WatchList Species Account for Bristle-thighed Curlew
(Numenius tahitiensis)
Qualifies for
the list as a Declining Yellow List Species
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Photo: Bill Hubick |
The Bristle-thighed Curlew breeds only
in two remote areas on the tundra of western
Alaska, on the lower Yukon River and the central Seward Peninsula. It nests in dwarf-shrub meadows of several types;
these predominate at both nesting areas.
This species is a long-distance transoceanic migrant, making non-stop
flights of some 2,500 miles over the Pacific Ocean. During migration
they stage in the Yukon Delta on a mosaic of tundra and
meadows, roosting at night in shallow
brackish ponds.
The species winters on atolls and small
islands in Oceania, though some overwinter on the main Hawaiian
islands. In winter the birds use a wide variety of
habitats on islands; these include tital mudflats, marshy
areas, beaches, open areas away from the shorline, and airport
runways.
Insects and spiders are the main foods
during breeding, along with fruits and flowers of shrubs;
in winter the birds are opportunistic and feed on intertidal
and terrestrial insects, seabird eggs and young, carrion,
lizards, rodents, and fruits. The bird has been observed using
a stone to break seabird eggs.
Surveys from 1988-1992 on the breeding
areas revealed about 3,200 breeding pairs. During winter about
800 birds were estimated to winter in the Northwestern Hawaiian
Islands. The birds have been shot or trapped for food both
in Alaska and on the wintering grounds, where harvest is thought
to be much lower than in the past. Habitat modification on
wintering grounds is severe in parts of its range, and use
of off-road vehicles associated with mining continue to degrade
habitat on the Seward Peninsula, site of one of its two Alaskan
breeding grounds.
These curlews become flightless during molt
on the wintering grounds, when they are vulnerable
to introduced mammals such as feral dogs and cats.
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