Black
Tern
Unlike the familiar terns of the genus Sterna,
Black Terns rarely plunge-dive. Instead, they fly
with distinctive buoyant and erratic flight,
almost bat-like, often swooping low to pick up
some food item from the surface of shallow water.
Preferred breeding habitat of Black Terns
includes freshwater marshes, prairie sloughs, and
lake edges. The male performs a display flight
where he carries a small fish or dragonfly in
view of potential mates. A female that accepts
the invitation follows him to a perch where he
feeds her the prize. Black Terns are
semi-colonial nesters and only defend a small
territory a few feet around the nest. Nests may
be as close as 1 yard apart, but more typically
they are 15 to 60 feet apart, in clusters of 10
to 50 nests. Both parents make the nest. The nest
sites can be on top of muskrat houses, floating
root masses, driftwood, or boards. Sometimes
Black Terns may use an old coot or grebe nest.
They do not usually carry nest materials in
flight, but instead heave dead vegetation up from
the water and arrange it in a small cup at the
nest site. Both parents incubate the eggs.
Nesting success is variable; nests are so flimsy
and close to the water that they are often
destroyed by wind and wave action. Hatchlings are
semi-precocial and downy. They move about on the
nest for about two weeks, and start to fly at
three weeks.
During the breeding season, Black Terns pick
insects off of vegetation or capture them in the
air, including dragonflies, mayflies, beetles,
and moths. They also prey on small fish,
mollusks, crayfish, and spiders. Large numbers of
terns may hover over meadows and grassy marshes,
or follow plows to feed on exposed grubs.
After the young fledge, Black Terns gather at
favorable staging sites. Fall migration begins in
late July, with the juveniles typically leaving
about one month after adults. Singly or in small
groups, they pass to the Gulf Coast where they
may gather in flocks of thousands. While on the
coast and associating with other species of
terns, Black Terns feed on small fishes,
especially those driven to the surface by
underwater predators. Peak migration is in mid to
late August. The wintering range is from Panama
to Chile. Returning spring migrants reach Canada
in mid April to late May.
Black Terns occur locally throughout the northern
United States and central Canada. They occur only
sporadically and uncommonly throughout the
northeast and southern parts of the range and are
most abundant in the prairies of the Dakotas,
Alberta, Saskatchewan and Manitoba. Black Terns
also occur in Europe. The European population
winters in the Mediterranean and along the
African Atlantic coast.
Black
Tern Range Map
Description: The Black Tern is a
small, short-tailed, small-billed tern that is
easily identified in breeding plumage. At that
time it has a black head and body with dark gray
wings and tail, and white on the belly and under
the tail. In flight the tail is slightly forked,
appearing almost squared-off when spread. At rest
the wings extend well beyond the tail. The bill
is black, and the short legs are dark red.
Adults in winter and immatures have white
underparts. The head is white with dark gray
around the eyes, ear coverts, and nape. There is
a dark patch on the sides of the breast. The
wings and tail are uniform gray in all plumages.
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