Tern make up the clutch. Most species feed on fish caught by diving from flight, but the marsh terns are insect-eaters, and some large terns will supplement their diet with small land vertebrates. Many terns are long-distance migrants, and the Arctic tern may see more daylight in a year than any other animal. Terns are long-lived birds and are relatively free from natural predators and parasites; most species are declining in numbers due directly or indirectly to human activities, including habitat loss, pollution, disturbance, and predation by introduced mammals. The Chinese crested tern is in a critical situation and three other
Antarctic tern Antarctic tern The Antarctic tern ("Sterna vittata") is a typical tern. It ranges throughout the southern oceans. It is very similar in appearance to the closely related Arctic tern, but is stockier, and the wing tips are grey instead of blackish in flight. It is in breeding plumage in the southern summer, when the Arctic tern has moulted to its non-breeding plumage (though this is not useful for separating it from another species, the South American tern). Breeding takes place from mid-November to early December. Chicks hatch from December to February. Skuas and jaegers are the primary predators of the