Greater Scaup Aythya marila

Scaup, 1W drake, Warks, November 2019.

© A. R. Dean

The progress of moult from 1W to adult-like plumage in the above individual was relatively rapid. By early January, apart from tell-tale signs, it appeared close to an adult drake. In 'Wildfowl of Europe, Asia and North America', Reeber (2015) wrote of first-winter male: 'Acquisition of formative plumage is protracted over several months but is quite variable in extent and speed of development, so it is normal to see first winter males at different stages side by side... In early spring those birds whose moult was less extensive still look variegated but others are close to adult...'.  BWP1 (Cramp & Simmons 1977) wrote of first-winter drake: 'New feathers, resembling adult breeding from October. At times, in breeding plumage (except wing) before winter but usually combination of juvenile, first non-breeding and first-breeding plumage during winter.' The following composite shows the development of the Warks individual between late November and early January.

Moult-progress in 1W drake Scaup, Warks, Nov. 2019 - Jan. 2020.

© A. R. Dean