Population sizes
Knowledge about the size of seabird populations is important, in part, in order to evaluate the conservation value and vulnerability of the populations. Species that occur in large numbers with a wide distribution are often more robust against negative influences than species that are few in number.
Four main questions
SEAPOP focuses on four population numbers:
- How many seabirds breed in Norway?
- How many seabirds overwinter along the coast?
- How many sea ducks moult (change feathers) along the coast in autumn?
- How many seabirds do we find on the open sea during the different seasons?
The mapping of birds in the breeding season is used to calculate population sizes of the seabirds. The number of nesting pairs at a given breeding locality is counted, and these numbers are summed up over larger areas. This type of mapping is laborious, and in principle is done only every tenth year. We therefore use data from the nearest monitoring sites to adjust and update the population numbers for every individual breeding locality.
Photo: Kjetil Schjølberg
Population numbers only reflect breeding birds
It is important to note that the numbers represent the number of breeding pairs, and therefore the non-breeding portion of the population is not taken into account. This principally includes immature birds and adult birds that choose not to breed.
The population numbers give an updated picture of the abundance of the different species in Norwegian areas. The numbers are used in many connections, and they explain which seabird species dominate the Norwegian sea areas and which species Norway has a special management responsibility for.
Species | Norwegian mainland | Jan Mayen | Svalbard | Norway | National | Europe | Share in Norway | |||||
North Sea-Skagerrak | Norwegian Sea | Barents Sea | Total | Bjørnøya | Other areas | Total | ||||||
Northern Fulmar ¹ | 600 | 7 500 | 0 | 8 000 | > 170 000 | 30 000 | < 1 mill. | < 1 mill. | ± 1 mill. | ± 20% | 3 000 000 | 33% |
European Storm-Petrel¹ | > 100 | > 1 000 | > 100 | < 10 000 | 0 | 0 | 0 | 0 | < 10 000 | < 1% | 690 000 | 1% |
Leach's Storm-Petrel¹ | > 10 | > 100 | 0 | < 1 000 | 0 | 0 | 0 | 0 | < 1 000 | < 1% | 150 000 | 1% |
Northern Gannet | 0 | 3 600 | 2 100 | 5 700 | 0 | > 10 | 0 | 10 | 5 700 | < 1% | 300 000 | 2% |
Great Cormorant² | 2 500 | 13 500 | 5 500 | 21 000 | 0 | 0 | 0 | 0 | 21 000 | < 1% | 45 000 | 41% |
European Shag | 14 000 | 9 000 | 5 000 | 28 000 | 0 | 0 | 0 | 0 | 28 000 | 1% | 81 000 | 35% |
Common Eider | 37 000 | 41 000 | 9 000 | 87 000 | < 200 | 100 | 17 000 | 17 000 | 104 000 | 2% | 2 000 000 | 5% |
King Eider | 0 | 0 | 0 | 0 | 0 | 0 | 500 | 500 | 500 | < 1% | 500 | 100% |
Great Skua | < 10 | 90 | 20 | > 110 | < 50 | 750 | 250 | 1 000 | 1 100 | < 1% | 16 000 | 7% |
Arctic Skua³ | < 300 | < 1 000 | < 1 000 | 2 000 | < 50 | 100 | > 900 | 1 000 | 3 000 | < 1% | 17 500 | 17% |
Common Tern¹ | 7 000 | < 3 000 | 1 000 | < 11 000 | 0 | 0 | 0 | 0 | < 11 000 | < 1% | 300 000 | 4% |
Arctic Tern¹ | 5 000 | 20 000 | 4 000 | 29 000 | < 1 000 | < 100 | < 10 000 | < 10 000 | < 40 000 | 1% | 750 000 | 5% |
Mew Gull³ | 5 500 | 75 000 | 10 000 | 90 000 | < 5 | < 5 | 0 | < 5 | 90 000 | 2% | 500 000 | 18% |
Lesser Black-Backed Gull | 21 500 | 6 500 | < 100 | 28 000 | < 50 | < 5 | 0 | < 5 | 28 000 | 1% | 180 000 | 16% |
Herring Gull | 19 000 | 42 000 | 11 500 | 72 000 | < 5 | 0 | 0 | < 5 | 72 000 | % | 850 000 | 8% |
Glaucous Gull | 0 | 0 | 0 | 0 | > 200 | 400 | 3 600 | 4 000 | 4 000 | < 1% | 21 500 | 20% |
Great Black-Backed Gull | 8 500 | 30 000 | 4 500 | 43 000 | < 40 | 20 | 80 | 100 | 43 000 | 1% | 120 000 | 36% |
Black-legged Kittiwake | 6 000 | 44 000 | 37 000 | 87 000 | < 10 000 | 135 000 | 109 000 | 245 000 | 340 000 | 6% | 2 500 000 | 14% |
Ivory Gull | 0 | 0 | 0 | 0 | 0 | 0 | 2 000 | 2 000 | 2 000 | < 1% | 2 000 | 100% |
Common Guillemot | 50 | 2 600 | 14 000 | 17 000 | < 1 000 | 132 000 | 100 | 132 000 | 150 000 | 3% | 2 900 000 | 5% |
Brünnich's Guillemot | 0 | 0 | < 100 | < 100 | > 110 000 | 95 000 | 520 000 | 615 000 | 725 000 | 13% | 1 000 000 | 73% |
Razorbill | 300 | < 10 000 | < 45 000 | < 55 000 | < 100 | 100 | 20 | 120 | 55 000 | 1% | 500 000 | 11% |
Little Auk¹ | 0 | 0 | 0 | 0 | < 100 000 | ± 50 000 | > 1 000 000 | > 1 000 000 | > 1 000 000 | ± 20% | > 1 000 000 | < 100% |
Black Guillemot 4 | < 400 | 15 000 | 20 000 | 35 000 | < 1 000 | < 1 000 | 19 000 | 20 000 | 55 000 | 1% | 200 000 | 28% |
Atlantic Puffin | 5 000 | 553 000 | 907 000 | 1 465 000 | < 5 000 | < 1 000 | 9 000 | < 10 000 | 1 500 000 | 27% | 5 500 000 | 27% |
Total | 133 000 | 875 000 | 1 075 000 | 2 100 000 | 400 000 | 440 000 | < 2 500 000 | 3 000 000 | 5 500 000 | 100% | 23 000 000 | 24% |
- Insufficient grounds for good population estimates for this species.
- The numbers for Europe and the share in Norway apply to the subspecies P. c. carbo, which breeds in Mid-Norway og North-Norway.
- Applies only to the population breeding along the coast. The inland population innlandet has not been assessed.
- The species demands special methodology for assessment, and good monitoring sites are lacking. Therefore, the estimate has not been updated since Barrett et al. (2006; Atlantic Seabirds).