FAMILY TROCHILIDAE 345 



Females (10 from Panama), wing 62.0-64.6 (63.4), tail 36.6-39.4 

 (38.0), oilmen from base 25.6-27.4 (26.1) mm. 



Weight, 1 female 5.6 grams (Hartman, Auk, 1954, p. 468.) 



Resident. Fairly common in the Pacific lowlands from the Province 

 of Panama (west to La Campana), and the Canal Zone, east to Cerro 

 Sapo, and the Sambu, Tuira, and Chucunaque valleys, in Darien; 

 ranging in the Canal Zone to the Caribbean slope in the lower Chagres 

 Valley (Juan Mina, Barro Colorado Island) ; to 600 meters elevation 

 on Cerro Pirre (Cana). 



This is a bird of the forest that in the savanna areas ranges among 

 the trees that line the water courses or border swampy areas. Below 

 Chepo, in the area called Porcada Valdez, I found them around the 

 blossoming guayavas; and elsewhere saw them feeding at various 

 flowers in the undergrowth. As they move the broad white feathers 

 of the undertail coverts at times stand out clearly, a striking mark of 

 identification. From the stomachs of 3 that Goldman collected at 

 Cana I identified remains of small insects, among which were beetle 

 fragments of the families Hydrophilidae and Scolytidae, many small 

 hymenoptera and diptera, and bits of a jassid. 



As a species. Chalybura buffonii ranges from central Panama 

 through northern and central Colombia to western Venezuela. The 

 population of Panama appears distinct in the dark, deeper blue of the 

 central rectrices in both sexes. In a few individuals that I have seen 

 these feathers have a faint edging of dull green, but this of slight 

 amount. Adult males, compared with skins from central and northern 

 Colombia, also are more bluish green on the lower surface. Adult 

 females from Panama are clearer white on the foreneck, breast, and 

 abdomen. According to De Schauensee the race micans extends into 

 northwestern Colombia. 



Lesson (Les Trochilidees, 1832, p. 31, pi. 5) described Trochilus 

 buffonii from a specimen of unknown locality which he believed came 

 from Brazil, erroneously, however, as the species is not found that 

 far south. Hellmayr and Seilern (Arch. Naturg., vol. 78a, pt. 5, 1912, 

 p. 140) recognized this error, and as the original description and 

 figure agreed with trade skins from Bogota, designated that area as 

 the type locality. Bogota trade skins, and modern specimens from 

 central Colombia that I have seen have the central rectrices bordered 

 definitely with bronze to dull bronze-green. These are identified as the 

 typical subspecies C. b. buffonii. 



Todd (Ann. Carnegie Mus., vol. 29, 1942, pp. 331-332) from 

 rather limited material has argued that Lesson's description and figure 



