i8 4 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



Description. — Length 105-118 mm. Adult (sexes alike), crown 

 and hindneck dark olive-brown; back and wings grayish olive; sec- 

 ondaries and inner primaries edged cinnamon; tail graduated, blackish 

 with all but central pair of feathers tipped white; facial area and sides 

 of breast bright cinnamon; throat white with some dusky markings, 

 varying in prominence; rest of undersurface buffy. 



Juvenile, like adult, but upper surface browner, undersurface pale 

 grayish brown. 



A male taken March 25, 1961, at Pacora, Province of Panama, had 

 the iris light wood brown; maxilla and line on side of mandible fuscous- 

 brown; rest of mandible pale brownish white; tarsus and toes dark 

 neutral gray. 



Another bird taken at Canita, Province of Panama, had the iris dull 

 brownish gray; maxilla fuscous, except base of culmen which is 

 fuscous-black; rami brownish white; rest of mandible fuscous-brown; 

 tarsus, toes, and claws neutral gray. 



Measurements. — Males (10 from Herrera, Province of Panama, 

 Los Santos, San Bias, and Darien), wing 47.5-54.0 (50.0), tail 37.4- 

 48.2 (41.7), culmen from base 22.7-25.7 (23.9), tarsus 19.3-21.1 

 (20.1) mm. 



Females (10 from Herrera, Los Santos, Province of Panama, and 

 Darien), wing 46.6-51.5 (48.5), tail 33.5-39.0 (37.3), culmen from 

 base 21.6-24.8 (23.5), tarsus 19.7-21.8 (20.7) mm. 



Resident. Widespread and fairly common in the lower growth of 

 forest edges, second-growth woodlands, and damp thickets of fairly 

 humid lowlands through most of Panama. The range of rufiventris 

 extends from southeastern Mexico to Colombia; other forms are found 

 south through Brazil and Peru. In Panama, Ramphocaenus is usually 

 found up to 1050 m (Ridgely, 1976, p. 280), but Frank Hartman col- 

 lected a male at 1200 m on Cerro Pando, Chiriqui, on March 11, 1951 

 (now in collection of Ohio State University) . On the western slope of 

 the Azuero Peninsula, Aldrich and Bole (Scient. Publ. Cleveland Mus. 

 Nat. History, vol. 7, 1937, p. 25) found it uncommon in humid forest 

 of the Tropical Zone (300-900 m). In the Canal Zone, Eisenmann 

 (Smiths. Misc. Coll., vol. 117, no. 5, 1952, p. 48) found it "fairly com- 

 mon in thickets in the lighter woods." 



The Smithsonian has specimens from Bocas del Toro at Almirante; 

 Chiriqui at Puerto Armuelles; Veraguas at Sona and Santa Fe; on 

 the eastern side of the Azuero Peninsula at Punta Mala and Pedasi in 

 Los Santos, and Pese and El Barrero in Herrera; El Uracillo in Code; 

 in the Province of Panama and Canal Zone at several localities from 



