Kaj Kampp

Seabirds utilizing the Northeast Water polynya

Abstract A small seabird community depends on the resources of the Northeast Water (NEW) polynya. In spring, at least 1000 King Eiders and 2500 Common Eiders form pre-breeding congregations at Ob Bank before dispersing in mid June to breeding areas. The most abundant species is the Fulmar, which breeds in six colonies with a total of 2550 “apparently occupied sites”, corresponding to approx. 1475 active pairs in 1993. Kittiwakes occupied almost 900 sites at Mallemukfjeld, with an estimated 733 breeding pairs. The entire NEW area probably holds 400–500 pairs of Ivory Gulls, and about 500 individuals were associated with a colony on Henrik Kroyer Holme; this is one of the worlds largest known colonies. Sabines Gulls breed at the same islands and on Kilen (approx. 50 pairs in each place). Small colonies (total less than 1000 birds) of Arctic Terns are distributed along the edge of the polynya, with the largest colony of about 100 pairs on Henrik Kroyer Holme. The Black Guillemot is the only breeding auk species ( Apart from the benthic foraging eiders and the Black Guillemot, the seabird community of NEW consists of surface feeders—Fulmars and gulls—dependent on small fish and zooplankton. During their stay in the NEW area, the five most abundant surface feeders will annually consume approximately 243,000 kg (wet weight) of food, of which the Fulmars alone take 67%. Food demand in relation to area of open water in the polynya is highest in spring (approx. 0.2 kg/km 2 ), which is

Measurements of Diving Depth in Dovekies (Alle alle)

Diving seabirds have a three-dimensional foraging habitat, and maximum diving depth is important in defining habitat availability for each species. Therefore, measurements of dive depths and profiles are significant components in many studies of seabird foraging ecology (Burger 1991, Burger et al. 1993, Wilson 1995, Gaston and Jones 1998). The Dovekie (Alle alle) is the most abundant seabird that breeds in the high-arctic region of the Atlantic, where it feeds chiefly on small zooplankton (Roby et al. 1981, Bradstreet 1982) that are caught by wing-propelled iving. The actual diving depths reached by foraging Dovekies have not been measured, and apart from indirect evidence, such as dive duration or projec-

Breeding density and population of little auks (Alle alle) in a Northwest Greenland colony

Abstract The little auk population of the Thule district in Greenland is generally believed to be the largest anywhere and to comprise more than half of the world population, although published numbers have largely been conjectural. In 1996/1997 we estimated breeding density of little auks at Hakluyt Island in this district by colour-marking a number of birds in three study plots and subsequently counting marked and unmarked birds present in the plots. The density estimate considered most representative of the colony was 1.8 birds/m2 or 0.73 pairs/m2 (±7%). From surveys of the inhabitated area of the scree slopes, this density implies a total little auk population for the island of 130,000 pairs. An extrapolation to the entire Thule district suggests a population in the area of at least 15 million pairs, which is in general agreement with previously published assumptions.

Summer distribution of seabirds in the North-East Water polynya, Greenland

Abstract The distribution at sea of seabirds was studied in the North-East Water (NEW) polynya, Greenland, during transect counts in the summers of 1991, 1992 and 1993 on board the ice-breaking RVs Polarstern and Polar Sea . Data collected within the polynya ‘box’ (78–82°N; 5–18°W) concern observations of 8000 birds counted during 1350 half-hour counts. Distribution is presented as density (N/km 2 ) and calculated daily food intake. Five bird species were selected for discussion, representing more than 95% of the total numbers encountered: Fulmar ( Fulmarus glacialis ), Ivory Gull ( Pagophila eburnea ), Kittiwake ( Rissa tridactyla ), Glaucous Gull ( Larus hyperboreus ) and Rosss Gull ( Rhodostethia rosea ). For these species, densities are comparable in the NE Greenland polynya and in other European Arctic seas. The main difference is the absence in NEW of the species playing the main role in Arctic seas: Brunnichs Guillemot ( Uria lomvia ) and Little Auk ( Alle alle ). In the absence of fish-eating birds and of birds consuming zooplankton in the water column, the NEW polynya ecosystem is thus dominated by surface feeders and, closer to the coast, by benthic feeders like eiders, Somateria mollissima and S. spectabilis , and walrus, Odobenus rosmarus . The density and daily food intake for all seabirds are one order of magnitude lower in the polynya than in the Arctic seas. The distribution and abundance of seabirds in the NEW polynya seems to reflect a very low density of pelagic fish and Zooplankton in the water column, while Zooplankton must be present at ‘normal’ concentrations in the upper layer.

The Breeding Association of Red Phalaropes with Arctic Terns: Response to a Redistribution of Terns in a Major Greenland Colony

Abstract The Red Phalarope (Phalaropus fulicarius) is a rare species in west Greenland, where it generally breeds on islands in association with the Arctic Tern (Sterna paradisaea). The strength of this association was confirmed on the archipelago of Grønne Ejland, the largest tern colony in Greenland, where Arctic Terns inhabited all four major islands until 15 years ago, but now have abandoned two of them; the Red Phalarope left the same two islands after a few years, but not the islands still inhabited by terns. The terns apparently disappeared from the two islands due to the presence of Arctic Foxes (Alopex lagopus) over several years. The disappearance of the Red Phalarope could have been a response to the absence of breeding terns, or could have happened as a direct result of predation and disturbance from foxes. The Red-necked Phalarope (P. lobatus), however, still breeds on the islands abandoned by the terns. It might be that the Red Phalarope is more vulnerable to fox predation than the Red-necked Phalarope, which may partly explain why the former of the two species in west Greenland breeds only in tern colonies on islands, whereas the latter is widely distributed, including inland areas.