6i8 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



The grass-finch inhabits grasslands and grassy hillsides. When 

 flushed, it flies low over the grasses and then drops down again, being 

 difficult to relocate. Nothing appears to be known of its life history. It 

 has two songs, "a musical tleedee, tleedee, tleedee with variations, and a 

 very different buzzy tzit-zeereea or zit-zipzirree" (Ridgely, 1976, p. 

 340). When singing, the bird usually perches in the open on a fence 

 post or the top of a grass clump. 



Taxonomy of this genus and the little known of its ecology are dis- 

 cussed by Eisenmann and Short (Amer. Mus. Novit. no. 2740, 1982, 

 pp. 20-21). 



CARDUELIS XANTHOGASTRA XANTHOGASTRA (Du Bus): 

 Yellow-bellied Siskin, Pinzon Ventriamarillo 



Chrysomitris xanthogastra Du Bus, 1855, Bull. Acad. Roy. Sci. Bruxelles, 22, pt. 1, 

 p. 152. (Ocana, Colombia.) 



Very small; male, throat, breast, and upper surface black except for 

 patch of bright yellow at base of remiges and rectrices; remainder of 

 undersurface bright yellow; female mostly yellowish green with patch 

 of yellow at base of black remiges and rectrices. 



Description. — Length 97-108 mm. Adult male, throat, breast, and 

 entire upper surface including wings and tail black, except for patches 

 of bright yellow on basal third to half of both inner and outer webs of 

 remiges and rectrices; remainder of lower surface rich yellow; under- 

 wing coverts pale yellow. 



Adult female, throat, breast, and entire upper surface dark olive; 

 wing coverts black, tipped dark olive; remiges and rectrices like male's, 

 but yellow slightly less extensive; sides and flanks yellowish green, be- 

 coming more yellowish at center of belly; abdomen and undertail co- 

 verts whitish; underwing coverts white, tinged light yellow. 



Measurements. — Males (10 from Chiriqui and Costa Rica), wing 

 64.0-66.8 (65.3), tail 36.4-43.0 (39.3), oilmen from base 9.9-11.4 

 (10.7), tarsus 12.7-14.8 (13.6) mm. 



Females (10 from Chiriqui, Costa Rica, and Colombia), wing 61.0- 

 66.3 (63.9), tail 33.9-39.8 (37.7), culmen from base 9.2-10.8 (10.1), 

 tarsus 12.0-15.6 (13.5) mm. 



Resident. Fairly common in the highlands of western Chiriqui; 

 elsewhere it occurs in Costa Rica and from Venezuela to western Ecu- 

 ador; another race is found in central Bolivia. In Panama, Monniche 

 (Blake, Fieldiana: Zool., vol. 36, no. 5, 1958) collected it on Volcan 

 de Chiriqui between 1560 and 1800 m. I have found it at similar eleva- 

 tions on Cerro Punta, and it has also been collected at Boquete. Ridgely 



