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? according to their usual habitat. The accompanying text included brief notes on distribution, breeding and behaviour. While initial sales were poor, history tells us that Cayley had accurately discerned a market need and successfully responded to it. During WWII sales accelerated and Cayley’s first collection, reprinted time and time again, eventually became a household name among birdwatchers and the book was recognised as an Australian classic. The original sponsorship of "What Bird is That?" proved a great investment for the Gould League, who benefited from the sale of its numerous reprints and revised editions. By 1960, it was rated the