Eider (Somateria mollissima) Science Article 1 abstract We compared the feeding behaviour of lone tenders, multi-female tenders and postbreeding, non-tending eider females Somateria mollissima in the northern Baltic. Few prey species are available for eiders in the Baltic; in the non-breeding season adults prefer blue mussels Mytilus edulis, whereas small ducklings feed primarily on gammarids […]
Category: Anatidae
Variation in egg size of Common Eiders
Eider (Somateria mollissima) Science Article 4 abstract Egg size of Eiders Somateria mollissima was studied in the colony on Vlieland, The Netherlands, during six consecutive years. Mean length and breadth of 2476 eggs was 77.84 and 51.25 mm, respectively. Mean volume measured of 1882 of these eggs was 104.03 cm-3. A large variation in egg […]
Low costs of salt turnover in Common Eiders Somateria mollissima
Eider (Somateria mollissima) Science Article 5 abstract The energetic costs of salt turnover were measured in Common Eiders Somateria mollissima by respirometry. Rates of salt intake in the field were estimated from salt content of their chief prey, the mussel Mytilus edulis. Metabolic rate in Eiders increases in response to salt intake and may double […]
Factors affecting the bag size of the common eider Somateria mollissimain Denmark, 1980-2000
Eider (Somateria mollissima) Science Article 2 abstract Based on data compiled from the official Danish Bag Record and from the annual wing surveys of waterfowl, analyses of long-term trends in the bag of common eiders Somateria mollissimawere performed for the period 1958-2000, while more detailed analyses of factors affecting bag size were made for the […]
Egyptian Geese Alopochen aegyptiacus moulting on Dassen Island, South Africa
Egyptian Goose (Alopochen aegyptiacus) Science Article 1 abstract Egyptian Geese have increased in numbers in the Western Cape in recent decades, and they are considered agricultural pests in the Swartland region, the grain-producing area on the mainland adjacent to Dassen Island (Hockey et al. 1989). It is possible that traditional moult sites on the mainland […]
Distribution and behaviour of Common Scoter Melanitta nigra relative to prey resources and environmental parameters
Common Scoter (Melanitta nigra) Science Article 1 abstract Offshore wind farms are proposed around the coast of the UK and elsewhere in Europe. These sites tend to be located in shallow coastal waters that often coincide with areas used by over-wintering Common Scoter Melanitta nigra. A large-scale study was undertaken to ascertain the relationship of […]
Seasonal Enumeration of Fecal Coliform Bacteria from the Feces of Ring-Billed Gulls (Larus delawarensis) and Canada Geese (Branta canadensis)
Canada Goose (Branta canadensis) Science Article 1 abstract Water suppliers have often implicated roosting birds for fecal contamination of their surface waters. Geese and gulls have been the primary targets of this blame although literature documenting the fecal coliform content of these birds is quite limited. To determine the actual fecal coliform concentrations of these […]
Parasitic egg laying in canvasbacks: frequency, success, and individual behavior.
Canvasback (Aythya valisineria) Science Article 1 abstract Time-lapse photography and frequent nest checks conducted at Canvasback (Aythya valisineria) nests revealed a high frequency of intraspecific parasitic egg laying. At least 36% of completed Canvasback clutches were parasitized by other Canvasbacks, and at least 9.7% of all Canvasback eggs were laid parasitically during the three-year study. […]
Dark-bellied Brent Geese Branta bernicla bernicla forego breeding when Arctic foxes Alopex lagopus are present during nest initiation
Brant Goose (Branta bernicla) Science Article 8 abstract In an area north of the Pyasina delta in Taimyr (Russia), nest distribution, nest initiation and breeding success of Brent Geese Branta bernicla bernicla were studied in six successive summer seasons from 1990-1995 in relation to lemming and Arctic Fox Alopex lagopus abundance. Lemming abundance conformed to […]
The significance of female body stores for egg laying and incubation in Dark-bellied Brent Geese Branta bernicla bernicla
Brant Goose (Branta bernicla) Science Article 10 abstract The probability of successful breeding by Brent geese in the Arctic appears to be positively correlated with the mass of females when they depart from spring staging areas in North-western Europe. To clarify the mechanism behind this relationship we investigated the significance of flown-in female body stores […]