FAMILY FORMICARIIDAE 187 



tipped narrowly with white (this often wholly lost through wear). 



Adult female, above olive to grayish olive ; wings dusky-brown, 

 edged narrowly with olive to ochraceous-olive ; alula edged with buff ; 

 in some, the wing coverts, especially the greater row, tipped lightly 

 with ochraceous ; tail also darker ; lores and in some the nasal capsule 

 feathering ochraceous ; side of head, in some the ramal area, mixed 

 olive and tawny-ochraceous ; chin and upper throat ochraceous ; 

 lower throat, breast, abdomen, under tail coverts, and tibia tawny- 

 ochraceous ; sides and flanks strongly olive ; under wing coverts and 

 inner edging of primaries and secondaries buff to ochraceous. 



Immature male, like female but averaging darker. 



These are quiet birds of forests in the Tropical Zone, found in 

 pairs, and located mainly through the low trilling song of the male, 

 a quiet repetition of a single note, heard usually from behind thin 

 screens of slender vines that cloak shrubs and the lower trees. When 

 located by their notes usually they decoy easily. In addition to the 

 song they have low sibilant calls, varied occasionally to chattering 

 notes. 



Little has been recorded of the habits of these birds. Two sub- 

 species are found in the Republic. 



CERCOMACRA TYRANNINA CREPERA Bangs 



Cercomacra crcpcra Bangs, Auk, vol. 18, no. 4, October 1901, p. 365. (Divala, 

 Chiriqui, Panama.) 



Characters. — Darker ; adult male, above dull black to blackish 

 slate ; under surface dark slate to blackish slate. Females darker above, 

 and deeper tawny below. 



A male, taken near El Volcan, March 14, 1965, had the iris light 

 mouse brown ; bill black ; tarsus, toes, and claws dark neutral gray. 



In a female, secured at Puerto Armuelles, Chiriqui, February 1, 

 1966, the iris was brownish gray ; maxilla fuscous-black, with the 

 cutting edge brownish gray ; side of mandible dull neutral gray ; gonys 

 pale brownish white ; cutting edge and gape dull honey yellow ; tarsus 

 and toes as in male. 



Measurements. — Males (10 from Chiriqui and Bocas del Toro), 

 wing 61.9-65.2 (63.5), tail 53.4-61.0 (56.3), culmen from base 

 17.6-19.8 (19.0), tarsus 21.9-23.0 (22.5) mm. 



Females (10 from Chiriqui, Veraguas, Bocas del Toro, and Costa 

 Rica), wing 59.0-63.3 (61.3), tail 52.1-59.1 (57.2, average of 9), 

 culmen from base 17.4-18.8 (18.1), tarsus 21.0-23.8 (22.2) mm. 



Resident. Fairly common, mainly in Tropical Zone forests on both 



