Drake Northern Pintail

From the U.S. Fish and Wildlife Service, Mountain-Prairie Region:

This drake northern pintail has not yet molted in to its breeding plumage. It is likely a juvenile from a late hatch and is just beginning to show some of its breeding plumage, with a little of the reddish chocolate brown head and grey stripes under the wings. Over the coming weeks, its brown mottled juvenille plumage will be completely replaced by the breeding plumage of an adult drake. Photo: Tom Koerner / #USFWS