The Caspian Tern is found in coastal areas around Bundaberg as well as on inland freshwater lakes such as Lake Monduran. Picture: Contributed
The Caspian Tern is found in coastal areas around Bundaberg as well as on inland freshwater lakes such as Lake Monduran. Picture: Contributed

BIRDWATCH: Caspian tern’s spectacular plunge to catch fish

The Caspian Tern is the largest tern in the world and is found in North America, Europe, Asia, Africa, New Zealand and Australia.

It has long, slender backswept wings and a slightly forked tail. The heavy bill is red with a dusky tip.

When breeding the tern is white, except for a black crown from bill to neck and a short shaggy black crest.

The back and upper wings are grey and the flight feathers are darker.

The eye is dark brown and legs are black.

When not breeding, the crown is finely streaked white.

They feed almost entirely on fish which they catch by plunging head first into the water.

The technique is to hover up to 15m above the water with bill pointing down, when they see a fish they fold the wings in and dive under the water to catch the fish and quickly re-emerge. They usually swallow fish in flight, head first.

Most feeding activity is in the early to mid-morning.

Whole fish are regurgitated to feed the young.

The courtship behaviour involves the male flying low over a breeding colony carrying a fish followed by a female.

Upon landing he will present the fish to the female and her acceptance establishes a bond between the two.

Caspian Terns breed in scattered single pairs or dense colonies.

Both sexes share nest-building, incubation and care of the young.

The nest is a deep scrape, usually unlined, but occasionally sparsely ringed with debris or scraps of local vegetation such as saltbush.

The Caspian Tern is found in coastal areas around Bundaberg as well as on inland freshwater lakes such as Lake Monduran.

Allan Briggs is the secretary of BirdLife Capricornia, contact him with your bird questions at abriggs@irock.com.au