WatchList Species Account
for Ivory Gull (Pagophila eburnea)
 |
| Photo: USFWS |
This circumpolar species breeds in northern
Canada, Greenland, and in archipelagos north of the Russian
Federation. It winters just south of the Arctic pack ice and
appears as a vagrant in western Europe and Japan and China.
The Ivory Gull is associated with ice edges and pack ice near
islands where there is open water, nests colonially on cliffs
and rocky islands and the sides of steep limestone ridges
that may be as far as 35 miles from the coast and at an elevation
as high as 6,000 feet. It occasionally nests in colonies with
other seabirds.
During the nonbreeding season, the bird
occurs solitarily or in small flocks. Though fish and invertebrates
form the bulk of its diet, like other gulls it is a highly
opportunistic feeder, scavenging faeces and carrion of seals
killed by polar bears, offal from whales, walruses and seals,
and garbage scavenged near Arctic settlements; in fact it
is known to follow polar bears and Inuit hunters to scavange
food. Most predation of Ivory Gulls is on eggs and young at
the breeding colonies, accounting for the choice of remote
sites for nesting.
The main predator is the arctic fox, which
sometimes takes eggs and young from entire colonies; other
predators include polar bear, Parasitic and Long-tailed jaegers,
Snowy Owl, and Glaucous and Thayer’s gulls. Gyrfalcons
are known to prey on adults. Long-standing colonies have a
fertilizing effect that results in a relatively highly-developed
vascular flora. Chicks are fed largely on small fish and crustaceans,
caught at sea rather than near the nest. As for conservation,
the first need is to get a better idea of the number of colonies
and their sizes in the North American population. Also important
is to determine the extent to which the species relies on
one or two main wintering areas, so an international plan
of protection can be developed for this circumpolar species.
|