Public opinion aroused by Audubon societies, and the Plumage Act ended that and saved them. Many people confuse terns with gulls but, although closely related, they have noticeable differences. Most terns are slim and stream-lined. Gulls are more heavily built, with broader wings and square or rounded tails. Both terns and gulls have webbed feet, swim easily, and gulls commonly alight on water to feed or rest.
Gulls are valuable as scavengers.
Terns prefer live food and seldom aligm on water but plunge headlong into it to capture prey beneath the surface. On the coast of Maine we saw a fishing vessel put out nets and fill her holds with tons of fish where thousands of terns were circling, shrieking and diving into a dense mass of herring driven to the surface by a hungry school of bluefish. There are about 50 species of terns and nearly all are seabirds but four of them are common in the interior of North America, either as migrants or as nesting birds. The Black Tern is most numerous. Its tail is shorter than those of most terns and notched instead of forked.