Greater scaup been described by Serebrovskij in 1941 from fossils recovered at Binagady, Azerbaijan. The greater scaup's name may come from "scalp", a Scottish and Northern English word for a shellfish bed, or from the duck's mating call: "scaup scaup". A phylogenetic analysis of the diving ducks, examining the skeletal anatomy and skin, found that the greater and lesser scaups are each other's closest relatives, with the tufted duck as the next closest relative of the pair. The adult greater scaup is long with a wingspan and a body mass of . It has a blue bill and yellow eyes and is
What Bird is That? kookaburra seated on and within a large red question mark. It contains 36 coloured plates of paintings of Australian birds by the author, as well as several black-and-white photographic plates of habitat. There were numerous reprints and revised editions in various formats produced well into the 1980s. The first edition was sponsored by the Gould League of Bird Lovers of New South Wales of which Cayley was a Council member. In return for its sponsorship, Cayley offered the Gould League four tenths of his 10% book royalty. However, initial sales were slow and in 1935 he sold his entire share