Least Tern: Sternula antillarum
Like all North American terns, the least tern has long, pointed
wings and a deeply forked tail. It is the smallest of our terns,
and bears outer wing feathers that edge the light-gray wings in
black. The breeding adult is gray above, white below, with a black
Not only are the birds extremely susceptible to nest
disturbance, they have lost extensive nesting habitat to beach
development and increased human activity there. Least terns are
colony nesters, meaning they nest in a group, which allows them to
exchange information about food sources, as well as to detect and
mob predators. An entire colony can be easily destroyed by
predation by red foxes, raccoons, dogs and house cats, by human
trampling, or by catastrophic storms.
In the past couple of decades, due to habitat loss, least terns
have taken to nesting on flat roofs, especially gravel ones. The
Florida Fish and Wildlife Conservation Commission has developed an
educational pilot program being implemented in Pinellas county. The
program is to help business (or home) owners educate their
customers about having tolerance for least terns that are
'squatting' on their flat, gravel roofs. A poster was developed to
promote the public educational project.
Least terns do respond quickly to improved habitat, such as the
removal of beach vegetation or the dumping of dredged sand. Least
tern populations seem to be slowly rising, although they are still
listed as 'threatened' by the state. At many nesting areas, signs
warn people against entering colonies, many of which are roped off
during breeding season.
In early spring least terns return from wintering grounds in
Latin America. They soon pair up using courtship rituals in which
hopeful males offer small fish to prospective mates. The shorebirds
nest in very shallow depressions on broad expanses of bare sand,
which camouflage the eggs. They lay from mid-April in south Florida
to the first of May in the north, and the eggs hatch after 21 days.
The young leave the nest in a few days, but don't begin to fly
safely until about three weeks later.