USGS Home
Contact USGS
Search USGS

COMMON TERN Sterna hirundo L14" (37cm)

Anglers on Lake Sakakawea are probably familiar with the common tern for it is often seen hovering over fishing boats waiting for dead, discarded minnows. It inhabits large freshwater lakes and rivers in North Dakota such as Devils Lake, Lake Sakakawea, Lake Metigoshe, and the Missouri River System. During the breeding season, it nests on flat sandy beaches, sandbars, and sparsely vegetated islands. The nest of the common tern consists of a small depression in the sand and is often lined with aquatic weeds and grass. The female lays 2-4 sand colored eggs with an incubation period lasting 23-27 days. Both adults defend the eggs and chicks with great tenacity, often diving at and defecating on intruders. When feeding, the common tern will hover over a school of fish and then suddenly plunge into the water to nab its prey. Small fish make up the majority of the common tern's diet but it will also feed on crustaceans and insects.