416 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



in the British Museum show an intermediate stage toward oresbia, in 

 the darker throat, somewhat duller yellow of lower surface, and duller 

 color above. 



Females I collected at El Volcan, Chiriqui, on February 12 and 23, 

 1960, were ready to lay. In Costa Rica, Skutch (Pac. Coast Avif. no. 

 31, 1954, pp. 226-234) found nests with eggs of this race from March 

 to August. The cup-shaped nest is built of moss, small ferns, and other 

 similar plant materials, with a lining of dry leaves and plant fibers; it 

 is placed in a tree from 2 to 12 m from the ground. Only some males 

 assist their mate in construction, which takes 4 or 5 days. 



The clutch is two, the eggs being "dull white or grayish, rather 

 heavily mottled all over with brown. The markings are most concen- 

 trated on the thicker end, where on some eggs they nearly conceal the 

 ground color. The measurements of 8 eggs average 21.3 by 15.6 mil- 

 limeters." The incubation period is 14 days. Both parents feed the 

 young, which remain in the nest approximately 15 days; after fledging, 

 the young leave their parents sooner than do other members of the 

 genus Tangara that Skutch has observed. 



TANGARA ICTEROCEPHALA ORESBIA Wetmore 



Tangara icterocephala oresbia Wetmore, Smiths. Misc. Coll., vol. 149, no. 1, June 

 26, 1962, p. 9. (South face of Cerro Campana, 850 m., Province of Panama, 

 Panama.) 



Characters. — Decidedly darker than either T. i. frantzii or T. i. 

 icterocephala; yellow coloration darker throughout; band on hindneck 

 more greenish blue; foreneck and throat darker; sides and flanks dark- 

 er, with a greenish yellow cast. Females have the edging on the back 

 feathers greener, less yellowish. 



Measurements. — Males (8 from Code and Province of Panama), 

 wing 72.4-77.4 (73.6), tail 45.8-47.7 (47.3), culmen from base 12.0- 

 14.8 (12.9), tarsus 17.5-18.8 (18.3) mm. 



Females (9 from Code and Province of Panama), wing 68.7-72.4 

 (71.1), tail 43.5-47.6 (45.6), culmen from base 12.5-14.0 (13.2, aver- 

 age of 8), tarsus 17.8-18.8 (18.3) mm. 



Resident. Common from the mountains of Code near El Valle 

 east through the Province of Panama to Cerro Campana, where it has 

 been seen in large flocks of several dozen or more (Ridgely, 1976, p. 

 317). 



The darker coloration of both sexes suggests the duller colors seen 

 in females of the other races of this species. Above El Valle, I found 



