FAMILY TROCHILIDAE 317 



lowlands of central Panama to the Atlantic side through the lower 

 Rio Chagres (Barro Colorado Island, Gatun, Mount Hope, Colon) 

 and then continues east through eastern Colon (Portobelo) and San 

 Bias. I found it near Mandinga in 1957, and there are numerous 

 records to the east at Perme and Puerto Obaldia. Griscom described 

 a race confinis from this area, but with more material this is found not 

 to be separable. In Colombia the typical form ranges to the lower 

 Atrato Valley and the eastern shore of Golfo de Darien (Necocli). 

 It was interesting to find them fairly common in the lowlands of 

 Isla Coiba and on Isla Cebaco, as they do not occur on Taboga or other 

 island groups offshore. 



These birds range around shrubbery and open groves, and in 

 forested areas are found along the borders. While they may rest 

 on shaded perches, they range into the sun in the open to feed at 

 flowers. The forehead regularly carries pollen grains, occasionally 

 in such an amount that the feathers appear yellow. They also glean 

 insects from leaves and weed stems. At sunrise I have seen them 

 bathing in dew accumulated on vegetation during the night, brushing 

 back and forth over leaves until the breast was wet, and then perching 

 to preen and arrange their plumage. 



At Mandinga, San Bias, on January 23 and 25, 1957, I found 

 2 nests of this species, both placed in little forks in the tops of dry 

 weeds a meter tall that projected above a stand of grass. This grew 

 completely in the open in a broad clearing prepared for a fighter 

 plane airstrip during World War II. The nests were the usual open 

 cups, so placed that they were clearly visible at a distance of 75 meters. 

 They were made of light-colored plant downs, deeply cupped, and 

 were covered externally with bits of lichen and dead leaf. Each held 

 2 white eggs, obviously so far along in incubation that it was useless 

 to collect them. At hatching the young had a line of cinnamon- 

 colored down on either side of the back but otherwise were naked. 

 The egg shells were not removed from the nest, but were so fragile 

 that the weight of the young birds soon broke them into tiny frag- 

 ments. Growth was amazingly rapid as within 3 days the first 2 

 nestlings were at least four times their bulk on hatching, with heads 

 as large as the original eggs. On February 4 the first 2 were develop- 

 ing pin feathers, and on February 7 had the back covered with green 

 feathers. On February 12 they filled the nest completely with bill 

 and tail projecting. As I looked at them, suddenly both took wing, 

 one to perch immediately on a grass stem 15 meters distant, while the 

 other turned to hover in the wind for half a minute before it settled 



