Newsletter / Blog
2012-04-06 How many breeding endemic bird species in the USA?
The USA has 13
breeding endemic bird species.
Black
Turnstone
The Black Turnstone - Arenaria melanocephala – is endemic to the west coast of North
America and breeds only in Alaska.
It winters on rocky shores along the Pacific coast of North America from
southern Alaska southwards as far as
north-west Mexico.
Description
Breeding-plumaged
adults have a black head and breast apart from a white spot between the eye and
bill, a white stripe over the eye and white flecks on the sides of the breast.
The upperparts are blackish-brown with pale fringes to the wing-coverts and scapular
feathers. The belly and vent are white. In flight it shows a white wingbar,
white shoulder patch and white tail with a broad black band across it. There is
white from the lower back to the uppertail-coverts apart from a dark bar across
the rump. The black bill is slightly upturned. The legs and feet are
blackish-brown with a reddish tinge.
Call
They have a
variety of calls, especially a rattling trill which can be heard throughout the
year. Other calls include a loud, screeching alarm call and a soft, purring
call uttered to young chicks. Displaying males produce a long series of
staccato notes in flight as well as chirruping trills on the ground.
Food
It feeds mainly
on invertebrates, particularly crustaceans and mollusks in winter and insects
during the breeding season. Seeds, eggs and carrion are also eaten. Limpets and
acorn barnacles are the most important food items on the wintering grounds of
the Black Turnstone. During the breeding season, they eat many insects as well
as some berries and seeds.
Breeding
The bulk of the
population nests in the Yukon-Kuskokwim Delta. It arrives on its breeding
ground from early May to early June with the males arriving first. The nest is
a scrape dug mainly by the male. It is usually located amongst sedges or
grasses. Four olive or pale green eggs with dark spots are laid. The eggs are
incubated for between 21 to 24 days by both parents. The young birds are able
to fly well after 25–34 days.
Conservation Status – Least concern
The U.S.
Shorebird Conservation Plan lists Black Turnstone as a "Species of High
Concern," based on relative abundance, threats on breeding grounds,
threats on non-breeding grounds, and most importantly, its very small breeding
distribution. The entire population of Black Turnstone, numbering approximately
80,000 birds, breeds in a narrow stretch of coastal plain in western Alaska. This
concentration of a limited population in a restricted geographic area places
the species at a higher risk of being seriously affected by a major catastrophe.
Birdwatching
Black Turnstones
are common throughout the winter on rocky shores along the outer coast of Washington and in Puget Sound south to Seattle.
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