FAMILY FALCONIDAE 283 



The close superficial resemblances of this species to the bat falcon 

 have led to some uncertainties as to its classification. The proportions 

 of the foot, where the middle toe with its claw is definitely longer than 

 the tarsus, place it near the duck hawk. The form of the tail also 

 agrees with that of Falco peregrinus as the central feathers are very 

 slightly longer than the outer ones so that the form is slightly tapered 

 when folded. However, the supposition that deiroleucus is merely 

 a tropical form of Falco peregrinus is not to be accepted. 



Coltart (Ool. Rec, vol. 26, 1951, p. 43) has described two nests, 

 one with 2 eggs and one with 3, from Trinidad, "collected by G. D. 

 Smooker on 21st April, 1930, and 28th March 1937. One nest was 

 30 feet up in a knot hole in a ceiba tree, whilst the other was in the 

 hollow at the base of a palm branch about 40 feet up. The eggs have 

 a whitish or yellowish ground, more or less obscured by smears and 

 blotches of browny-red and dark-red with a few darker superim- 

 posed blotches." They measure 43.0 X 35.0 ; 42.2 X 34.7, and 40.5 

 X 34.5 ; 41.7 X 35.3 ; 39.7 X 34.5 mm. 



FALCO RUFIGULARIS PETOENSIS Chubb: Bat Falcon; Halcon 

 Cazamurci^lagos 



Figure 49 



Falco rufigularis petoensis Chubb, Bull. Brit. Orn. Club, vol. 39, Nov. 30, 1918, 

 p. 22, (Peto, Yucatan.) 



A small, heavy-bodied falcon that in life appears black, with 

 white or buff throat, cinnamon abdomen and tibia, (some with a 

 cinnamon band on upper chest) ; breast and sides barred narrowly 

 with white and buffy white. 



Description. — Length, 230 to 270 mm. Adult (sexes alike), head, 

 including cheeks, and hindneck black; back, wing coverts, tertials, 

 rump, and upper tail coverts black basally, tipped and washed with 

 dark gray; primaries and secondaries black, the inner primaries and 

 secondaries in fresh plumage edged narrowly at the tip with white; 

 tail black, tipped narrowly with white ; throat and f oreneck white or 

 buff, often cinnamon-buff at sides and across chest ; breast and sides 

 black, barred narrowly with white to cinnamon-buff ; abdomen, tibia, 

 and under tail coverts dark cinnamon; under wing coverts black, 

 spotted and barred with white and buff; undersurface of primaries, 

 secondaries, and tail barred very narrowly with white. 



Immature, like adult but blacker above, and with under tail coverts 

 barred broadly with cinnamon-bufif. 



