298 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



Fall. — By the middle or last of August, when the young birds have 

 acquired their first winter plumage and most of the adults have com- 

 pleted their molt, the fall migration begins in a leisurely way, as 

 the birds are in no hurry to reach their winter homes. Their wander- 

 ings are more extended at this season and more erratic. Generally a 

 few, and sometimes large numbers, of black terns, mostly in immature 

 plumage, are seen on the Atlantic coast from New England south- 

 ward, sometimes in large flocks by themselves frequenting the marshes 

 and wet meadows, but more often in small numbers mingled with 

 other terns and gulls along the coast. Rev. M. B. Townsend writes 

 to me that he has seen black terns flying over the waters of the (^ulf 

 of Mexico as early as August 1, some of which were still in full 

 spring plumage, some were molting, and some had completed the 

 molt into winter plumage. On June 16, 1910, while cruising oif the 

 coast of Louisiana, I saw^ a large number of black terns in small 

 flocks ; I counted 10 of them sitting on a stick of drift timber, equally 

 spaced about a foot apart. They evidently thought that there was 

 no more standing room, for they would not alloAV another bird to 

 alight on the log, although several tried to do so. Capt. W. M, 

 Sprinkle told me that they breed in the West Indies in February, 

 appear here early in May, and remain all summer. I am more in- 

 clined to think that these were nonbreeding birds which failed to 

 migrate northward in the spring. 



DISTRIBUTION. 



Breeding range. — Interior of North America. East to eastern On- 

 tario (Kingston and Charleston Lake) and west central New York 

 (Cayuga Lake). South to northern Ohio (Sandusky), northern In- 

 diana (English Lake), northern Illinois (Cook, Putnam, and Henry 

 Counties), central Iowa (Hamilton Count}^), northern Nebraska 

 (Holt and Cherry Counties), north central Colorado (Barr Lake 

 region), north central Utah (Utah Lake), western Nevada (Washoe 

 Lake), and southern California (Elsinore Lake). West to central 

 California (San Joaquin and Sacramento Valleys), central southern 

 Oregon (Klamath Lakes), east central Washington (Brook Lake), 

 and central British Columbia (Chilcotin). North in the interior to 

 central Alaska (Fort Yukon), Great Slave Lake, and central Mani- 

 toba (Lake Winnipegosis and Lake Winnipeg). 



Breeding grounds protected in the following national reservations : 

 In Oregon, Klamath Lake, and Malheur Lake. 



Winter range. — From the Gulf of Mexico southward to northern 

 South America (Surinam), and along the Pacific coasts of Mexico 

 (Mazatlan), Panama, Peru, and Chile. Nonbreeding and young 

 birds remain in the Gulf of Mexico all summer. 



