Hvitkinngås på vårtrekk

3 hekkebestander:

Russisk / Baltisk :

420 000 ind.

------------------Grønlandsk:

55 000 ind.

------------------

Svalbard:

29 000 ind.

Trekkruter på våren

Vesterålen

Helgeland

Fenologi

SVALBARD

HELGELAND/ BJØRNØYAVESTERÅLEN

SOLWAY SOLWAY

J F M A M J J A S O N D

Noen fakta:

• Første gjess ankommer i siste halvdel av april (normaltrundt 20. april) , de fleste har reist videre til Svalbard islutten av mai (normalt rundt 20. mai). Enkelte individer erobservert på Helgeland så seint som midten av juni.

•Ringmerket individer raster på Helgeland i gjennomsnittca. 11 – 14 dager.

•Noen er bare sett en gang, mens andre har oppholdt seg påHelgeland i inntil 23 dager.

•Gjessene bruker ca. 24 – 36 timer å fly fra Skottland –Helgeland uten motvind.

0

5000

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15000

20000

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35000

58

61

64

67

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79

82

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88

91

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97

00

03

06

år

antall

Rasteplasser på vårtrekk

1001+

501-1000

1-500

1975-82 og 1983-92 1993 - 2003

Utviklingen i antall hvitkinngjess i 2 kommuner på Helgeland 1992 - 2007

Vega kommune

Herøy kommune

0

200

400

600

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1400

199219931994

199519961997

1998199920002001

200220032004

200520062007

Hysvær Lånan Vallsjø

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3500

1992

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2001

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Husvær Brasøy Tenna S-. & N. Herøy

Utviklingen i antall hvitkinngjess i Vesterålen 1992 - 2007

050010001500200025003000350040004500

199219931994

199519961997

1998199920002001

200220032004

200520062007

Sortland Andøya

Ringmerking

0% 20% 40% 60% 80% 100%

Vallsjø

Hysvær

Lånan

Sandvær

Tenna & Herøy

Selvær

Sortland

Andøya

KO

SA

DA

NO

DU

Percentage composition of Barnacle geese from various ringing areas on Svalbard seen atsites along the Norwegian coast. Ring resightings are based on observations in the period1994–2001 except for Selvær (data from 2002). Staging sites are arranged from Vallsjø (Vega)in the south to Andøya in the north.

KO = Kongsfjorden, SA = Sassendalen, DA = Daudmannsøyra, NO = Nordenskiöldskysten,

DU = Dunøyane & Isøyane

Bruk av satellittsendere

Kart over deler av Helgeland som viser for-flytningene våren 2006 til tohvitkinngås hanner utstyrt med satellittsendere. ©The Wildfowl & Wetlands Trust.

vår 2007

The onset of spring and timing of migration in two arctic nesting goosepopulations

Tombre, I. M., Høgda, K.A., Madsen, J. Griffin, L.R., Kuijken, E., Shimmings, P., Rees, E. &Verscheure C.

(manuscript submitted Journal of Avian Biology )

An earlier onset of spring has beenrecorded for many parts of Eurasia inrecent decades. This has consequencesfor migratory species, not only inaffecting the conditions encountered onreaching migratory sites, but for theregulation of the timing of migrationwhere decisions to migrate areinfluenced by local environmentalvariables.

Where geese can use spring conditions at one site as an indicator of theconditions they might encounter at the next, they have respondedquickly to the advancement of spring, whereas in a situation where theycannot cue, they have not yet responded, despite the advancement ofspring in the spring staging area.

We examined the timing of spring migration for two arctic goose populations, which bothbreed on Svalbard:

The barnacle goose(Branta leucopsis)Study period: 1982 − 2003

The pink-footed goose(Anser brachyrhynchus)Study period: 1990 − 2003

The satellite derived Normalised Difference Vegetation Index (NDVI) was used to express the onset of springfor (A) the pink-footed goose and (B) the barnacle goose. The trend for an earlier onset of spring in more recentyears was significant for Jutland, Helgeland and the Solway Firth (* = p<0.05). Dates are given as Julian days.

0

20

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60

80

100

120

140

160

180

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002Ju

lian

day

Flanders (ns, Y=105-0.71X)

Jutland (* , Y=126-1.35X)

Trøndelag (ns, Y=133-0.38X)

Vesterålen (ns, Y=145+0.11X)

A)

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20

40

60

80

100

120

140

160

180

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Jul

ian

day

Helgeland (* , Y=136-0.53X)

Solway Firth (* , Y=118-0.88X)

B)

Pink-footed geese use several sites during migration, ranging from the southernmost winteringareas in Belgium to two spring staging areas in Norway, and distances between sites used along theflyway are relatively short. There was a positive correlation in the onset of spring betweenneighbouring sites, and the geese migrated earlier in early springs. Barnacle geese, on the otherhand, have a long overseas crossing from their wintering grounds in Britain to spring staging areasin Norway, and no relationship was found in the onset of spring between their wintering and springstaging sites. The only parameter found to influence departure from the wintering site was thespring conditions defined by the North Atlantic Oscillation (NAO), with geese departingsignificantly earlier when April was wet and mild.

Ekskrementtellinger i områder med og uten skremmebånd

0

1

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6

med bånd uten bånd

eksk

rem

ent p

r. m

2

n = 321

n = 208

Effekt av skremmebånd

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4 5 6 7

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Spring Summer Autumn

wei

ght (

g)

MalesFemales

Takk:Fylkesmannen i Nordland, miljøvernavdelingen, Herøy kommuneog Direktoratet for naturforvaltning for økonomiske støtte.

Takk til alle som har deltatt i feltarbeidet, og bidratt medopplysninger. Uten dere skulle vi ikke haviste så mye om hvitkinngåsa!