Fairly common migrant, more so in autumn than in spring, near fresh and salt water. Spring adults have the whole head and underparts black; in the autumn plumage the forehead, nape, and underparts are white. Immature birds are like autumn adults but have the back tinged with brownish. Sexes are alike.
The specimen on the left is in winter, non-breeding plumage.
Collected By: Mr Hamilton
Locality: Washington, DC (Carp Ponds) (Constitution Gardens)
Sex: Male, Juvenile
Catalog ID: 75363
The specimen on the right is in breeding plumage.
Collected By: NR Wood, WH Hoyt
Locality: Ottawa Co, KS
Catalog ID: 257590