,000 award to researchfisheriesDr Ben Sullivan, a Tasmanian-based co-ordinatorfor BirdLife’s Global Seabird Programme, has beenawarded a 2010 Pew Fellowship in Marine Conser-vation for his project to reduce seabird ‘bycatch’(the catching and killing of non-target species) inopen ocean longline and trawl fisheries.

The Pew Fellowship in Marine Conservationgives recipients $150,000 for a three-year scientificresearch or conservation project designed toaddress critical challenges facing our oceans. DrSullivan’s fellowship will utilise the existing Alba-tross Task Force to conduct research and developbest practices for reducing the killing of seabirds inmany of the bycatch ‘hotspots’ around the world.

‘I am thankful to the Pew Marine FellowsProgram for allowing me to research new andbetter ways to protect seabirds from unnecessarydeaths at the hands of fishing gear,’ said Dr Sul-livan. ‘Finding new solutions to the problem ofbycatch in fisheries will signify an important steptoward stopping the decline of many seabird populations.’

Biking birder updateGary Prescott (see Brit. Birds 103: 135) has had aneventful start to his birding/biking year aroundBritain, in the coldest British winter for 30 years.

Broken lights after a fall on the ice, three daysstuck in Hemel Hempstead because of the snow(he finally escaped along the towpath of the canalto Uxbridge, pushing the loaded bike the wholeway), and nearly being arrested in London’s StJames’s Park for looking and acting like a terrorist(heavy camouflaged fatigues to combat the snow,plus binoculars and notebook) were just some ofthe challenges he faced.

By early March, he had reached Cornwall and149 species for his year list, including goodies suchas Green-winged Teal Anas carolinensis, LesserScaup Aythya affinis, Ring-necked Duck A. collaris,Great White Egret Ardea alba and Great GreyShrike Lanius excubitor.

Follow Gary’s journey on www.bikingbirder.co.uk, where his itinerary is listed – if you can offercompany or a bed for the night at any point, pleaseget in touch. His mission is to cycle to every RSPBand WWT reserve in the UK, in support of thosetwo charities plus Asthma UK.



It seemed too good to be true. A much-hoped-for– and frequently claimed – first for Britain hadbeen staked out in Cumbria. Indeed, it seemed tobe ‘nailed on’ for anyone wishing to make thejourney to the Lake District. The Black Wood-pecker Dryocopus martius at Ling Fell near Bassen-thwaite Lake was indeed nailed on, however, assoon became apparent.

The first report was phoned through to theBirdGuides sightings hotline www.birdguides.comby a local resident, and she was very detailed in herdescription: ‘I was on the lower slopes of Ling Fell,near Wythop Mill, and the Black Woodpecker wason a telegraph pole. Because I was coming down-hill towards him, he was not far above eye-level atfirst. He stopped pecking and froze, and though Istopped and watched for a good five minutes, hedid not move. I’ve checked the books and there’sabsolutely no doubt that’s what he was.’

She was perfectly correct in her identificationand the bird is still showing well – it’s a metalmodel nailed to an electricity pole. It transpiredthat power company United Utilities use models ofBlack Woodpeckers to deter Great Spotted Wood-peckers Dendrocopos major from drilling holes intheir wooden electricity poles, which cost up to£1,500 each.

Polly Rourke from United Utilities told BBCLook North: ‘We’ve been using these models forabout five years because (Great Spotted) wood-pecker attack is one of the biggest causes of elec-tricity pole damage… They make huge holes in thepoles, which can render them unstable. It makes itimpossible for our engineers to climb them andthere could be a risk of power cuts.’ And no,despite the date on the front cover of BB, this isnot an April Fool!

News and comment

A reminder that the 34th BB Bird Photograph ofthe Year competition is still open for entries. Thecompetition is FREE to enter and up to threeimages of Western Palearctic birds taken during2009 may be submitted. The first prize is a cash

prize of £1,000, and the closing date for entries is24th April.

For full details of the rules and how to submitentries, visit www.britishbirds.co.uk/bpy.htm

BB Bird Photograph of the Year, sponsored by Warehouse Express

And finally: Black Woodpecker in Cumbria – still showing well

The World’s Rarest Birds A rather different photographic competition isnow online at www.theworldsrarestbirds.com

Photos of 623 species, listed on the website, areeligible for the competition and many will be usedin The World’s Rarest Birds, which will be pub-lished in the first half of 2011.

The World’s Rarest Birds has evolved from RareBirds Yearbook and will be produced byWILDGuides, a not-for-profit publisher and, aswith Rare Birds Yearbook, proceeds from sales willbe donated to BirdLife International’s PreventingExtinctions Programme. The new format will beexpanded to cover the 362 species categorised asEndangered as well as the world’s 192 CriticallyEndangered species.

For more information contact Erik [email protected] or Andy [email protected]

Owls of the world – a requestfor photographsIn 2012, A&C Black will publish a definitive photographic guide to the world’s 250 species ofowls, and the process of sourcing and selectingphotographs is now well underway.

Owls of the World is being written by Finnishowl guru Heimo Mikkola, and the publisherswould like to invite the submission of images(preferably digital) for use in the book, which willplace particular emphasis on plumage variationand racial separation. Photographs of young birds,island endemics and adults in flight are particu-larly welcome.

If you think that you might be able to help,please contact Ellen Parnavelas: [email protected]



Red-breasted Goose Branta ruficollis Long-stayer in Devon to 28th February; Pitsea(Essex), 4th–5th March.

American Wigeon Anas americana Long-stayers in Co. Cork and Dumfries & Gal-loway. Baikal Teal Anas formosa TacumshinLake (Co. Wexford), long-stayer seen again,19th–23rd February. Black Duck Anasrubripes Long-stayer in Co. Mayo; also Colli-ford Lake (Cornwall), 16th February to 6thMarch. Blue-winged Teal Anas discors Long-stayer in Co. Dublin.

Ferruginous Duck Aythya nyroca Chew ValleyLake (Avon), again, 20th February. LesserScaup Aythya affinis Long-stayers in Cornwalland East Glamorgan; also Lewis (OuterHebrides), two, 10th February; EglwysNunydd Reservoir (East Glamorgan), inter-

mittently, 13th February to 5th March; Hog-ganfield Loch (Clyde), 22nd February to 6thMarch; Chew Valley Lake, 7th March.Common Eider Somateria mollissima Drake ofAmerican race dresseri, Glasagh Bay (Co.Donegal), from early January to 3rd March.King Eider Somateria spectabilis Burghead(Moray & Nairn), long-stayer joined byanother from 19th February to 1st March.Bufflehead Bucephala albeola Abbotsbury/Langton Herring/The Fleet (Dorset), 6th–8thMarch. Hooded Merganser Lophodytes cucul-latus Long-stayer in Cleveland to 1st March.

Pacific Diver Gavia pacifica Between DoorusPier (Co. Galway) and Finvarra (Co. Clare),again, 4th–6th March.

Cattle Egret Bubulcus ibis Sennen, up to twolong-stayers to 3rd March, Tresillian/Tre-semple Pool, up to three long-stayers to 19thFebruary, Wadebridge, 19th February, andHayle Estuary (all Cornwall), 6th March;Great Island (Co. Cork), 4th–28th February;Walmer (Kent), 2nd March; Sharpham Park(Somerset), long-stayer again 3rd–7th March.Great White Egret Ardea alba Records fromCambridgeshire, Carmarthenshire, Cheshire& Wirral, Dorset, East Glamorgan, GreaterLondon, Gwent, Hampshire, Kent, Lan-cashire & N Merseyside, Northamptonshire,Somerset, Suffolk, Warwickshire, Yorkshire.

Recent reportsCompiled by Barry Nightingale and Eric Dempsey

This summary of unchecked reports coversearly February to early March 2010.

Headlines American waterbirds providedmost of the highlights, including two Pied-billed Grebes, a Pacific Diver and a CommonEider of the American race dresser i inIreland, and a Bufflehead in Dorset.A trio ofPhyl loscopus warblers injected somepasserine interest, particularly a DuskyWarbler, the first for the London area.

127. Drake Common Eider Somateria mollissima of American race dresseri (right-hand bird above, inboth cases), Glasagh Bay, Co. Donegal, February 2010; potentially the first record for the WesternPalearctic.

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Recent reports

Laughing Gull Larus atricilla Between Bexhilland Cooden (Sussex), 14th–20th February.‘Thayer’s Gull’ Larus glaucoides thayer iCleggan (Co. Galway), from 19th January to10th February. Bonaparte’s Gull Chroico-cephalus philadelphia Baltimore (Co. Cork),long-stayer to 5th February; Lligwy Bay(Anglesey), 1st–2nd March; River Taff (EastGlamorgan), 7th–8th March. Forster’s TernSterna forsteri Long-stayer in Co. Galway to6th March.

Snowy Owl Bubo scandiacus Lewis, 17th February.

Penduline Tit Remiz pendulinus Grove Ferry(Kent), long-stayer to 19th February;Rainham Marshes (Greater London/Essex),15th February.

Pallas’s Leaf Warbler Phylloscopus proregulusBraintree (Essex), 1st March. Hume’sWarbler Phylloscopus humei Strumpshaw Fen(Norfolk), 13th February. Dusky WarblerPhylloscopus fuscatus Walthamstow (GreaterLondon), 14th–21st February.

Rose-coloured Starling Pastor roseus Kendal(Cumbria), long-stayer to 1st March.

B l a c k - t h r o a t e dThrush Turdusatrogularis Newholm(Yorkshire), long-stayer to 28th Feb-ruary.

European SerinSer inus ser inusRainham Marshes,two long-stayers to24th February. LittleBunting Ember izapusi l la Dunnet(Highland), long-stayer to 7th March;Sconner (Corn-wall), 18th Februaryto 7th March;Lundy (Devon),22nd–24th Feb-ruary.

Glossy Ibis Plegadis falcinellus Long-stayersfrom the 2009 influx comprised three inSomerset and one in Co. Wexford.

Pied-billed Grebe Podilymbus podiceps LoughGur (Co. Limerick), 19th February to 6thMarch; Lough Ateduan (Co Clare), 5th–7thMarch.

Black Kite Milvus migrans Gigrin Farm,Rhayader (Radnorshire), long-stayer to 7thMarch. Gyr Falcon Falco rusticolus Islay(Argyll), found dead 14th February; Tresco(Scilly), 13th February and 5th March; MaerLake, 18th February, presumed same nearNewquay (both Cornwall), 24th February.

American Golden Plover Pluvialis dominicaWaxham (Norfolk), 16th February; Cranwell,1st March, presumed same Brant Boughton(both Lincolnshire), 2nd March. Long-billedDowitcher Limnodromus scolopaceus MaerLake, 12th–19th February; Burton Marsh/Inner Marsh Farm (Cheshire & Wirral),14th–16th February; Tacumshin Lake,20th–23rd February; Ashton’s Callows (Co.Tipperary), 5th March; Banks Marsh (Lan-cashire & N Merseyside), 7th–8th March.

Recent reports

128. Long-billed Dowitcher Limnodromus scolopaceus,Tacumshin Lake,Co.Wexford, February 2010.

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Documents

British Birds - Sample Copy