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 tern subspecies are endangered, including the California least tern and the Easter Island race of the grey noddy. Most tern species are declining in numbers due to the loss or disturbance of breeding habitat, pollution and increased predation. Gull populations have increased over the last century because of reduced persecution and the availability of food from human activities, and terns have been forced out of many traditional nesting areas by the larger birds. A few species are defying the trend and showing local increases, including the Arctic tern in Scandinavia, Forster's tern around the Great Lakes, the Sandwich tern in