Facts about the Caspian Tern it is a large tern, similar to a big-size gull that belongs to the Hydroprogne genus of the family Sternidae. The binomial name of this tern is Hydroprogne Caspia, and formerly it was a subspecies of the genus Sterna Caspia. Despite its wide range, the Caspian Tern is the only gull in its genus, and it has no subspecies acknowledged either. The Caspian Tern is also called in New Zealand the Tarauni, the Maori name.
As big as a large gull, the Caspian Tern is the biggest tern in the world. The Caspian Tern has a body length that ranges from 19 inches to 24 inches (48 cm to 60 cm), with wings, spanning from 50 inches to 57 inches (127 cm to 145 cm) and a body mass, ranging from 530 grams to 782 grams (18.7 Oz to 27.6 Oz).
An Adult Caspian Tern has black color legs, and an elongated, thick red-orange color bill with a petite black tip. The Caspian Terns have a white color head with a black color cap and white color belly, neck, and tail. The upper wings and the back of the Caspian Terns are pale gray in color, and their under wings are light with dark color feathers. During flight, the tail of the Caspian Tern is less forked than other varieties of terns and their wing tips attain the black color on their underside.
During the winter season, the black color cap of the Caspian Tern is still present, but with a few white lines on their forehead. The call of the Caspian Tern is a loud croak similar to a heron. The big coral red bill of the Caspian Tern makes it one of the most easily recognized terns all through its global range.
The breeding habitat of the Caspian Tern is in big lakes and sea coasts in North America, whereas their habitat in Europe is chiefly around the Black Sea and Baltic Sea. Other worldwide habitats of the Caspian Tern are in Africa, Asia, New Zealand, and Australia. Seabirds from North America will travel to southern coastlines, the northernmost parts of South America and the West Indies. Asian and European birds expend their non-breeding period in the Old World tropics. Caspian Terns also reside in Australia and Africa or they scatter over small distances in those countries.
The Caspian Tern feeds mostly on fish, for which they dive, floating high above the water and then sinking. Occasionally, Caspian Terns also feed on big insects, the juveniles, and eggs of other seabirds and rodents. Caspian Terns are capable of flying up to 60 kilometers (37 miles) from their breeding colony to grab the fish, and they habitually search for their food on freshwater ponds as well as at the ocean.
The breeding season of the Caspian Tern starts during spring and summer, and the female bird will lay one to three eggs in a single clutch. These eggs are light blue green in color, with deep brown marking. The Caspian Terns construct their nest either jointly in colonies, or individually in varied colonies of other gull and tern species. They build their nest on the ground in the middle of the sand and gravel, or occasionally on plants. Caspian Terns protect their eggs for 26 to 28 days. The juvenile Caspian Terns are variable in plumage design, from light creamy to a darker gray-brown and this difference helps adults in recognizing their individual chicks while returning to the settlement from feeding tours. Fledging in Caspian Tern juveniles takes place after 35 to 45 days.
The average lifespan of the Caspian Tern is 12 years.