CHESTNUT-SIDED WARBLER 377 



no means restricted to tlie forest but is found wherever trees grow 

 fairly close together, as in coffee plantations with their planted shade 

 trees or along tree-bordered rivers flowing through the cultivated 

 lands. It habitually forages among the crowns of the trees, usually 

 well above the ground. Solitary in disposition, it does not form true 

 flocks; but because of its great abundance several are at times seen 

 in neighboring trees. By early March, the males, which at the time 

 of their arrival are hardly to be distinguished from the females, are 

 clad in their attractive nuptial dress. On April 5, 1937, among the 

 forests of southern Costa Rica, I found a male so attired who repeated 

 over and over a subdued version of his song — an unusual event, for 

 these warblers seldom sing while in Central America. 



"The chestnut-sided warbler has not been known to arrive in Cen- 

 tral America before the second half of September, a late date for 

 warblers. By tlie beginning of October, it becomes numerous ; before 

 the end of April, it has vanished. 



"Early dates of fall arrival in Central America are: Guatemala — 

 Chimoxan, September 27 (Griscom). Honduras — Tela, October 1, 

 1930. Costa Rica — San Jose, September 25 (Underwood), and Sep- 

 tember 28 (Cherrie) ; El Hogar, September 27 (Carriker) ; Basin of 

 El General, September 15, 1936, and October 3, 1942. 



"Late dates of spring departure from Central America are: Pan- 

 ama — Barro Colorado Island, Canal Zone, April 6, 1935. Costa 

 Rica— Basin of El General, April 15, 1936, April 21, 1937, April 25, 

 1939, April 20, 1940, April 12, 1942, and April 17, 1943 ; San Jose, 

 April 24 (Cherrie) ; Pejivalle, April 28, 1941. Guatemala — Motagua 

 Valley, near Los Amates, April 24, 1932." 



DISTRIBUTION 



Range. — Eastern North America to Panama. 



Breeding range. — The chestnut-sided warbler breeds north to cen- 

 tral Saskatchewan (Emma Lake and Hudson Bay Junction) ; south- 

 ern Manitoba (Duck Mountain, Lake St. Martin, and Hillside Beach) ; 

 central Ontario (Kenora, Chapleau, and Lake Abitibi) ; and southern 

 Quebec (Blue Sea Lake, Quebec, and Gaspe). East to southeastern 

 Quebec (Gaspe) ; Nova Scotia ( Antigonish, Halifax, and Yarmouth) ; 

 and the coast of New England south to Martha's Vineyard. South 

 to southern Massachusetts (Martha's Vineyard) ; southern Connecti- 

 cut (Saybrook, New Haven, and Bridgeport) ; northern New Jersey 

 (Elizabeth and Morristown) ; southeastern Pennsylvania (Berwyn) ; 

 northern Maryland (Reisterstown) ; south through the mountains of 

 Virginia, West Virginia, North Carolina, South Carolina (Caesars 

 Head and Highlow Gap) ; to central northern Georgia (Brasstown 



