FAMILY ACCIPITRIDAE 2I9 



In such wild, unsettled areas as the forests adjacent to the Rio 

 Chucunaque these hawks show Httle fear, and on several occasions I 

 have had them fly down to perch near at hand in order to watch me 

 with evident curiosity, often with a low mewing call, kee-ee wee. 

 This note is heard also when they rise to soar above the trees, when 

 against the sky their white plumage often appears gray. 



Foremost in my recollections of the species is of an early morning 

 flight by helicopter across the lower slopes of Cerro Pirre, back of El 

 Real, in Darien, when in a quarter hour I covmted 20 of these beauti- 

 ful birds, singly or in pairs soaring over the forest far below us — 

 moving silhouettes of white, dark wing tips on either side, against 

 the deep green of the unbroken forest underneath. 



Their food is taken from such small mammals as mice, rats, and 

 small opossums, and from lizards, snakes, frogs, and large Orthop- 

 tera. Small birds do not seem troubled by their presence, and I have 

 never seen the hawk pay much attention to them. Van Tyne (Occ. 

 Pap. Mus. Zool. Michigan, no. 525, 1950, p. 6) records the basiliscus 

 lizard as regular prey. 



Chapman (Trop. Air Castle, 1929, pp. 60-61), on March 9, 1929, 

 found a nest on Barro Colorado Island placed in the top of a tall 

 tree. One of the pair rested beside it with a leafy green twig in its 

 bill. A female shot by E. A. Goldman near Gatun on February 3, 

 191 1, was nearly ready to lay. 



The preference of this species is for forested areas in rolling hill 

 country, and it originally appears to have been distributed throughout 

 the republic, except in the extensive savannas of the central and 

 western areas of the Pacific slope. I have not found it in the open 

 scrubs of the lowlands on the eastern side of the Azuero Peninsula, 

 or in the swampy woodlands near the coast. As land has been cleared 

 for cultivation these birds have disappeared. 



The body plumage is long and heavy, and there is much under 

 down, so that these birds appear much larger in body than is actually 

 the case. This may be a protective device since, though tropical tem- 

 peratures may not register low in terms of degrees on a thermometer, 

 when the air is humid it often becomes chill. As the animals that 

 form the food of the gavildn bianco usually are large enough so that 

 one constitutes a meal, or as smaller prey is so common that it is 

 easy to capture several, the hawk after eating may remain inactive 

 for considerable periods, and so need this insulation. The plumage 

 is so dense, in fact, that it serves almost like a protective armor that 

 guards the body against injury by the pellets in a shot gun charge 

 when the birds are at any distance. 



