|Scientific Name:||Alca torda|
|Species Authority:||Linnaeus, 1758|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
|Range Description:||Their breeding habitat is islands, rocky shores and cliffs on northern Atlantic coasts, in eastern North America as far south as Maine (USA), and in western Europe from northwestern Russia to northern France. North American birds migrate offshore and south, ranging from the Grand Banks of Newfoundland (Canada) to New England (USA). Eurasian birds also winter at sea, with some moving south as far as the western Mediterranean.|
Native:Belgium; Canada; Denmark; Estonia; Faroe Islands; Finland; France; Germany; Gibraltar; Greenland; Iceland; Ireland; Latvia; Lithuania; Morocco; Netherlands; Norway; Poland; Portugal; Russian Federation; Saint Pierre and Miquelon; Spain; Svalbard and Jan Mayen; Sweden; United Kingdom; United States
Vagrant:Algeria; Austria; Croatia; Czech Republic; Egypt; Hungary; Italy; Japan; Malta; Mauritania; Montenegro; Serbia (Serbia); Slovenia; Tunisia
|Range Map:||Click here to open the map viewer and explore range.|
|Habitat and Ecology:||Behaviour Razorbills are pursuit divers that propel themselves through the water with their wings. They are capable of diving to 120m depth, but mostly forage nearer the surface. They spend most of their lives at sea, only arriving ashore to reproduce. During the prelaying period, they never spend a night in the nest, and even after the egg is laid, only one parent remains in the nest. Diet They are known to consume krill, amongst other prey. In the Bay of Fundy, Canada, 76% of Razorbill stomachs contained krill (Huettman et al 2005). Foraging range This species has been described as coastal rather than pelagic (Huettman et al 2005), and birds tend to be concentrated within 10 km of the shore (BirdLife International 2000, Huettman et al 2005). At Flamborough Head, UK, maximum densities of birds were observed at under 1 km from the colony and 6 - 28 km away from the colony (BirdLife International 2000). Birds were seen up to 25 km from the Pembrokeshire Islands in 1992, with the highest mean density within 5 km, whereas in June 1990, birds were found up to 45 km away (albeit in low numbers beyond 25km) with the highest densities within 10 km (BirdLife International 2000). At the Isle of May during chick rearing, radio-tracking revealed that 91% of birds foraged at over 10 km from the colony, although transect counts showed a density maximum within 5 km of the colony (Wanless et al. 1998). Another area of high bird density was located 35km away over the Wee Bankie (Wanless et al. 1998). Razorbills breeding at St Kilda foraged at the Whale Rock Bank, 38 km away, although a high proportion of the breeding population appeared to be foraging within 5 km of the island. At North Rona the maximum feeding range was 15 km. Razorbills are probably capable of diving to at least 120 m. Analysis of surveys of distribution at sea indicated that very few were present in waters deeper than 200 m during the breeding season, with the greatest abundance found at depths less than 100 m. At the Isle of May, they foraged preferentially in shallow waters (less than 30 m deep) (Wanless et al. 1998). The same individuals used several widely-separated feeding areas on different days and even on the same day (Wanless et al. 1998). Razorbills occur in high numbers around fronts, as around the Irish Sea Front during autumn. On the Isle of May they were found to be associated with both tidal fronts and the presence of the Clyde front during the early breeding season (BirdLife International 2000). They were also highly concentrated at an offshore bank near St Kilda (Leaper et al. 1988, BirdLife International 2000). In winter in the Bay of Fundy, Canada, they tended to forage within tidal upwelling zones (Huettman et al 2005). A significant proportion of Razorbills breeding in North America spend at least part of the winter in the outer Bay of Fundy and in its coastal zone (i.e. less than 8km offshore) (Huettman et al 2005). It is likely that, in winter, the species gathers in relatively small areas where predictable concentrations of prey occur (Huettman et al 2005).|
BirdLife International. 2000. The Development of Boundary Selection Criteria for the Extension of Breeding Seabird Special Protection Areas into the Marine Environment. OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic. Vlissingen (Flushing).
del Hoyo, J.; Elliott, A.; Sargatal, J. 1996. Handbook of the Birds of the World, vol. 3: Hoatzin to Auks. Lynx Edicions, Barcelona, Spain.
Huettman, F., Diamond, A.W., Dalzell, B. and Macintosh, K. 2005. Winter distribution, ecology and movements of razorbills Alca torda and other auks in the outer Bay of Fundy, eastern Canada. Marine Ornithology 33: 161-171.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Leaper, G.M., Webb, A., Benn, S., Prendergast, H.D.V., Tasker, M.L. and Schofield, R. 1988. Seabird studies around St Kilda, June 1987. Nature Conservancy Council, Peterborough, UK.
Sandvik, H.; Erikstad, K. E;, Barrett, R. T.; Yoccoz, N. G. 2005. The effect of climate on adult survival in five species of North Atlantic seabirds. Journal of Animal Ecology 74: 817-831.
Wanless, S., Harris, M.P. and Greenstreet, S.P.R. 1998. Summer sandeel consumption by seabirds breeding in the Firth of Forth, south-east Scotland. ICES Journal of Marine Science 55(6): 1141-1151.
|Citation:||BirdLife International 2012. Alca torda. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 22 May 2013.|
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