646 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



streaked like the throat ; the rest of the breast streaked and spotted with 

 arrow-shaped marks of deep seal-brown ; abdomen not so definitely 

 marked with brown, which here is shaded with rufous ; the thighs and 

 under tail-coverts deep buff, inclining to rusty, and marked with tri- 

 angular-shaped barring of rusty brown,, bright in tone. 



"Bill horn-blue; iris dark brown ; feet and legs yellowish-green" (J. B. 

 Hatcher). 



Dark phase. — Male. No. 7865 P. U. O. C. Pacific Slope, Cordilleras 

 of Patagonia, 16 March, 1897. J- B. Hatcher. 



The prevailing color throughout on the body is chocolate or deep seal- 

 brown ; this is shaded on the back with tawny, on the wings, which are 

 barred on all the coverts and quills obsoletely with deeper shades, with 

 slate-grey, hoary in character ; there is also some rufescent shading on the 

 very dark, immaculate under surface ; the tail is slate-grey from above and 

 pale silvery grey from below, crossed by sixteen or more narrow wavering 

 bars of deep brown ; the tail is broadly tipped with pale slate frosted with 

 white. "Eye light brown; bill blue horn-color; feet and legs yellow" 

 (J. B. Hatcher). Length 20.00; wing 14.90. 



Geographical Range. — From just south of Buenos Aires throughout 

 Patagonia, northern Tierra del Fuego and the Falkland Islands ; the 

 Straits of Magellan and north on the Pacific Coast into Peru. 



This hawk appears to be resident where it occurs and to be one of the 

 conspicuous elements in the bird fauna of Patagonia. It breeds in 

 October and November, and as its range is extended by our present 

 knowledge into the forests of the Cordilleras as well as on the more open 

 pampas and plains, to very high altitudes, we may conclude that the time 

 of breeding varies considerably with the range. The birds nest in trees 

 and low bushes as well as upon cliffs, but it seems improbable that they 

 nest at any point in "long grass" upon the ground, as suggested by Mr. 

 Holland, in notes appended. Birds of this genus, notably Bitteo borealis, 

 we are well aware, adapt themselves to local conditions so as to depart 

 from inaccessible nests in high trees, to nests in bushes or low trees so 

 near the level of the ground as to be easily examined without even 

 climbing, the investigator being well able to see all that is inside the 

 structure, while standing on the ground. But, so far as we have data 

 we are unable to get records of the nest of any kind of Buteo directly on 

 the ground. 



