Royal Tern

Description:

This is a large tern, second only to Caspian Tern but is unlikely to be confused with the carrot-billed giant, which has extensive dark under wing patches. The Royal Tern has an orange-red bill, pale grey upper parts and white under parts. Its legs are black. In winter, the black cap becomes patchy.[4] Juvenile Royal Terns are similar to non-breeding adults. Differences include juveniles having black splotched wings and a yellower bill. An adult Royal Tern has an average wingspan of 130 centimetres (51 in), for both sexes, but their wingspan can range from 125–135 cm (49–53 in). The Royal Tern's length ranges from 45–50 cm. (18–20 in) and their average weight is anywhere from 350-450 grams (12-16 oz).[5] The calls of the Royal Tern are usually short, clear shrills. Some of the shrills sound like kree or tsirr; the Royal Tern also has a more plover like whistle that is longer, rolling and is more melodious.[6] In various parts of its range, the Royal Tern could be confused with Elegant Tern, Lesser Crested Tern (the other orange-billed terns), and the Great Crested Tern. It is paler above than Lesser Crested Tern and the yellow-billed Great Crested Tern. Elegant Tern has a longer more curved bill and shows more white on the forehead in winter.

Habitat:

In the Americas the Royal Terns on the east coast, during the breeding season(April–July), occur in the US north to Virginia, occasionally drifting north to Maryland. The southern end of their breeding range is Texas. The wintering range for on the east coast is from North Carolina south to Panama and the Guianas, also the Caribbean islands. On the western coast of the Americas the Royal Tern spends the breeding season from the US state of California to Mexico, wintering from California south to Peru.[7] In Africa the Royal Tern is found along the west coast in the islands off the coast of Mauritania during the breeding season, but it is believed that there are undiscovered colonies on the west coast near or in Nigeria. The Royal Tern usually winters from Morocco and south to Namibia. The Royal Tern is not usually found in Europe although it has been seen in the western European countries of Spain and Gibraltar. Also, it has been seen farther north in Europe, but those cases are not confermed.[7] American birds migrate south to Peru and Argentina for the winter to escape the cold weather. African breeders move both north and south from the breeding colonies.[8] African birds may reach as far north as Spain. This species has also wandered to Western Europe as a rare vagrant, these terns are probably from the American colonies.[7

Notes:

The Royal Tern has few predators when it is mature, but before the chicks hatch or while they are chicks the tern is threatened by humans, other animals, and the tides.[13] Humans threaten terns by fishing and by disrupting the tern nesting sites. Fishing nets can catch a tern while it is diving, making it unable to feed or it may cause it to drown if it is caught under water. Animals such as foxes, raccoon, and large gulls prey on tern chicks and tern eggs. Tern nesting sites can also be affected by the tides; if a tern colony has nested to close to the high tide mark a spring tide would flood the nesting site and kill the chicks and make unhatched eggs infertile