294 
BIRDS OF NEW MEXICO 
Nest. —In colonies, chiefly in grassy marshes but also on tule rafts, and on islands 
on the sand or among stones; a scant lining or a rude nest. Eggs: 3, very variable, 
olive-gray, brownish, or rarely white or buff, heavily marked with chocolate. 
General Habits. —The Forster Tern should be watched for over 
large bodies of water in New Mexico during the migrations. When too 
far away to distinguish its black crown and forked tail, it may still 
be recognized as a tern by its graceful swallow-like flight and its habit 
of flying over the water with bill pointed down. When it has located 
its prey, it darts down, plunging into the water and, it is said, when 
necessary actually swims a few feet below the surface. Its notes are 
given by Doctor Chapman as a “ long-drawn, reedy cackle and a tweet- 
tweet-tweet-tweet” (Handbook). 
Additional Litekature. — Hersey, L. J., and R. B. Rockwell, Condor, XI, 
110, 111, 1909 (nest).— Rockwell, R. B., Condor, XIII, 57-61, 1911 (nesting). 
AMERICAN BLACK TERN: Chlidonias nigra surinamensis (Gmelin) 
Description. — Length: 9-10.2 inches, wing 8.2, bill 1.1, tail 3.7, forked for .9, 
bill 1.1. Adults in breeding plumage: Head, neck, and underparts black, except for 
white under tail coverts; back, wings, and tail dark gray ; iris dark brown, bill black 
From Biological Survey (L. A. Fuertes) 
Fig. 46. American Black Tern 
The black-headed adult in the foreground shows the white 
wing border better than the white-headed young in 
the left of the background 
suffused with deep red (Fuertes), legs and feet purplish. Adults in winter plumage: 
Foreparts and underparts white, head marked with dusky, black patch back of eye; 
upperparts bluish gray. Young in first muter plumage: Similar to winter adults but 
upperparts more or less washed with brownish, and sides and flanks tinged with 
gray. 
Range. —Breeds chiefly in interior of North America from central Alaska, Great 
Slave Lake, northern Manitoba, Hudson Bay, and eastern Ontario, south to inland 
lakes of New York, Ohio, Missouri, Kansas, Colorado, Utah, Nevada, and California; 
