FAMILY VIREONIDAE 



24I 



buprestid 3%, 25 seeds of Melastomaceae 5%. Another collected Feb- 

 ruary 14, 1912, at Empire contained one hairy and one smooth cater- 

 pillar skin, both small 20%, 10 seeds of Panicum sp. and other vegeta- 

 ble fragments 80%. Of several taken by Strauch (Bull. Brit. Orn. 

 Club, 1977, p. 64), 5 males ranged in weight from 11.3 to 13.0 g, and 6 

 females from 11.4 to 13.7 g. 



HYLOPHILUS FLAVIPES XUTHUS Wetmore 



Hylophilus flavipes xuthus Wetmore, 1957, Smiths. Misc. Coll., 1943 (9), p. 85. 

 (Isla Coiba, Panama.) 



Characters. — Undersurface much darker, more buffy (instead of 

 yellow), sides darker; darker green above than H. f. viridiflavus; bill 

 heavier. Immature darker above and below, with wash of ochraceous- 

 orange on abdomen. 



Measurements. — Males (7 from Isla Coiba), wing 55.8-58.3 (57.5), 

 tail 47.0-50.9 (48.4), oilmen from base 14.3-15.0 (14.7), tarsus 17.9- 

 19.0 (18.6) mm. 



Females (6 from Isla Coiba), wing 54.4-56.7 (55.9), tail 45.2-49.3 

 (47.8), culmen from base 14.6-16.1 (15.1), tarsus 18.2-19.4 (18.6) 

 mm. 



Resident. On Isla Coiba these were among the more common of the 

 small birds, though seen infrequently because they ranged among 

 screening leaves and creepers. During my visit from January 6 to 

 February 6, 1956, they were found in the scrub growths back of the 

 beaches and at the borders of mangroves, and came also into the brushy 

 rastrojo of old fields, habitats similar to those inhabited by other forms 

 of the species in mainland localities. On Coiba, I found that they also 

 lived in the high crown of the inland forest, though it was near the end 

 of my stay before I verified this, owing to the difficulty to detecting 

 small birds in such situations. They move actively among the leaves 

 and twigs, almost as quickly as wood warblers, and when seen often 

 appear very close at hand. Occasionally I found them feeding on small 

 drupes of fruiting trees. The yellowish-white iris of the adult birds is 

 often apparent as they climb and hop among the smaller branches. The 

 darker colored immature birds have dark eyes. The song, given in low 

 tones, usually has three similar notes, swee, swee, swee, which are easily 

 imitated by whistling. 



The birds of Coiba are much darker than the nearby mainland race 

 and the bill is heavier at the base than in viridiflavus in addition to being 

 slightly longer. 



