FAMILY ACCIPITRIDAE 213 



Usually these hawks show little fear, in many places being almost 

 foolishly tame, so that they are easy to approach, and they come 

 regularly to the squeaking sounds that the hunter makes to attract 

 small birds. Often they betray their presence by high-pitched, 

 querulous calls, repeated slowly, in imitation of which they are called 

 cuiscui. 



Following periods of rain, they sometimes rest in early morning 

 with partly spread wings and tail to enjoy the agreeable warmth of 

 the sun. In general they are of sluggish habit spending much time 

 at rest, making short flights only when disturbed. Though they may 

 soar in small circles, they do not rise high, and usually only con- 

 tinue for brief periods. 



Their principal food is composed of lizards, large Orthoptera, and 

 other insects, but may include an occasional small bird, usually a 

 young one, or a mouse. People living in the country complain that 

 individuals that range near houses capture small chicks, the only 

 damage that may be ascribed to them, as otherwise they appear harm- 

 less. 



The species is one of those found throughout much of the tropical 

 area of the Americas from Mexico to northern Argentina. There is 

 considerable variation in color in different sections, so that different 

 authorities have recognized between 15 and 20 races in the entire 

 range. Four of these subspecies are found in the Republic of 

 Panama. 



The species magnirostris uniformly has the webs of the primaries 

 and secondaries rufous, and so is readily known. It has been placed 

 by some authorities in a distinct genus Rupornis, which however 

 appears to have no trenchant characters when the many species of the 

 broad Buteo group are considered. 



Double ovaries are common in these birds, and undoubtedly have 

 led to the marking of some females in museum collections as males 

 by preparators not familiar with this condition. One female that I 

 took near Alanje, Chiriqui, March 3, 1960, had the right ovary 

 dormant, though of fair size, and ova in process of development in 

 the one on the left side. 



BUTEO MAGNIROSTRIS ARGUTUS (Peters and Griscom) 



Rupornis magnirostris arguta Peters and Griscom, Proc. New England Zool. 

 Club, vol. 11, Aug. 30, 1929, p. 46. (Almirante, Bocas del Toro, Panama.) 



Characters. — Distinctly brownish gray above and on foreneck and 

 upper breast; pale tail bands gray, or with slight rufous edging on 

 either side, adjacent to the black bands; light bars on lower surface 

 deeper buff. 



