Common Tern

Common terns occur across northern North America, Europe, northern Asia, northern Africa, and the Middle East, with migratory populations wintering much farther south. They use marine coasts as well as freshwater lakes and ponds. Adults have whitish-gray bodies, paler underparts, pointed wings, forked tails, black caps, and red bills, although their appearance changes seasonally. They average about 37 centimetres long and weigh approximately 120 grams. Males and females appear similar, with males averaging slightly larger (Animal Diversity Web).

Fish form the great majority of the common tern's diet. When prey is abundant, birds may catch more fish than they can immediately consume, leaving oversized or surplus fish around nesting colonies. Early in the breeding season they also take insects, annelids, and echinoderms. Courtship begins when males establish colony territories and offer fish to females. Additional displays involve posturing and mutual circling. These behaviors help form breeding pairs before eggs are laid on relatively open nesting ground (Animal Diversity Web).