Sabine's gull treated as comprising a monotypic genus; it is only placed within the genus "Larus" when the genus is enlarged. The black bill and notched tail are almost unique within the gulls, as they are shared only with the swallow-tailed gull of the Galapagos. On the basis of this the two species were often thought to be each other's closest relatives, a hypothesis ruled out by a number of behaviour and ecological differences. Mitochondrial DNA studies confirmed that they are not closely related, and the closest relative of the Sabine's gull is now thought to be the ivory gull, another Arctic
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