A male and female ruddy ground dove (Columbina talpacoti talpacoti) at the Membeca Lagos Farm, near Rio de Janeiro, Brazil.
A pair of black-headed ducks (Heteronetta atricapilla) at Sylvan Heights Bird Park in Scotland Neck, North Carolina.
The male is darker, while the female is brown.
A pair of Steller’s eiders (Polysticta stelleri) at the Alaska SeaLife Center in Seward.
The male is white and black, the female is brown.
This species is listed as vulnerable on the IUCN Red List.