192 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



Mus. Comp. ZooL, vol. 69, 1929, p. 168) received three males from 

 Cana on Cerro Pirre, taken by Benson in 1928. I have not found 

 it in work in the Tuira-Chucunaque Valley. On the Caribbean side 

 it was fairly common near Mandinga, western San Bias, in January 

 and February 1957. In the Archipielago de las Perlas it is common 

 on Isla del Rey and adjacent Isla Cafias. Bovallius collected male and 

 female on Isla Viveros in April 1882 (Rendahl, Ark. Zool, 1920, 

 p. 42). 



This interesting ant-bird normally lives in the forest undergrowth, 

 though it may range higher in the trees, possibly when drupes are 

 ripening. The usual food is comprised of small insects — beetles, bugs, 

 and ants, also spiders, but vegetable matter may be found in the 

 stomach. 



The presence of this ant-bird may be announced by a wrenlike call 

 ker check, ker check, or modified to a rapidly repeated chee kd, 

 chee kd, chee kd. As they move about, male and female in company, 

 the long tail with its white tip is vibrated regularly. Males may 

 display by spreading the depressed tail and moving it slowly. Where 

 common, they often show definite curiosity regarding a human 

 intruder, and usually decoy easily. 



Sclater and Salvin (Proc. Zool. Soc. London, 1879, p. 526) quote 

 T. K. Salmon's description of a nest found near Remedios, Antioquia 

 (northwestern Colombia) as made of dry grasses and placed in a 

 fork in low bushes. The two eggs, now in the British Museum 

 (Natural History) and described rather uncritically by the authors 

 as "mahogany-colour." I found on personal examination to have a 

 pinkish ground color, so heavily overlaid with smeared blotches, spots, 

 and lines of reddish brown to lilac-gray as to be almost obscured. In 

 form they were elliptical, with the measurements 21.4x15.2 and 

 21.5x14.9 mm. 



The species is widely distributed from Colombia and northern 

 Venezuela to western Ecuador and northern Brazil, a broad area but 

 one in which the bird remains remarkably uniform. It is especially 

 interesting that the population of the Perlas Islands appears identical 

 with that of the mainland. 



GYMNOCICHLA NUDICEPS (Cassin) : Bare-crowned Ant-bird, 

 Hormiguero Frentipelado 



Figure 17 



Size medium, with stout body and short tail ; male black, forepart 

 of head without feathers, the skin bright blue ; female olive-brown to 

 russet-brown. 



