A social bird, the elegant tern can often be seen foraging in flocks, although smaller foraging groups or solitary foraging may be more usual. When feeding in a flock, the elegant tern calls frequently with a distinctive ke-e-e-r. The diet consists mainly of fish, particularly northern anchovy (Engraulis mordax), as well as occasional crustaceans, with prey caught by hovering and then plunge-diving into shallow water (2) (3) (4) (6). The elegant tern is often the victim of piracy by other seabirds, which attack the tern to steal its prey (2) (3).
Breeding occurs between April and May (2) (3), the elegant tern nesting in dense colonies, often in the company of larger, more aggressive species such as Heermann’s gull (Larus heermanni) and Caspian terns (Sterna caspia), which may offer some protection against predators (3) (6). Nest-building and egg-laying are highly synchronised within the colony, occurring in most pairs within the same 24 hour period (2) (3). The elegant tern is thought to be monogamous, forming a pair bond through elaborate courtship displays. The nest consists of a shallow scrape on the ground, and a single egg is laid, which hatches after around 25 to 26 days (2) (3) (4) (6). Both the male and female help to incubate the egg and raise the chick. The young elegant tern leaves the nest after just a few days, joining other chicks in a ‘crèche’, where it is still fed by its parents (3) (4) (6). Although fledging may occur in 30 to 35 days (2), the young tern is dependent on the adults for up to six months, during which time it learns how to forage (3) (4). Breeding is thought to occur from around three years old (3).