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
Royal tern 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 too close to the high tide mark a spring tide would flood the nesting site and kill the chicks and make unhatched eggs infertile. The royal tern is one of the species addressed in the "Agreement on the Conservation of African-Eurasian Migratory Water Birds" (AEWA). The AEWA covers 255 species that depend on wetlands for part