Larus

Larus is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls were placed in this genus, but this arrangement is now known to be polyphyletic, leading to the resurrection of the genera Chroicocephalus, Ichthyaetus, Hydrocoloeus, and Leucophaeus for many other species formerly included in Larus. They are in general medium-large birds, typically pale grey to black above and white below and on the head, often with black markings with white spots ("mirrors") on their wingtips and in a few species also some black on the tail. They have stout, longish bills and webbed feet; in winter, the head is often streaked or smudged dark grey. The young birds are brown, and take three to five years to reach adult plumage, with subadult plumages intermediate between the young and adult. The taxonomy of the large gulls in the herring and lesser black-backed complex is complicated, with different authorities recognising from two species in the past, increasingly up to eight species more recently.