334 BIRDS OF THE REPUBLIC OF PANAMA PART 2 



Females (10 from Panama), wing 53.8-60.1 (55.8), tail 31.0-34.6 

 (32.5), culmen from base 23.3-24.8 (23.6) mm. 



Weight, 12 males, 5.40±0.10 grams; 10 females, 472±0.10 grams 

 (Hartman, Auk, 1954, p. 468). 



Resident. Common throughout the tropical lowlands, from the 

 Costa Rican boundary in Chiriqui and Bocas del Toro eastward, in 

 lesser number in open areas of the Subtropical Zone to 1,600 meters 

 on Volcan de Chiriqui, and to 1,000 meters in the Azuero Peninsula. 

 Found on islands in the Gulf of Chiriqui (Parida, Bolanos, Brincanco, 

 Canal de Afuera, Afuerita), Isla Coiba, Isla Rancheria, Isla Cebaco, 

 Isla Gobernadora; islands in Laguna de Chiriqui (Colon, Pastores, 

 San Cristobal, Bastamientos, Agua) ; Isla Taboga. Common on the 

 Pacific slope to the eastern Province of Panama (Chepo, El Llano), 

 and on the Caribbean side through the Chagres Valley (to Candelaria 

 on the Rio Pequeni, and Peluca on the Rio Boqueron), and along 

 the coast to Portobelo in eastern Colon. 



While I have found no records from Darien or San Bias, the bird 

 may occur there as the species is widely distributed in northwestern 

 Colombia including northern Choco (recorded at Unguia). In view 

 of the occurrence on islands off the Pacific side of western Panama 

 it is interesting that this species does not extend to the Archipielago 

 de las Perlas. 



The rufous-brown tail, clearly visible as the bird feeds in low 

 shrubbery, identifies this species, the most widely distributed of its 

 family in the lowlands of the Isthmus. In wilder areas these hummers 

 are found along streams, back of beaches, and in more open border 

 areas in general. Less often they may range in forests from near the 

 ground to the more open air of the high tree crown. They are flower 

 feeders and gleaners of insects on leaves and branches, and so find 

 the borders of cultivated fields, low rastrojo, and other open areas 

 attractive. These preferences draw them naturally to flowers planted 

 about houses, so that it is common to see them in gardens and in 

 plaza or park areas in towns. Smaller flowers are probed with the 

 long bill as they hover on the wing. With those of larger size the 

 hummers frequently perch on ends of the petals, or on adjacent 

 blossoms, for ready access to these supplies of food. The stomach of 

 1 specimen taken at Portobelo held 3 small spiders and 5 myrmecine 

 ants. 



Males display from a perch in the sun, with spread tail and 

 fluttering wings, while they utter a chirping, twittering song. They 

 often chatter with double-noted calls when disturbed by entry in their 



