Elegant Tern

The total population is around 90,000 pairs, with the majority on islets in the Gulf of California. It nests in a ground scrape and lays one or two eggs. Unlike some of the smaller Sterna terns, it is not very aggressive toward potential predators, relying on the sheer density of the nests (often only 20–30 cm apart) and nesting close to other more aggressive species, such as Heermann's gulls, to avoid predation. However, Heermann's gulls do predate some eggs and chicks, though more significant predators are the much larger and more predatory western and yellow-footed gulls. In May 2021, 1500 nests with thousands of eggs were abandoned when a drone crash landed near the nesting colony in Bolsa Chica Ecological Reserve, scaring off 2,500 nesting elegant terns and leading to a catastrophic loss.

The current genus name is derived from Greek Thalassa, "sea", and elegans is Latin for "elegant, fine". Though described in 1822, the genus was largely treated as a synonym of Sterna until a 2005 study demonstrated that the systematics of the terns needed review. The closest relative of the elegant tern is Cabot's tern T. acuflavidus, which breeds on the Atlantic coasts of the Americas; this species pair is then next most closely related to the Old World Sandwich tern.