Marabou stork was moved into the genus "Leptoptilos" and the ending was modified to "crumeniferus" and used by many authors until it was noted that the correct masculine ending to match the genus is "crumenifer". The marabou stork is a massive bird: large specimens are thought to reach a height of and a weight of . A wingspan of was accepted by Fisher and Peterson, who ranked the species as having the largest wing-spread of any living bird. Even higher measurements of up to have been reported, although no measurement over has been verified. It is often credited with the largest spread
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