TERNS ARE LIKE dainty, small, graceful versions of gulls. They are mainly summer birds in the UK, coming here to breed, on selected beaches or inland sites in the case of Common Tern. Some species, notably the Black Tern, are passage birds, just passing through on the way to or from the continental breeding grounds. All are lovely birds, but can be tough to identify, especially for the inexperienced. Most terns are largely seabirds, with a diet mainly comprising small fish. However, the three species of marsh tern (Black, White-winged Black and Whiskered), also eat a lot of emerging insects, as will other terns when the conditions are right. Here are six tern species to identify. Name them, then turn (ahem) the page for our ID analysis and further ID advice for terns and more.