Marin County
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Forster's Tern
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Gull-like Birds |
Forster's Tern Sterna forsteri
Description ADULT SUMMER Has mainly pale gray back and upper wings, black cap, and otherwise white plumage. Legs are orange-red and bill is orange-red with black tip. In flight, note dark trailing edge to otherwise white primaries (lack dark "wedge" on Common's inner upper primaries). ADULT WINTER Looks pale overall, except for dark "mask" through eye, black bill, and darker primaries (especially margins). JUVENILE Similar to winter adult, but with buff feathers on back, upper wing, and crown, pale-based bill, and shorter outer tail feathers; first-winter is similar to winter adult but with shorter outer tail feathers.
Dimensions Length: 14-15 in (36-38 cm)
Habitat Nests beside freshwater marshes; other times commonest near coasts.
Observation Tips Easy to see at freshwater sites in summer and coasts in winter.
Range Southwest, Eastern Canada, Western Canada, California, Northwest, Rocky Mountains, Plains, New England, Great Lakes, Florida, Mid-Atlantic, Texas, Southeast
Voice A harsh kree-err call.
Discussion Paler than Common with longer, more deeply forked tail, longer legs, and different upper wing pattern. Much less pelagic than Arctic and, of the three, the only one likely to be seen here in winter. Sexes are similar.
