Ivory gull narrower os pubis, and potentially more flexibility in skull kinetic structure. Structurally, it is most similar to the kittiwakes; however, recent genetic analysis based on mtDNA sequences shows that Sabine's gull is the ivory gull's closest relative, followed by the kittiwakes, with Ross's gull and swallow-tailed gull sharing a clade with these species. "Pagophila" is maintained as a unique genus because of the bird’s morphological, behavioral and ecological differences from these species. Colloquial names from Newfoundland include slob gull (from "slob", a local name for drift ice) and ice partridge, from a vague resemblance to a ptarmigan. This species is
Common square-tailed drongo to three eggs are laid in a cup nest in a fork high in a tree. These are aggressive and fearless birds, given their small size, at 19 cm, and will attack much larger species if their nest or young are threatened. The male is mainly glossy black, although the wings are duller. The female is similar but less glossy. The bill is black and heavy, and the eye is red. This species is similar to the fork-tailed drongo, but is smaller, and the shorter tail lacks the deep fork which gives the latter species its name. Fork-tailed is also