176 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



larly, great numbers are in evidence. The first arrivals reached Lake 

 Olomega on August 1, but the main body did not begin to drift 

 through until about the middle of that month." 



Frederick C. Lincoln (1939) remarks: "Kedstarts and Yellow 

 Warblers, doubtless the more southern breeders in each case, have been 

 seen returning southward on the northern coast of South America just 

 about the time that the earliest of those breeding in the North have 

 reached Florida on their way to winter quarters." 



Winter. — Dr. Alexander F. Skutch contributes the following winter 

 notes: "This morning as I sat at breakfast a yellow warbler flitted 

 among the shrubbery outside the window. Here in Central America, 

 through 8 or 9 months out of the 12, this well-known bird occupies the 

 same place in dooryard, garden, hedgerow and scrubby pasture 

 as during its briefer sojourn in the more northerly regions where it 

 nests. None of the resident warblers of Central America is quite 

 so abundant and familiar about human dwellings. Everywhere it 

 avoids the heavy forest and prefers the sunlight that floods the clear- 

 ings made by man. 



"It is one of the first of the visitants from the North to arrive in 

 Central America, appearing in Guatemala as early as August 9, 

 reaching Honduras by at least the fourteenth, Costa Rica by 

 the seventeenth, and Panama by the twenty-second of the month. 

 These early dates are for the Caribbean lowlands, along which it ap- 

 pears to migrate. It arrives later on the Pacific side of the Isthmus, 

 especially in Costa Rica, where it has not been recorded before August 

 24, at San Jose, and not until September 11 in the Terraba Valley, 

 still more isolated from the Caribbean fly way by lofty, forested moun- 

 tains. But by the end of September, it is well distributed as a 

 winter resident over both coasts of Central America, and in the 

 interior up to at least 5,000 feet, becoming rarer at the upper lunit 

 of its altitudinal range. Much above 5,000 feet it apparently does 

 not winter; but it is occasionally seen in September in the high 

 mountains as a bird of passage. A heat-loving warbler, it is most 

 common in the lowlands where, in the plantation districts of northern 

 Central America during the winter months, it is among the most 

 abundant birds, whether resident or migratory. 



"Although a number of wood warblers which winter in the Central 

 American highlands are gregarious, those that center in the lowlands 

 are tyj)ically solitary. In this, the yellow warbler is no exception. 

 Each wintering bird appears to have its own territory, from which 

 it attempts to drive others of its kind. Trespassers are scolded with 

 insistent chips/ or more rarely, soon after his arrival, a male will 

 sing while defending his claim. Near San Miguel de Desamparados, 

 Costa Rica (4,600 feet), on October 1, 1935, I made the following 



