melanotus Craig, 1979 [C] Selasphorus rufus Kodric-Brown and Brown, 1978 [C] Gass and Lertzman, 1980 [C] Calypte anna Ewald and Carpenter, 1978 [E] Family Anatidae Nudds and Ankney, 1982 [C] Family Scolopacidae Myers et al., 1979b [C] Tryngites subruficollis Myers, 1980 [P, C] Calidris alba Myers et al., 1979a [C] Myers et al., 1981 [C] Pluvialis squatarola Turpie, 1995 [C] Catoptrophorus semipalmatus McNeil and Rompre, 1995 [C] Catharcta maccormicki Pietz, 1987 [C] Catharcta lonnbergi Pietz, 1987 [C] Stercorarius
The significance of kleptoparasitism during the breeding season in a colony of Arctic Skuas Stercorarius
parasiticus in Iceland.
But not all secondary consumers are mammals; the south polar skua or jaeger (Stercorarius
skua maccormicki, upper photo) can also act as one.
Nine species bred regularly on the island, probably in every year: Common Eider (Somateria mollissima), Northern Fulmar, Black-legged Kittiwake, Glaucous Gull, Parasitic Jaeger (Stercorarius
parasiticus), Thick-billed Mprre, Black Guillemot (Cepphus grylle), Common Raven (Corvus corax), and Snow Bunting (Plectrophenax nivalis).
parasiticus) attempted to steal prey from returning parent birds in flight.
Despite numerous indications that, lemmings had been abundant under the snow (many winter nests, extensive traces of grazing, and large amounts of lemming feces), lemming densities were rather low after snow melt, and the lemming specialists such as snowy owls (Bubo scandiaca), rough-legged buzzard (Buteo lagopus) and pomarine skua (Stercorarius
pomarinus--one unsuccessful nest) were not breeding in summer 2008 (Popov, 2009).
Evidence of breeding had been found in earlier expeditions to the site for Baird's sandpiper (Calidris bairdii), long-tailed duck (Clangula hyemalis), parasitic jaeger (Stercorarius
parasitica), red knot (Calidris canutus), and rock ptarmigan (Lagopus mutus) (Table 2), but during our seasons of study, we could not confirm that these species still bred there.
Glaucous gulls (Lams hyper-boreus) and the three jaeger species (Stercorarius
We have no measure of predation or pathogen risk along the Asiatic continental route, but predation risk in western Alaska appears to decline later in the season as parasitic jaegers (Stercorarius
parasiticus) and other potential avian predators depart (Gill et al., 2009; R.E.
Some seabirds (e.g., skuas, Stercorarius
spp., and frigatebirds, Fregata spp.) specialize in kleptoparasitism and rely on piracy for most of their energy acquisition.
hyperboreus), and parasitic jaegers (Stercorarius
parasiticus), although in some years arctic foxes (Alopex lagopus) were important nest predators.
Ecology of the long-tailed skua (Stercorarius
longicaudus Vieillot, 1819) at Scoresby Sund, East Greenland.