- Sterna caspia
Identification
The Caspian Tern is the largest tern, growing to 23 inches, with a wingspan up to 4.5 feet. In New Zealand it is also known by the Maori name Taranui.
Adult birds have black legs and a long thick red-orange bill. They have a white head with a black cap and white neck, belly and tail. The upper wings and back are pale grey; the underwings are pale with dark tips. In flight, the tail is less forked than other terns and wing tips black on the underside.
The call is a loud heron-like croak.
Distribution
North American birds migrate to southern coasts, the West Indies and northern South America. Eurasian birds winter in the Old World tropics. Their breeding habitat is large lakes and ocean coasts in North America including the Great Lakes and locally across much of Europe, Asia, Africa, Australia and New Zealand.
The Caspian Tern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.
Taxonomy
Sometimes considered part of genus Hydroprogne (see Bridge et al, 2005).
Habitat
Their breeding habitat is large lakes and ocean coasts.
Behaviour
These birds dive for fish, hovering high over the water and then plunging. They also sometimes eat insects and the young and eggs of other birds.
Breeding is in spring and summer, with 1-3 pale blue green eggs heavily spotted brown laid. They usually nest on the ground among debris or sometimes on floating material.
Vocalisation
<flashmp3>Sterna caspia (song).mp3</flashmp3>
Listen in an external program
