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
Four Letter Word (Kim Wilde song) of her early hits together, including the pop classic "Kids in America)". It became her third consecutive UK Top 10 single from "Close", reaching number 6. An extended version as well as an acoustic remix of "Four Letter Word" were released as a 12" and CD-single. Four Letter Word (Kim Wilde song) "Four Letter Word" is the fourth single from the Kim Wilde album "Close". It was released at the end of 1988 — the year that had seen Wilde release a best-selling album, have four international hits (including the chart-topping "You Came") and support Michael Jackson on the European