BLACK-AND-WHITE WARBLER 13 



"Wintering throughout the length of Central America, from near 

 sea level up to 9,000 feet and rarely higher, the black-and-white 

 warbler is somewhat more abundant in that portion of its altitudinal 

 range comprised between 2,000 or 3,000 and 7,000 or 8,000 feet above 

 sea level. It is found in the heavy forest, in the more open types 

 of woodland, among the shade trees of the coflfee plantations, and even 

 amid low second-growth with scattered trees. It creeps along the 

 branches in exactly the same fashion in its winter as in its summer 

 home. Solitary in its disposition, two of the kind are almost never 

 seen together. The only time I have heard this warbler sing in Central 

 America was also one of the very few occasions when I found two 

 together. Early on the bright morning of September 1, 1933, when the 

 warblers were arriving from the north, I heard the black-and-white's 

 weak little song repeated several times among the trees at the edge 

 of an oak wood, at an altitude of 8,500 feet in the Guatemalan high- 

 lands. Looking into the tree tops, I saw two of these birds together. 

 Apparently they were singing in rivalry, as red-faced warblers, Kaup's 

 redstarts, yellow warblers, and other members of the family solitary 

 during the winter months will sing in the face of another of their 

 kind, at seasons when they are usually silent. Often such songs lead 

 to a pursuit or even a fight; but I have never seen black-and-white 

 warblers actually engaged in a conflict in their winter home. 



"Although intolerant of their own kind, the black-and-white war- 

 blers are not entirely hermits ; for often a single one will attach itself 

 to a mixed flock of small birds. In the Guatemalan highlands, during 

 the winter months, such flocks are composed chiefly of Townsend's 

 warblers ; and each flock, in addition to numbers of the truly gregari- 

 ous birds, will contain single representatives of various species of 

 more solitary disposition, among them often a lone black-and-white, 

 so different in appearance and habits from any of its associates. 



"This warbler arrives and departs early. It has been recorded 

 during the first week of August in Guatemala, and by the latter part 

 of the month in Costa Rica and Panama. In Costa Rica, it appears 

 not to linger beyond the middle or more rarely the end of March; 

 while for northern Central America my latest date is April 22. 



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

 passim (Griscom), August 3; Sierre de Tecpan, August 23, 1933; 

 Santa Maria de Jesus, August 6, 1934; Huehuetenango, August 14, 

 1934. Honduras— Tela, August 19, 1930. Costa Rica— San Jose 

 (Cherrie), August 20; Carrillo (Carriker), September 1; San Isidro 

 de Coronado, September 8, 1935 ; Basin of El General, September 19, 

 1936; Vara Blanca, September 5, 1937; Murcia, September 11, 1941. 

 Panama — Canal Zone (Arbib and Loetscher), August 24, 1933, and 



