274 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



DENDROICA VIRENS (Gmelin): Black-throated Green Warbler, 

 Reinita Verdosa 



Motacilla virens Gmelin, 1789, Syst. Nat., 1(2), p. 985. (Philadelphia, Pennsyl- 

 vania.) 



Small; upper surface green; sides of head yellow; throat black; rest 

 of undersurface white. 



Description. — Length 104-117 mm. Adult male, crown, back, and 

 rump yellowish olive-green, slightly more yellowish on rump; upper 

 tail coverts black, broadly edged gray; wings black, with middle and 

 greater coverts tipped white, forming two bars, and remiges edged 

 gray on outer web and white on inner web; outer two pairs of rectrices 

 white with narrow blackish stripe on inner side of outer web, next pair 

 blackish with white spot on outer web, remaining pairs blackish or black 

 with outer web edged gray; lores, superciliary, and sides of head and 

 neck bright yellow; throat, breast, and flanks black, with feathers often 

 tipped white until I'ebruary; rest of undersurface white, with abdomen 

 tinged yellow; underwing coverts white. 



Female and immatures, like adult male but green of upper surface 

 slightly duller and black on undersurface less extensive. 



Measurements. — Males (10 from the breeding range, taken in May, 

 June, and July), wing 60.0-65.8 (62.4), tail 45.0-51.3 (48.2), oilmen 

 from base 9.3-11.6 (10.8), tarsus 12.8-18.8 (16.5) mm. 



Females (10 from the breeding range, taken in May, June, and July ) , 

 wing 57.0-61.7 (59.6), tail 44.6-51.4 (47.5), culmen from base 9.8-11.3 

 (10.6), tarsus 14.5-17.7 (16.6) mm. 



Migrant and winter visitor from the north. Common in the foothills 

 and highlands of Chiriqui and Veraguas, less regular but at times still 

 common in the hill country of central Panama; in the lowlands it oc- 

 curs only as a transient. Monniche (Blake, Fieldiana: Zool, vol. 36, no. 

 5, 1958, p. 558) collected this species on the Volcan de Chiriqui between 

 1500 and 2700 m; I have found it in this area at the same elevations, 

 and at Santa Clara at 1260 m. Farther east, I have found Black- 

 throated Green Warblers at El Cope in Code, at La Campana (60 m) 

 in the Province of Panama, and at Cerro Mali, Darien, where on March 

 1, 1964, I shot one at 1260 m on the south fork of the Rio Pucro. In 

 the Canal Zone this species is "rather rare" (Ridgely, 1976, p. 295) : 

 Lawrence (Ann. Lyc. Nat. Hist. New York, vol. 7, 1861, p. 293) re- 

 ported that McLeannan collected it on the Atlantic side near the Pan- 

 ama Railroad, but Willis and Eisenmann (Smiths. Contrib. Zool. no. 

 29, 1979) do not record it from Barro Colorado Island. 



Black-throated Green Warblers have been reported in Panama from 



