FAMILY TYRANNIDAE 495 



Resident. Found locally in the Tropical Zone on the Pacific slope 

 from western Chiriqui (to 1340 meters elevation near El Volcan), 

 eastward in eastern Chiriqui, Veraguas, Code, and the Canal Zone to 

 the lower Rio Bayano (San Antonio) ; on the Caribbean slope in the 

 lower Chagres Valley in the Canal Zone. (To date it has not been 

 recorded on the Azuero Peninsula.) Islas del Rey, Saboga, San Jose, 

 and La Vivienda, in the Archipielago de las Perlas. 



In general appearance and actions these small birds appear similar 

 to species of the genus Empidonax. They are found usually at the 

 borders of thickets, often in brush-grown valleys but not in heavy 

 forest. Here they rest quietly on watch for flying insects which they 

 take on the wing. They also visit berry-bearing shrubs to eat the 

 drupes. The stomach of one shot near Corozal in the Canal Zone in 

 mid-June held fragments of several small beetles, a Lygaeid, ants, 

 and other hymenoptera. 



As the birds rest, the tail often is vibrated. The usual call is a low 

 wheesp varied to a quickly uttered little song, zvhee seety seety. 

 Eisenmann, in the suburbs of Panama City, heard them giving a 

 clear but monotonous repetition of a single note, zveeb, weeh, weeh. 

 Females, that I thought may have been near their nests, as they rested 

 on a low perch, occasionally fluttered the wings and uttered low 

 chattering calls. 



While found usually in the lowlands in western Chiriqui, they 

 ranged to 1340 meters near the Rio Chiriqui Viejo. In eastern 

 Chiriqui, Mrs. Davidson secured one near Chame. In Veraguas, 

 Arce collected them at Calovevora, which indicates occurrence on the 

 Caribbean slope. On the Pacific side they have been found at Santa 

 Fe, Castillo, and San Francisco. I saw and collected several near 

 Sona, and near Rio de Jesus. In Code, they ranged among bushes 

 in an abandoned field near El Valle, and below, in the edge of the 

 western sector of the Province of Panama along the road above 

 Espino. They were in pairs regularly and were in breeding condition 

 in April and May. 



In the Perlas Islands they were found on Isla San Jose, but we 

 did not fully realize their abundance until access trails to remote 

 areas of the island had been completed by the engineers. W. W. 

 Brown, Jr., collected the first specimens on Islas del Rey and Saboga; 

 Murphy (Auk, 1945, p. 117) secured a male on Isla Vivienda, May 

 23, 1941. 



This form extends to the west beyond Chiriqui in southwestern 

 Costa Rica, where Skutch (Pac. Coast Avif., no. 34, 1960, pp. 340- 



