200 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



Darien and San Bias, in our series from Colombia I find specimens 

 exactly similar to those of Panama from the lower Magdalena Valley 

 in the Department of Bolivar (Santa Rosa, Rio Viejo, Norosi, 

 Coloso, Coveiias), adjacent Cordoba (Pueblo Nuevo), and Mag- 

 dalena (La Gloria, Ayacucho, and along the Rio Cesar). 



MYRMECIZA EXSUL Sclater: Chestnut-backed Ant-bird, 

 Hormiguero Lomo Castano 



Size medium, with heavy body and short tail ; like a wren in action ; 

 head black to slate color, body brown. 



Description. — Length 130-150 mm. Adult male, crown and hind- 

 neck black to slate-black ; rest of upper surface, including wings, 

 chestnut ; tail faintly duller ; wing coverts plain, or spotted more or 

 less with white, the anterior lesser series margined with white; 

 anterior under surface black to blackish slate or slate ; flanks and 

 under tail coverts, and in some the lower abdomen, chestnut to duller 

 brown ; under wing coverts mixed white and black. 



Adult female, upper surface as in male, but colors of crown and 

 hindneck duller ; side of head, chin, and throat slate to slate-black ; 

 rest of under surface plain brown ; under wing coverts as in male. 



Juvenile male, like adult, but colors duller, the brown area mixed 

 more or less with sooty brown to sooty black. 



This is one of the common ant-birds of the Tropical Zone forests, 

 where it ranges from the lowlands to elevations of 600 to 700 meters. 

 The birds normally are found in pairs that move on or near the 

 ground in the undergrowth of the forest floor, seldom ascending 

 more than a meter or so among the branches. They are common 

 in swampy woodlands, or along small quebradas, and are found also 

 in drier areas. Though their proper haunt is in forested land they are 

 able to adapt to life in rastrojo where the larger growth has developed 

 fair-sized trees. Often they are found in such deeply shaded areas 

 that they are detected only in movement, since at rest their dark 

 colors render them invisible. As they travel, they examine tangles 

 of leaves that may conceal insects, walking when on the ground, 

 hopping rather slowly through the branches above. 



Males call at short intervals — a clear, double-noted whistle, that 

 often is repeated by the female in slightly different tone. The note 

 is easily imitated, when the birds are attracted and come near. At 

 such times they may become disturbed and utter chattering calls. 

 Then as they approach, whistling and scolding, the feathers of the 

 rump and lower back are raised, and the tail is vibrated. Occasionally 



