Gull the exceptions being Sabine's gull and swallow-tailed gulls, which have forked tails, and Ross's gull, which has a wedge-shaped tail. Gulls have moderately long legs, especially when compared to the similar terns, with fully webbed feet. The bill is generally heavy and slightly hooked, with the larger species having stouter bills than the smaller species. The bill colour is often yellow with a red spot for the larger white-headed species and red, dark red or black in the smaller species. The gulls are generalist feeders. Indeed, they are the least specialised of all the seabirds, and their morphology allows for
Gull species and only one egg for the swallow-tailed gull. Within colonies, birds synchronise their laying, with synchronisation being higher in larger colonies, although after a certain point, this levels off. The eggs of gulls are usually dark tan to brown or dark olive with dark splotches and scrawl markings, and are well camouflaged. Both sexes incubate the eggs, with incubation bouts lasting between one and four hours during the day and one parent incubating through the night. Research on various bird species including the gull suggests that females form pair bonds with other females to obtain alloparental care for their