208 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



ary, and at 2,100 meters elevation above Cerro Punta. Wedel shot 

 one near Changuinola, Bocas del Toro, December 9, 1928 (Peters, 

 Bull. Mus. Comp. Zool., vol. 71, 1931, p. 310). 



Usually they are seen soaring high in air, turning in circles, and 

 occasionally uttering a shrill, screaming call. As they tilt a bit in the 

 air currents a view of the bright brown color of the tail makes their 

 identification certain. 



The nesting of this subspecies has not been recorded. 



BUTEO JAMAICENSIS CALURUS Cassin 



Buteo calurus Cassin, Proc. Acad. Nat. Sci. Philadelphia, vol. 7, no. 7, Jan.-Feb. 

 (May 22), 1855, p. 281. (Fort Webster, Rio Mimbres, New Mexico.) 



Adult, in normal phase, like B. j. co stark ensis, but blacker above ; 

 below washed with pale buflf to pale cinnamon ; tibia barred definitely 

 with bright brown. In melanistic phase, the bird is blackish brown 

 above and below, with the under tail coverts marked with cinnamon ; 

 wings white to gray underneath. Some in the dark phase have the 

 head, hindneck, and upper back edged with cinnamon. 



On the whole they are like the resident subspecies, but in nor- 

 mal dress are darker, and much darker in the black phase. 



Casual wanderer from farther north. One record, a bird in the 

 British Museum, shot by E. Arce in 1870 on the southern slopes 

 of Volcan de Chiriqui. 



This darker race of the species nests from Alaska and northern 

 Canada south through the western United States to Baja California 

 and New Mexico. In winter some wander south to Guatemala, cas- 

 ually as far as Nicaragua. 



BUTEO SWAINSONI Bonaparte: Swainson's Hawk; Irol 



Buteo Swainsoni Bonaparte, Geogr. and Comp. List, 1838, p. 3. (Fort Vancouver, 

 Washington.) 



A large hawk, variable in color, similar in form to the red-tail, but 

 with three outer primaries incised at the tip. 



Description. — Length 450 to 550 mm. Adult, pale phase, upper 

 surface dark grayish brown to fuscous, the feathers with narrow 

 edgings of grayish white to cinnamon ; forehead and lores white, the 

 former streaked with grayish brown ; feathers of nape with concealed 

 white bases; lateral upper tail coverts white to tawny, barred with 

 grayish brown ; secondaries fuscous, tipped lightly with white to 

 cinnamon; primaries dull black, with outer webs toward tips more 

 or less grayish; rectrices brov\Tiish mouse gray, tipped with grayish 



