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MOULTING BIRDS IN LOFOTEN AND VESTERÅLEN, AUGUST 2009 Report commissioned by the Norwegian Institute for Nature Research (NINA)

NATIONAL ENVIRONMENTAL RESEARCH INSTITUTEAARHUS UNIVERSITY

Report request 2010

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NATIONAL ENVIRONMENTAL RESEARCH INSTITUTEAARHUS UNIVERSITYAU

Report request 2010

MOULTING BIRDS IN LOFOTEN AND VESTERÅLEN, AUGUST 2009Report commissioned by the Norwegian Institute for Nature Research (NINA)

Rasmus Due NielsenIb Krag Petersen

Data sheet

Title: Moulting birds in Lofoten and Vesterålen, August 2009

Report request: Report commissioned by the Norwegian Institute for Nature Research (NINA)

Authors: Rasmus Due Nielsen & Ib Krag Petersen Department: Department of Wildlife Ecology and Biodiversity Publisher: National Environmental Research Institute ©

Aarhus University - Denmark URL: http://www.neri.dk

Year of publication: April 2010 Editing completed: April 2010 Referee: Aksel Bo Madsen

Financial support: Norwegian Institute for Nature Research

Please cite as: Nielsen, R.D. & Petersen, I.K. 2010. Moulting birds in Lofoten and Vesterålen, August 2009. Report commissioned by the Norwegian Institute for Nature Research (NINA) National Environmental Research Institute, Aarhus University, Denmark. 24 pp. http://www.dmu.dk/Pub/NINAreportLofoten.pdf

Reproduction permitted provided the source is explicitly acknowledged

Abstract: The results of an aerial survey on Lofoten and Vesterålen in August of 2009 are presented in this report. No prior aerial survey of moulting birds during late summer has been carried out in the area. Counts of breeding/overwintering birds have shown Lofoten to be very important for a number of bird species.

Most of the breeding birds had left the area in August of 2009. Puffins were only numerous south of Værøy though not nearly as abundant as during the breeding season. Gulls together with Cormorants sp. were the most commonly observed bird species distributed along all coast-lines. They were found mainly on small rocky islands and shores.

No attempt has been made to estimate total numbers or perform spatial modelling of distribution from this data set. The relatively low number of observations prevented such an analysis. The present data will potentially be used for estimation of total numbers and distribution at a later stage, in case future surveys can supplement the data set.

Keywords: Coastal waterbirds number and distribution, moult, Lofoten, Vesterålen, aerial survey, line transect.

Layout: NERI Graphics Group, Silkeborg

Cover photo: Lofoten. Photo: Rasmus Due Nielsen.

Number of pages: 24

ISBN: 978-87-7073-172-0

Internet version: The report is available in electronic format (pdf) at NINA’s website http://www.seapop.no/no/publications/published/2009.html or at NERI's website http://www.dmu.dk/Pub/NINAreportLofoten.pdf

Contents

Summary 5

1 Introduction 6

2 Materials and Methods 7

3 Results 10 3.1 Divers Gaviadaae 11 3.2 Northern Fulmar Fulmarus glacialis 11 3.3 Northern Gannet Sula bassana 11 3.4 Cormorant sp. Phalacrocorax carbo/aristotelis 11 3.5 Grey Heron Ardea cinerea 11 3.6 Whooper Swan Cygnus cygnus 11 3.7 Greylag Goose Anser anser 12 3.8 Dabbling ducks Anatinae 12 3.9 Common Eider Somateria mollisima 13 3.10 Common Merganser Mergus merganser 14 3.11 Red-breasted Merganser Mergus serrator 15 3.12 Sea Ducks Merginae 15 3.13 Gulls and terns Laridae 16 3.14 Waders Charadiidae 19 3.15 Atlantic Puffin Fratercula arctica 20 3.16 Other Auks Alciidae 20 3.17 Other species 21

4 Discussion 22

5 References 23

National Environmental Research Institute

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5

Summary

The results of an aerial survey of coastal waterbirds in Lofoten and Vesterålen in August of 2009 are presented in this report. No prior aerial survey of moulting birds during late summer has been carried out in the area. Counts of breeding/overwintering birds have shown Lofoten to be very important for a number of bird species.

Most of the breeding birds had left the area in August of 2009. Puffins were only numerous south of Værøy though not nearly as abundant as during the breeding season. Gulls together with Cormorants sp. were the most commonly observed bird species distributed along all coastlines. They were found mainly on small rocky islands and shores.

No attempt has been made to estimate total numbers or perform spatial modelling of distribution from this data set. The relatively low number of observations prevented such an analysis. The present data will poten-tially be used for estimation of total numbers and distribution at a later stage, in case future surveys can supplement the data set.

6

1 Introduction

Lofoten and Vesterålen are two archipelagos situated in Northern Nor-way (figure 1 and 2) covering a total area of more than 4300 km2, Vesterålen being the largest (3100 km2). It consists of numerous islands, the largest being Hinnøya (Figure 1). The landscape is very diverse with many different habitats creating ideal conditions for a wide variety of birds. Most of the islands have rocky shores with steep coastlines al-though sandy beaches and wetland areas are relatively common. Some lowland areas are found scattered around the islands, especially on the island of Røst and some areas on the northern islands.

The Gulf Stream runs along the archipelagos creating relatively constant climate conditions including mild winters. High marine production cre-ates good conditions for spawning fish species (e.g. Herring Clupea harengus and Northeast Atlantic Cod Gadus morhua) which means con-stant sources of food for birds.

Lofoten and Vesterålen are very important breeding areas for seabirds and for wintering seabirds (Anker-Nilssen 2006). Numerous bird colo-nies are found around the islands and the single largest population of breeding Arctic Puffins in Norway is found on the island of Røst with one fourth of the total Norwegian population of 1.7 million breeding pairs (Anker-Nilssen & Aarvak 2009). The Røst Archipelago supports the highest density of breeding sea birds in all of mainland Europe all though numbers have been decreasing in recent years (Anker-Nilssen 2006).

Figure 1. Lofoten seen from the east 19 August 2009. View from the co-pilot seat of the survey aircraft.

7

2 Materials and Methods

The distribution of moulting birds along the coasts of the Lofoten- and Vesterålen Archipelago was investigated in august of 2009. Aerial sur-veys were undertaken on the 18th -and 19th of August 2009. 59 evenly dis-tributed transects along the islands were flown. The longest transect be-ing 36.2 km and the shortest 2 km. A total of 1100 km were flown on transect (Table 1). Distance between each transect line was 5 km’s.

Figure 2. An overview of the survey area with the flown tran-sects (grey lines). The most important site names are men-tioned.

500 km

BodøBodø

AndøyAndøy

GimsøyaGimsøya

RøstRøst

VærøyVærøy

MoskenesøyaMoskenesøya

VestvågøyVestvågøy

AndøyaAndøya

AustvågsøyaAustvågsøya

LangøyaLangøya

HadseløyaHadseløya

SortlandSortland

FlakstadøyaFlakstadøya

HinnøyaHinnøya

Lofoten

Vesterålen

VikbotnVikbotn

VestfjordVestfjord

HadselfjordenHadselfjorden

Gim

søys

traum

en

Gim

søys

traum

en

Bodø

Andøy

Gimsøya

Røst

Værøy

Moskenesøya

Vestvågøy

Andøya

Austvågsøya

Langøya

Hadseløya

Sortland

Flakstadøya

Hinnøya

Vikbotn

Vestfjord

Hadselfjorden

Gim

søys

traum

en

8

The aerial survey was conducted in a twin-engine Partenavia P68 Ob-server flown by Leif Petersen, Danish Air Survey. Two observers, one in the back and one in the front, counted birds on both sides of the plane. Observers on all transects were Rasmus Due Nielsen (NERI) and Morten Helberg, NINA.

Birds were counted in four bands the outer boundary being 1.5 km’s away from the plane (table 2). Clinometers (SILVA Clino Master) were used to place birds into the right transect bands. Bobble windows is in-stalled in the back of the plane to improve observation conditions for the observer sitting there. To each observation, exact time, information about species, number, band and behaviour were recorded directly onto a Dic-taphone (Phillips LFH 488) in the airplane.

All birds were identified down to species level in cases where this was possible. All observations of marine mammals were also registered. Transects were placed perpendicular on the coastline to increase the number of physical gradients (e.g. depth) crossed during each transect. The outer boundary of the transect lines was the 40 m isoclines, though in some cases transects continued into deeper water to make more even demarcations.

Transects were flown in an altitude of 250 feet (84 m) and with a speed of approximately 90 knots (160 km/h). Low flying speed and height in-creases the observers’ possibilities of positive identifications.

Human activities (e.g. fishing vessels, gill nets, aquacultures and hunt-ers) were recorded as these are expected to influence the distribution of water birds.

Information about wind, sun intensity and precipitation were recorded at the beginning of each transect and again if any changes happened dur-ing the transect. Strong wind or heavy precipitation can influence the ob-servers’ possibilities of finding and identifying birds.

Table 1. The dates and airports used during the Aerial Survey in Lofoten, August 2009. Individual transect numbers and their distance are also mentioned. * Ferry flights between Denmark and Norway.

Date Start End Transects Distance (km)

17/08/2009 Aarhus, AAR (DK) Bodø, BOO (N) Ferry* ---

18/08/2009 Bodø, BOO Bodø, BOO 1-30 493

19/08/2009 Bodø, BOO Bodø, BOO 31-59 607

20/08/2009 Bodø, BOO Aarhus, AAR Ferry* ---

Table 2. The transect band delimitation used during aerial surveys in Lofoten and Verstrålen in 2009. The distances/angles listed below are defined as the perpendicular distances/angles from the count route (90˚ being vertical and 0˚ being horizontal).

Transect band Delimitation (meters). Measured perpendicular on the flying route

Delimitation (degrees). Measured perpendicular on the flying route

A 44-163 60˚-25˚

B 164-432 25˚-10˚

C 433-1000 10˚-4˚

D 1001-1500 4˚-3˚

9

The endpoint of some transects were shortened, due to the rugged na-ture of the coastline. Short stretches of transects in small, narrow fjords were also avoided to minimize potential danger.

The weather was shifting but conditions were primarily good with alter-nating cloud cover and moderate winds. A few showers were recorded on the 19th of August, and some moderate winds (seastate 3) were re-corded on some of the transects furthest towards the west.

Dictaphone tapes containing observations from the individual transect flights were transcribed as soon as possible to increase the chances of finding and correcting any potential errors. The data from these present surveys were transcribed within two weeks after termination of the sur-veys.

A GPS (Trimle, GeoXT) logged points every five seconds on all transects with corresponding UTC times. Times of observations were correlated with the GPS-track file (Turbo Pascal) in order to make an ARCGIS point-theme.

10

3 Results

A total of 32 species of birds (table 3) were registered. All recorded spe-cies are described, quoting the total number of observed birds and with a brief description of their spatial distribution. The spatial distribution of the most abundant birds is illustrated with a thematic map. Only obser-vations done on transect are included (all observations of raptors are in-cluded, including those done off transect).

Table 3. Total numbers of observations and the total number of observed individuals of birds and marine mammals recorded during an aerial survey in the Lofoten/Vesterålen Archipelago’s in August of 2009.

Species Number of observations Total number of birds

Diver sp. 1 2

Red-throated Diver 2 3

Northern Fulmar 6 20

Northern Gannet 29 40

Cormorant sp. 182 3141

Grey Heron 8 30

Whooper Swan 10 73

Greylag Goose 18 224

Mallard 6 100

Eurasian Teal 2 36

Eurasian Wigeon 1 25

Long-tailed Duck 2 13

Common Eider 69 968

Velvet Scooter 1 6

Common Merganser 6 199

Red-breasted Merganser 10 99

White-tailed Eagle 16 19

Golden Eagle 2 3

Eurasian Oystercatcher 27 82

Eurasian Curlew 7 45

Arctic Skua 10 12

Common Gull 14 57

Herring Gull 419 1787

Lesser Black-backed Gull 3 4

Great Black-backed Gull 281 909

Kittiwake 54 88

Gull sp. 80 4234

Arctic/Common Tern 82 312

Auk/Common Murre 7 20

Common Murre 4 7

Black Guillemot 16 26

Atlantic Puffin 26 444

Raven 5 8

Harbour Porpoise 5 9

11

3.1 Divers Gaviadaae

Five divers were recorded. Of these three were identified as Red-throated Divers Gavia stellata and the remaining two were unidentified Red-throated/Black-throated Divers Gavia stellata/arctica. Both species breed on the archipelagos (Anker-Nilssen 2006).

3.2 Northern Fulmar Fulmarus glacialis

Only 20 Northern Fulmars were observed all to the west of the archi-pelagos. Birds were seen in numbers following fishing vessels off tran-sect during ferry flight of the northern tip of Andøya where the water depth drops dramatically close to the shore. Fulmars often aggregate close to fishing vessels where they can be found in large numbers.

3.3 Northern Gannet Sula bassana

A total of 40 Northern Gannets were observed west of islands primarily in open water just west of Hadselfjorden. The total breeding population on Lofoten/Vesterålen is stable though there are some differences in the placement of smaller colonies between years (Lorentsen & Christensen-Dalsgaard 2009).

3.4 Cormorant sp. Phalacrocorax carbo/aristotelis

The two species are treated in combination as positive identification to the species level is often very difficult. A total of 3141 cormorants sp. were observed (Figure 3). Both species breed on Lofoten and Vesterålen (Anker-Nilssen 2006).

Birds were primarily observed resting on rocks along the coastal line of-ten associating with mixed flocks of the larger gull species. Single birds were observed foraging or flying low over the open sea. In more occa-sions mixed groups of Cormorant and Shag was positively identified.

3.5 Grey Heron Ardea cinerea

A total of 30 Grey Herons were observed. Birds were observed in small flocks (up to 8 birds together) and single individuals primarily in areas with coastal meadows or in shallow bays.

3.6 Whooper Swan Cygnus cygnus

73 Whooper Swans were recorded, all of which were seen in the north-ern part on Andøya. All birds were observed close to coastline with the majority in shallow bays. Additional birds were seen on lakes off tran-sect.

12

3.7 Greylag Goose Anser anser

A total 224 Greylag Geese were observed (figure 4). Most birds (126) were seen in four flocks around Gimsøya. Another big flock was seen near the south-western tip of Langøya (45 birds).

3.8 Dabbling ducks Anatinae

Three species of dabbling duck were observed. Mallard Anas platyr-hunchos (100) Eurasian Teal Anas crecca (36) and Eurasian Wigeon Anas penelope (25).

Figure 3. The distribution of observed cormorants (Cormorant and Shag) on an aerial survey in August 2009. The figure shows all observations of cormorant, shag and unidentified cormo-rants.

Transects

Cormorant sp.

(n=3141)

1-9

10-25

26-40

41-100

101-220

500 km

13

3.9 Common Eider Somateria mollisima

A total of 968 birds were recorded. Eiders were observed in small num-bers along the entire coast line (figure 5). Only three flocks containing more than 50 birds were registered. Larger concentrations were found in the Röst Area (257) and north of Vikbotn (245).

Figure 4. The distribution of observed greylag geese on an aerial survey in August 2009.

Transects

Greylag Goose

(n=224)

2

3-7

8-10

11-20

21-51

500 km

14

3.10 Common Merganser Mergus merganser

A total of 199 birds in six flocks were recorded (figure 6). The majority of birds (170) were seen in Gimsøystraumen with flocks containing up to 70 birds.

Figure 5. The distribution of observed common eiders on an aerial survey in August 2009.

Transects

Common Eider

(n=968)

1-5

6-10

11-25

26-50

51-80

500 km

15

3.11 Red-breasted Merganser Mergus serrator

A total of 99 birds were registered with birds being more evenly distrib-uted over the Archipelagos (figure 7) compared with Common Mergan-ser. Two flocks containing 25 birds were observed; one in Gimsøystrau-men and one in Viksbotn.

3.12 Sea Ducks Merginae

Very few other diving ducks than the above mentioned ones were re-corded. Only Long-tailed Duck Clangula hyemalis (13) and Velvet Scoter Melanitta fusca (6) were recorded.

Figure 6. The distribution of observed common mergansers on an aerial survey in August 2009.

Transects

Common Merganser

(n=199)

4

5-7

8-18

19-40

41-70

500 km

16

3.13 Gulls and terns Laridae

Five species of gulls were observed with Herring Gull Larus argentatus (1787) and Great Black-backed Gull Larus marinus (909) being the most common and widespread. Common Gull Larus canus (57), Lesser Black-backed Gull Larus fuscus (4) and Kittywake Rissa tridactyla (88) were also registered.

Herring gulls (Figure 8) and Great Black-backed Gulls (Figure 9) were commonly observed over most of Lofoten but there was a tendency to-wards fewer birds on the western sides of Moskenesøya and Vestvågøya compared to the eastern side of the same islands, maybe due to harsher habitat on the western side. Larger aggregations of gulls were often found near harbours or fishing vessels, as well as on rocks and smaller islands.

Figure 7. The distribution of observed red-breasted mergan-sers on an aerial survey in Au-gust 2009.

Transects

Red-breasted Merganser

(n=99)

1

2-4

5-10

11-18

19-25

500 km

17

Figure 8. The distribution of observed herring gulls on an aerial survey in August 2009.

Transects

Herring gull

(n=1787)

1-3

4-12

13-25

26-45

46-60

500 km

18

An additional 4234 unidentified gulls Larus sp. mainly Herring Gulls or Great Black-backed Gulls were noted.

312 Unidentified Terns (Arctic/Common) Sterna paradisaea/hirundo were observed (Figure 10). The majority probably being Arctic Terns but posi-tive identification of the two species is very difficult from a plane, even under ideal conditions. Thus all observations are treated as unidentified Tern. Both species breed in Northern Norway, Arctic Tern though far outnumbering Common Tern (Haftorn 1971, seapop.no). The main part of the birds was observed in the inner parts of Hadselfjorden and in Vik-botn.

Figure 9. The distribution of observed great black-backed gulls on an aerial survey in Au-gust 2009.

Transects

Great Black-backed gull

(n=909)

1-2

3-7

8-15

16-25

26-40

500 km

19

3.14 Waders Charadiidae

Two species of waders were recorded, Eurasian Oystercatcher Haemato-pus ostragelus being the most numerous with 82 birds registered and Eurasian Curlew Numenius arquata with 45 birds. Both species breed on Lofoten and Vesterålen (Anker-Nilssen 2006).

Figure 10. The distribution of observed arctic/common terns on an aerial survey in August 2009.

Transects

Arctic/Common Tern

(n=312)

1-2

3-7

8-15

16-25

26-35

500 km

20

3.15 Atlantic Puffin Fratercula arctica

A total of 444 Atlantic Puffins were recorded (Figure 11), the main part of which were seen in the immediate vicinity of breeding colonies (Røst and Bleiksøy). Recent studies indicate a north-eastern bound migration of Atlantic Puffins in late summer/autumn (Anker-Nilssen & Aarvak 2009). This could explain the low numbers recorded during these August survey.

3.16 Other Auks Alciidae

Few alcidae were registered; Common Murre Uria aalge (7) and Black Guillemot Cepphus grylle (26). An additional 20 Unidentified Alcidae were noted with most if not all being Razorbill Alca torda or Common Murre.

Figure 11. The distribution of observed Atlantic puffins on an aerial survey in August 2009. Birds were concentrated at their breeding grounds.

Transects

Atlantic Puffin

1-2

3-5

6-10

11-100

101-300

500 km

21

3.17 Other species

White-tailed Eagle Haliaeetus albicilla was the most commonly registered raptor with 19 birds (Figure 12) most in Lofoten. In 2005 the breeding population of White-tailed Eagles in the Lofoten Archipelago alone to-talled 92 pairs (Anker-Nilssen 2006). Three Golden Eagles Aquila chrysae-tos were observed (figure 8) on two occasions, including a younger bird seeking food over a dump site. All observations of raptors including those seen off transect are included in the above-mentioned totals. Other birds included 12 Arctic Skuas Stercorarius parasiticus and 8 Ravens Cor-vus corax.

The only marine mammal registered was Harbour Porpoise Phocoena phocoena with a total of 9 animals.

Figure 12. The distribution of observed golden eagles/white-tailed eagles on an aerial survey in August 2009. All observations of raptors are shown including birds observed off transect.

Raptors

Golden Eagle (n=3)

White-tailed Eagle (n=19)

1

2

1

2

Transects

500 km

22

4 Discussion

Fewer birds than expected were recorded during the aerial survey in the Lofoten -and Vesterålen Archipelagos. Low numbers of Eiders and auks were recorded. Cormorants, Great Black-backed Gull and Herring Gull were all abundant.

The relatively few recordings of most species of birds prevented an esti-mation of total abundance and distribution from the observations. The use of the software “Distance Sampling” requires a minimum number of observations for such estimation to be successful. We assume that the observations of Cormorants and Shags could be suitable for abundance estimation, but since these are not target species for the survey we have decided not to attempt this.

The survey data were all collected using the Distance Sampling method, and with future data collected in the same way, these present data can be evaluated in combination with new data.

23

5 References

Anker-Nilssen, T. 2006. The Avifaunal value of the Lofoten Islands in a World Heritage perspective. – NINA Report 201. 23 pp.

Anker-Nilssen, T. & Aarvak, T. 2009. Satellite telemetry reveals post-breeding movements of Atlantic puffins Fratercula arctica from Røst, North Norway. Polar Biol (2009) 32: 1657-1664.

Haftorn, S. 1971. Norges fugler. Universitetsforlaget.

Lorentsen, S.-H & Christensen-Dalsgaard, S. 2009. The national monitor-ing programme for seabirds. Results up to and including the 2008 breed-ing season. NINA Report 439.

National Environmental Research Institute, NERI, is a part of Aarhus University.

NERI undertakes research, monitoring and consultancy

within environment and nature.

At NERI’s website www.neri.dk you’ll fi nd information regarding ongoing research and development projects.

Furthermore the website contains a database of publications including scientifi c articles, reports, conference contributions etc. produced by NERI staff members.

National Environmental Research InstituteDanmarks Miljøundersøgelser

NERIDMU

Further information: www.neri.dk

National Environmental Research Institute Management Frederiksborgvej 399 Department of Arctic Environment PO Box 358 Department of Atmospheric Environ ment DK-4000 Roskilde Department of Environmental Chemistry and Microbiology Denmark Department of Marine Ecology Tel: +45 4630 1200 Department of Policy Analysis Fax: +45 4630 1114 National Environmental Research Institute Department of Freshwater Ecology Vejlsøvej 25 Department of Terrestrial Ecology PO Box 314 DK-8600 Silkeborg Denmark Tel: +45 8920 1400 Fax: +45 8920 1414

National Environmental Research Institute Department of Wildlife Ecology and Biodiversity Grenåvej 14, Kalø DK-8410 Rønde Denmark Tel: +45 8920 1700 Fax: +45 8920 1514

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MOULTING BIRDS IN LOFOTEN AND VESTERÅLEN, AUGUST 2009Report commissioned by the Norwegian Institute for Nature Research (NINA)

The results of an aerial survey on Lofoten and Vesterålen in August of 2009 are presented in this report. No prior aerial survey of moulting birds during late summer has been carried out in the area. Counts of breeding/overwintering birds have shown Lofoten to be very important for a num-ber of bird species.

Most of the breeding birds had left the area in August of 2009. Puffi ns were only numerous south of Værøy though not nearly as abundant as during the breeding season. Gulls together with Cormorants sp. were the most com-monly observed bird species distributed along all coast-lines. They were found mainly on small rocky islands and shores.

No attempt has been made to estimate total numbers or perform spatial modelling of distribution from this data set. The relatively low number of observations prevented such an analysis. The present data will potentially be used for estimation of total numbers and distribution at a later stage, in case future surveys can supplement the data set.

ISBN: 978-87-7073-172-0