AUGUSTA, Maine (AP) — Wildlife officials are surveying gull and cormorant populations on Maine's coastal islands.

The Department of Inland Fisheries and Wildlife in collaboration with the U.S. Fish and Wildlife Service is monitoring population and breeding distribution changes of great black-backed gulls, herring gulls and double-crested cormorants. They're also surveying common eiders on selected islands.

The survey is using a combination of aerial photographs, aerial counting and ground surveys in which crews walk the islands and count the number of nests that contain eggs.

Officials say between 1996 and 2008, the number of nesting black-backed gulls declined 42 percent, nesting herring gulls fell 30 percent and nesting cormorants dropped 45 percent. Biologists believe the decline is due to fewer fish to feed on and increased predation from a growing eagle population.