FAMILY BUCCONIDAE 471 



wear on the tips of wing and tail feathers, indication that they are 

 occupying nest cavities. 



As they rest on their high perches both males and females occa- 

 sionally utter a series of low, twittering notes that blend in fairly 

 rapid repetition into a trilling song. To the ear of one familiar with 

 northern birds this is quite similar to the song of the pine warbler. 

 The sound is so insignificant compared with the stocky form of the 

 bird that when I first heard it I did not trace it immediately to its 

 proper source, though the songster rested in clear view, but instead 

 looked for some smaller species in the undergrowth. 



In the preparation of specimens, where the gonads of males were 

 somewhat developed I noted that the left one was definitely larger 

 than the right. In one instance it measured 7 mm. long by 5 broad, 

 with the companion only about 5 by 3 mm. In another, the right 

 gonad was 5 mm. long by 3 broad, while the left was only one-third 

 as large in bulk. 



Countrymen have a variety of names for this species, in addition 

 to the usual martin del monte. Boys with slingshots often called it 

 cabeza piedra because of its definite strength against these usually 

 lethal weapons. In Darien it was sometimes the aguanta piedra, less 

 often the correrio. One hunter who accompanied me often at La 

 Jagua, near Pacora, called it catinga. 



The name hyperrhynchus now covers the birds of this species over 

 most of Central America, Colombia, Ecuador, and Venezuela south 

 to northwesern Brazil. The typical form macrorhynchos, found in 

 eastern Venezuela from eastern Bolivar, the mouth of the Rio 

 Orinoco, and the Guianas south to northern Brazil (west to the Rio 

 Branco) differs in much narrower white band on the forehead. The 

 somewhat grayish population with rump and upper tail coverts 

 faintly barred with white of El Salvador and northwestern Nicaragua 

 has been described as the race cryptoleucus by van Rossem. 



NOTHARCHUS PECTORALIS (G. R. Gray) : Black-breasted 

 Puff bird; Martin Pechinegro 



Bucco pectoralis G. R. Gray, Gen. Birds, vol. 1, December 1846, pi. 26. (South 

 America = Middle Magdalena Valley, Colombia.) 



Like the white-necked puffbird but smaller, with black forehead; 

 black of breast extended on side of neck and cheeks to the bill. 



Description. — Length 210-235 mm. Adult (sexes alike), crown, 

 hindneck, upper back, breast, and side of neck glossy blue-black, 

 in some with a slight greenish sheen ; lower back, rump, upper tail 



