Caspian Terns are the only large terns likely to be seen on
inland waters, including within South Dakota. Less sociable than many
terns, they are often seen singly or in small groups. Known for their
aggressive feeding tactics, Caspian Terns won't hesitate to steal a catch from
another bird, or raid a nesting colony for eggs and young birds. Young of
the species are dependent upon their parents for a much longer period of time
than most other terns and gulls, and can still be seen begging parents for food
Habitat: Prefers large expanses of water,
including coastlines, large lakes, reservoirs, and large rivers.
Diet: Primarily feeds on fish. They often focus on just
one or two primary prey species, which vary from location to location.
They will also feed on large insects, eggs and young birds, and occasionally
crustaceans or mollusks.
Behavior: Feeds by plunging into the water for
prey after spotting it in flight. Very aggressive, they will often
steal food from other bird species.
Nesting: June and July. The nest of a Caspian
Tern is a shallow depression on the ground, sometimes lined with bits of
vegetation or debris. The female usually lays between 1 and 3 eggs, and
both parents help to incubate them. When the eggs hatch, both parents help
to feed the y oung. Young fledge after about a month, but typically stay
with the parents for several months after fledging.
Breeding Map: Only
a very rare breeder in South Dakota. Breeding Bird Survey map unavailable.
Migration: Summers along coastlines and in widely scattered inland locations throughout
Canada and the United States. Inland birds move to coastlines in the
winter, and wintering birds can be found southward through northern South
Similar Species: In South Dakota, somewhat similar to
Common Tern and Forster's Tern,
but large size and heavy bill make it quite distinctive. Ini other parts
of its range, most likely to be confused with
Cornell University's "All About Birds - Caspian Tern"
eNature.com: Caspian Tern
Photo Information: February 13th, 2008 - Bon
Secour National Wildlife Refuge, Alabama - Terry Sohl
Additional Photos: Click on the image chips or
text links below for additional, higher-resolution Caspian Tern photos.