Roseate tern and the bill black. Juvenile roseate terns have a scaly appearance like juvenile Sandwich Terns, but a fuller black cap than that species. This species breeds in colonies on coasts and islands, at times with other seabirds. In Australian territory, it has been recorded nesting alongside the black-naped tern ("S. sumatrana"), lesser crested tern ("Thalasseus bengalensis"), crested tern ("T. bergii"), fairy tern ("Sternula nereis"), bridled tern ("Onychoprion anaethetus") and silver gull ("Chroicocephalus novaehollandiae"). It nests in a ground scrape, often in a hollow or under dense vegetation, and lays one or two (rarely three) eggs. It is less defensive of
Tern another by call, and siblings also recognise each other's vocalisations from about the twelfth day after hatching, which helps to keep the brood together. Vocal differences reinforce species separation between closely related birds such as the least and little terns, and can help humans distinguish similar species, such as common and Arctic terns, since flight calls are unique to each species. Terns have a worldwide distribution, breeding on all continents including Antarctica. The northernmost and southernmost breeders are the Arctic tern and Antarctic tern respectively. Many terns breeding in temperate zones are long-distance migrants, and the Arctic tern probably sees