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BIRDS OF THE REPUBLIC OF PANAMA PART 4 



species in Panama. Skutch (Pac. Coast Avif., no. 31, 1954, pp. 217- 

 225) has found several nests in Costa Rica. The earliest was being 

 built on April 10 and the latest had eggs on June 18. The nest is a com- 

 pact cup, with an exterior made primarily of the rachides of the leaves of 

 a mimosa and a few rootlets and strips of banana leaves; a typical in- 

 terior had more strips of banana leaves, pieces of dicotyledonous leaf, 

 black fungal hyphae, and a few horsehairs, with gray foliaceous lichen 

 in the bottom of the cup. The nests Skutch found measured 7.6 to 8.9 

 cm in over-all diameter, 5.1 to 7 cm in height, 5.1 to 5.7 cm in inside 

 diameter, and 3.2 to 3.8 cm in depth. The nest is placed in a leafy sec- 

 tion of a small tree between 3 and 8 m from the ground; both male and 

 female assist in its construction, which requires 3 days. 



Each nest held two eggs; they were white, heavily mottled with 

 brown, especially on the larger end. One measured 20.6x15.1 mm. 

 Incubation is performed only by the female and takes 13 days; during 

 this time she is fed by the male. Both parents feed the young a diet of 

 fruit and insects. At 15 days the young leave the nest. 



TANGARA ICTEROCEPHALA (BonaparteJ: Silver-throated Tanager, 

 Tangaro Cabeciamarillo 



Small; head, lower back, rump and most of undersurface bright yel- 

 low; upper back streaked yellow and black; wings and tail black, edged 

 bright green. 



Description. — Length 125-130 mm. Adult male, crown, orbital ring, 

 lower back, and rump brilliant, rich yellow; upper back black, edged 

 rich yellow, creating streaked appearance; upper tail coverts yellow- 

 green; wing black, with lesser and middle coverts tipped rich yellow, 

 outer webs of greater coverts and remiges edged brilliant yellow-green; 

 lores, line on head below eye, and auricular region black; point of chin 

 black; throat and upper breast pale green; rest of undersurface rich 

 yellow; bend of wing yellow; underwing coverts white and gray. 



Adult, female, like male, but duller, more greenish. 



Juvenile, duller than female, with the black lines on the head ob- 

 scure, and the throat, breast, and crown dull yellowish green. 



The Silver-throated Tanager is common in forests and forest borders 

 in the foothills and highlands of both slopes, usually between 600 and 

 1800 m, but in Chiriqui occasionally as high as 2250 m. It is sometimes 

 part of the mixed flocks that move through the forest feeding on in- 

 sects and fruit, although Buskirk et al. (Auk, 1972, p. 620) found that 

 at Cerro Punta, Chiriqui, this species would join such flocks but not 

 follow them. In Colombia, Hilty (Wilson, Bull., 1974, p. 480) saw a 



