Lesser scaup in their first or second summer. The oldest known individual reached an age of over 18 years. Before the start of the population decline (see below), about 57% of the lesser scaup nests failed each breeding season because the female was killed or the eggs were eaten or destroyed. The average brood size of nests where eggs hatched successfully was 8.33 hatchlings. Although the lesser scaup has the largest population of any species of diving duck in North America, their population has been steadily declining since the mid-1980s, and reached an all-time low in the early 21sh century. During breeding
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