This Week’s Creature Feature: One Big Ornery Bird
The great black-backed gull, the largest of its kind in the world, lives and nests along Chesapeake Bay. With a five-and-a-half-foot wingspan, these birds are much larger than the more common ring-billed gull or herring gull. These strong flyers are also very aggressive toward other birds.
As well as size, the great black-backs have distinctive markings. Wings are black on top and gray underneath. Chest, neck and head are white and the bill large and yellow. Legs are pale and pinkish.
A lesser black-backed gull from Europe occasionally appears along our shoreline. They are smaller with yellow legs.
The greater black-backed gull usually hunts along the shoreline, seeking crabs, urchins and fish. But they also prey upon eggs and the young of other birds. They are known to steal from other birds and to stalk small ducks coming up from a dive. They have few enemies, save for egg-stealing nocturnal mammals. I have seen them chased by the smaller peregrine falcon and similar-sized osprey. Both, I think, were protecting a nest or territory.
Black-backed gulls nest together in rocks and the dunes near a shore, using grasses and shore debris to line their nest. The two or three young that hatch grow fairly quickly and leave the nest in two to three weeks. Before they leave the nesting area, the young have to avoid approaching other nesting gulls, as unrecognized nestlings are attacked and frequently killed.