Wikipedia:Today's featured article/August 14, 2015

Terns are seabirds in the family Sternidae that are found worldwide, generally near the sea, rivers or wetlands. They are slender, lightly built birds with long forked tails, narrow wings, long bills and relatively short legs. Most species are pale grey above and white below, with a contrasting black cap, but the marsh terns, the Inca tern and some noddies have dark plumage for at least part of the year. The sexes are identical in appearance. They are birds of open habitats that typically breed in noisy colonies and lay their eggs on bare ground with little or no nest material. Many terns are long-distance migrants, and the Arctic tern, migrating each year between the Arctic and Antarctic, may see more daylight in a year than any other animal. They are long-lived birds and are relatively free from natural predators and parasites, but most species are declining in numbers through habitat loss, polluted waters, human encroachment and predation by introduced mammals. Three tern species are classed as endangered, and the Chinese crested tern is critically endangered. International agreements provide a measure of protection, but adults and eggs of some species are still used for food in the tropics.