Greater scaup faces numerous threats, the most significant challenge to their survival is habitat degradation caused by a mix of human development and runoff. Greater scaup, when moulting and during the winter, are threatened by escalated levels of organochloride contaminants. Oil and sewage pollution also threaten this duck. Since 80% of the greater scaup population winters in the urbanized part of the Atlantic Flyway, these ducks are subject to high levels of organic contaminates, along with increased levels of heavy metals in foods and habitat. A joint group of American and Canadian scientists researching scaup migration across the Great Lakes found that
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