A male and female mandarin duck (Aix galericulata) at Martin Mere, Lancashire, United Kingdom, showing the sexual dimorphism of the species. The adult male has a red bill, large white crescent above the eye and reddish face and "whiskers", as well as a purple breast with two vertical white bars, and ruddy flanks. The female is similar to female wood duck, with a white eye-ring and stripe running back from the eye, but is paler below, has a small white flank stripe, and a pale tip to its bill.
This species was once widespread in East Asia, but large-scale exports and the destruction of its forest habitat have reduced populations. A large feral population has been established in Great Britain.Photograph: Francis C. Franklin