The Davis Strait - DCE - Nationalt Center for Miljø og Energi

Common eider, Somateria mollissima
This duck is closely associated with the marine environment. It breeds both
dispersed and in colonies on low islands and feeds in shallow coastal waters
throughout the assessment area (Fig. 4.7.1).
Males assemble in moulting concentrations in remote fjords and archipelagos
when the females have brooded the eggs for some time. Females (failed
breeders) follow the males somewhat later and most birds moult within 100
km from the breeding site (Mosbech et al. 2006b). The flight feathers are
moulted simultaneously, which means that the birds become flightless for
about three weeks. After moulting the eiders migrate to wintering areas in
the open water region of Southwest Greenland (Lyngs 2003, Mosbech et al.
2007).
Total number of breeding birds in the assessment area is unknown, but
numbers probably amount to some thousand pairs (L. M. Rasmussen, pers.
comm.). The population declined considerably during the 1900s due to nonsustainable
harvest (Gilliland et al. 2009). But recently, after hunting in the
spring was prohibited, population recovery has been evident in the district
of Ilulissat and Upernavik, where active management and monitoring using
local stakeholders has been applied. An annual population increase of ∼15%
has recently been estimated for these breeding areas (Merkel 2008, 2010a).
Recent surveys in the central part of the assessment area indicated a similar
population increase (Rasmussen 2010, 2011).
The common eider population in West Greenland until recently had an unfavourable
conservation status due to the decline. It was therefore listed as
‘Vulnerable’ (VU) on the Greenland Red List (Boertmann 2007). However,
this status now seems out-dated.
Breeding colonies, moulting areas and staging areas during migration and
wintering are sensitive, as large number of birds may stay on the water in
such areas. Especially during winter, the density of common eiders is high
in the coastal zone of the assessment area (Fig. 4.7.6), as large numbers of
breeding birds from Northwest Greenland and eastern Canada spend the
winter in Southwest Greenland (Lyngs 2003, Mosbech et al. 2006b). In 1999
the winter population of common eiders was estimated to 460,000 birds in
Southwest Greenland, of which a large proportion occurred within the assessment
area (Merkel et al. 2002). Presumably the winter population has increased
considerably since then. Particularly the fjords and bays around
Nuuk are important wintering areas (Merkel et al. 2002, Blicher et al. 2011).
103