FAMILY CORVIDAE 



41 



The nest is a fairly compact mass of leaves, straws, and similar ma- 

 terials, with a depression in the upper side for the eggs. These are white 

 and may be from 4 to 6 in number. Most of the published observations 

 of nesting in this swallow deal with the form or forms found in Guate- 

 mala or in Trinidad. According to Belcher and Smooker (Ibis, 1937, 

 pp. 506-507), the subspecies aequalis of Trinidad, similar in size and 

 color pattern to uropygialis of Panama but with whiter rump, white 

 edgings on the longer secondaries and inner primaries, lighter breast 

 and yellow abdomen, has the eggs "immaculate white, smooth-shelled 

 and slightly glossy." A set of 3 measured 18x13, 19x13, and 18.5 X 

 12.5 mm. The measurements cited for the race uropygialis in Schon- 

 wetter, Handbuch der Oologie (Lief. 17, 1970, p. 194), of 18.5-20.3 X 

 13.0-14.5 mm, average somewhat larger. 



The colors recorded in the description above are those typical of 

 uropygialis in Panama from Darien and San Bias west on both Carib- 

 bean and Pacific slopes through Veraguas; beyond, through Chiriqm 

 and Bocas del Toro, and continuing in Costa Rica and Nicaragua to 

 southeastern Honduras (Howell, Condor, 1972, p. 326). In addition, 

 there is much individual variation toward the duller colored subspecies 

 fulvipennis, found in typical form farther north in Central America. 

 These individuals, with variable, generally paler coloration, were sepa- 

 rated by Griscom as another race, decolor. They are found regularly 

 through the western sector of the Panama range of the normally colored 

 uropygialis and appear to have no valid racial status. 



Family CORVIDAE: Crows and Jays, Cuervos y Urracas 



The Corvidae, a family of more than 100 species, are distributed 

 widely through all continents of the World, except Antarctica. It is 

 interesting that the prominent crow-raven group, of large size and 

 mainly black color, found through much of the Old World, even to 

 Australia, in the Americas does not extend south beyond northwestern 

 Nicaragua. The smaller jays range into South America as far as Bo- 

 livia. 



The jays are omnivorous and feed adeptly in a variety of fashions, 

 even pursuing aerial insects in the manner of a flycatcher. They are 

 usually found in small flocks that move noisily through the woods, 

 traveling at all heights. Nothing seems to be recorded about the nesting 

 behavior of any species in Panama, although such research would prove 

 most rewarding. Not only are the varying degrees of nesting coopera- 



