Caspian Tern

The Caspian Tern is the largest tern in Australia, with 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 nape and a short shaggy black crest. The mantle and upperwings 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. The sexes are similar. Immature birds are similar to non-breeding adults. Younger birds are mottled grey and brown.

Caspian Terns are found throughout Australasia, North America, Eurasia and Africa.

Caspian Terns are usually found near the coast, in extensive wetlands, on coastal and interior beaches and sheltered estuaries. The Caspian Tern lives equally well in fresh water and saline environments.

Caspian Terns are common and widespread (though seldom in large numbers). They are mainly sedentary (stay in one area) but numbers fluctuate seasonally in many areas. Records of banded birds show that the young disperse widely. From Tasmania they go north in winter to New South Wales waters. From a large breeding colony at Lake Moondarra, near Mt. Isa, Queensland, banded birds have moved east and south as far as Murray Bridge, South Australia - a direct flight of about 1500 km.

Caspian Terns feed almost entirely on fish. They usually feed by shallow plunging; hovering up to 15 m above the water with bill pointing down, before folding wings in and diving, fully submerged, to 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.

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.