IQO BIRDS OF THE REPUBLIC OF PANAMA PART 3 



Caribbean side, east to the Colombian boundary in Darien and San 

 Bias ; in the mountains to 550 meters on the upper Rio Tacarcuna and 

 575 meters at Cana, on Cerro Pirre. 



Beyond, in Colombia, this form ranges in Choco (Acandi, Unguia) 

 to the lower Atrato Valley and southwest of the western Andes to 

 Punto Muchimbo, Valle, and western Narino (Barbacoas). 



In heavy forest in Darien it is found in the undergrowth. It is 

 adaptable as where there are abandoned clearings it may be found in 

 rastrojo. 



The food is insects. Several stomachs that I have examined held 

 orthopteran remains, the egg case of a roach, the head and mouth- 

 parts of a moth, bits of caterpillar skin, fragments of ants, a snout 

 beetle, cerambycids. and other beetles, and remains of spiders. 



The entire population assigned to nifivcntris is merely a transition 

 from the dark northern crepcra to typical Cercomacra tyrannina 

 tyrannina, found through most of Colombia, southern Venezuela and 

 northwestern Brazil, with its type locality in the Bogota area. In fact, 

 occasional specimens in the area assigned to rufiventris are as pale as 

 the average of tyrannina. Most, however, are slightly darker. 



The type of the race was collected by McLeannan and Galbraith. 



On Barro Colorado Island, Skutch found a nest on April 29, 1935. 



CERCOMACRA NIGRICANS Sclater: Jet Ant-bird, Hormiguerito 



Azabache 



Cercomacra nigricans P. L. Sclater, Proc. Zool. Soc. London, pt. 26, November 

 9, 1858, p. 245. (Santa Marta, Magdalena, Colombia.) 



Rather small ; male black with wing coverts and tail tipped with 

 white ; female slate to blackish slate, under surface lined narrowly 

 with white. 



Description. — Length 145-160 mm. Adult male, deep black; 

 upper lesser wing coverts wholly white ; tail tipped with white ; alula 

 and outer primary with outer web edged with white : under wing 

 coverts black, edged broadly or barred posteriorly with white; a 

 broad patch of white in center of back, concealed by black tips of the 

 feathers. 



Adult female, blackish slate to slate ; under surface from side of 

 head and throat to abdomen lined and sometimes barred with white, 

 the amount variable, in some extensive ; wing, including under 

 surface, tail and concealed back patch white as in male, but with 

 the concealed marking less extensive. 



Immature male, like female. 



Juvenile (a male from Department of Magdalena, Colombia), dull 



