- Larus atricilla
Identification
L. 36-41 cm
W. 98-110 cm
One of two North American dark-backed hooded gulls.
Field marks include dark almost slate colored back, small white primary tips, large bill, narrow eye-arcs, and extensive hood (in breeding plumage). Nonbreeding has limited remnants of hood and black bill. Juveniles have totally black primary tips, gray neck, and black bill.
Similar species
Bonaparte's Gull is smaller with much lighter gray back, smaller black bill (in all plumages), and with almost no white on primary tips.
Black-headed Gull is slightly larger with much lighter gray back, less extensive hood, and with mostly no white to primary tips.
Franklin's Gull is a slightly smaller dark-backed hooded gull with larger white primary tips (even in juvenal plumage), much less extensive black in wingtips when flying, broader eye-arcs, and smaller thinner bill. Juvenile Franklin's have whitish neck (instead of gray).
Distribution
Year-round resident on eastern and southern coastline of the U.S. from Maine to the southern tip of Texas. Winters in Mexico. Rare away from east coast and south coast of the U.S. but with records in almost every state.
Vagrant to Europe with several records annually in the UK.
Taxonomy
Polytypic. Consists of two subspecies.
Habitat
Coastal islands, saltmarshes and sand-dunes.
Behaviour
Often gathers in large flocks in beachfront areas on lawns, park areas, parking lots, etc.
Diet
Omnivorous - diet includes fish, insects, carrion, mollusks, eggs, worms, young birds, etc. Collects food by foraging on beaches and shallows; does not submerge in search of food like some other shorebirds.
They are scavengers as well as hunting small prey.
Breeding
A large nest is built of grass and placed on the ground. 3-4 greenish eggs are laid and incubated for about 21 days.