FAMILY FORMICARIIDAE lOl 



Resident. Found in the tropical lowlands in western and central 

 Panama ; recorded on both slopes though more widespread on the 

 Caribbean side. Recorded in western Chiriqui, from Puerto Ar- 

 muelles, Bugaba, and Divala ; appears again on Cerro Azul, the lower 

 Rio Bayano (Cafiita) ; intergrades with M. q. consobrina on the Rio 

 Chiman and Rio Maje; distributed on the Caribbean side from the 

 Costa Rican boundary in Bocas del Toro, east through the northern 

 Canal Zone, the lower Chagres Valley above Madden Lake, and 

 western San Bias (Mandinga). 



In Chiriqui, Arce collected this bird near Bugaba a hundred years 

 ago (Salvin, Proc. Zool. Soc. London, 1870. p. 195), and W. W. 

 Brown, Jr., found it at Divala in November and December, 1900 

 (Bangs, Auk, 1901, p. 365). Specimens in the California Academy 

 of Sciences from Puerto Armuelles were taken in 1929 by Mrs. M. E. 

 Davidson. In 1966, I found a few in that area, inland adjacent to 

 the hills on the Costa Rican boundary, but elsewhere did not encounter 

 it as the forests in the lowland area had been cut except along the 

 streams. 



On the Caribbean side, it is a common species through the forests 

 in the lowlands and the lower foothills. I found it common near 

 Almirante, Bocas del Toro, in 1958, and on the Rio Indio, western 

 Colon, inland to the foothills on the Caribbean slope of Code. It is 

 seen regularly through the northern Canal Zone, and the lower 

 Chagres Valley to western San Bias at Mandinga. The single speci- 

 men taken by Goldman on Cerro Bruja appears to be intermediate 

 toward the following subspecies. At Cerro Azul it appears on the 

 Pacific slope, and continues through the eastern sector of the 

 Province of Panama to the lower Rio Bayano at Cafiita and east to 

 the Rio Maje and Cerro Chucanti where it intergrades with the race 

 consobrina. 



These birds are common on Barro Colorado Island in the Canal 

 Zone, where Skutch found them nest-building on February 22, 1935. 

 Here R. A. Johnson saw them ranging briefly over raiding swarms 

 of ants. He reported a nest found February 5, 1948 (Auk, 1953, 

 p. 496) in a small bush in the forest slightly more than a meter above 

 the ground. It was "a deep cup, with thick sides, suspended from the 

 fork of two branches . . . composed of dead leaves bound together 

 with plant fibers and lined with finer black fibers." It measured 

 in outside diameter approximately 75 mm, inside diameter 45 mm, 

 and inside depth 45 mm. The two eggs were "white with small brown 

 spots over the entire surface and with heavier blotches around the 



