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
Gull Island (Tasmania) sooty oystercatcher and crested tern. Gull Island (Tasmania) The Gull Island, part of the Passage Group within the Furneaux Group, is an granite island, located in Bass Strait southeast of Cape Barren Island, in Tasmania, in south-eastern Australia. The island is a conservation reserve and with the Passage and Forsyth islands, the Gull Island forms part of the Forsyth, Passage and Gull Islands Important Bird Area (IBA), identified as such by BirdLife International because it supports over 1% of the world populations of little penguins and black-faced cormorants. Recorded breeding seabird and wader species include little penguin, short-tailed shearwater, white-faced