Redhead (Aythya americana) females carry nest parasitism to an extreme. Females parasitize each others nests and the nests of at least ten other duck species. They will also lay eggs in American bittern nests and in the nests of predatory northern harriers. In addition, redheads have nests where eggs are laid but never incubated. These “dump nests” have been known to hold as many as 87 eggs. Some redhead females are entirely parasitic and never incubate their own eggs.
Redhead nests are built in dense marsh above shallow water, occasionally on dry ground. The bulky nest is built up from dead vegetation, anchored to standing growth and lined with down. Most redheads nest in the prairie pothole region of North America but also summer in other areas, including central Alaska.
The male redhead has a rufous or cinnamon head, a yellow eye, heavily vermiculated back and smoky grey flanks. The female is brown all over with a slightly darker crown. Both sexes have distinctive black-tipped, grey bills.
The redhead diet is aquatic plants, mollusks and insects, rarely small fish. They forage by diving in water that is a few feet deep and dabble (upend) in very shallow water.
These redheads were photographed at different locations (Eagle Pole Loop and Quarry Trail) at Ash Creek Wildlife Area (Modoc and Lassen Counties CA).