IIO Barrows on Birds of the. Loxver UrugJtay. [April 



shot, but an examination showed that though its crop was 

 crowded to its utmost capacity, it contained nothing but young 

 grasshoppers, not a trace of other food being found in its stomach. 



133. Geranoaetus melanoleucus {VieilL). Aguila 

 (Eagle). — An abundant resident at all points visited, and not 

 at all difficult of approach. In ascending the Uruguay by 

 steamer it is one of the most constant features of the landscape, 

 sometimes seen sailing in circles overhead, but oftenest sitting 

 motionless on the highest branch of some dead tree which rises 

 from the tangled masses of lower growth on the low islands 

 along the swampy shores. On the Pampas it was frequently ob- 

 served, and on the Ventana, where it was abundant and doubt- 

 less nested, it was ridiculously familiar. 



While hunting Parti'idges one morning, I walked directly up 

 to one of thess Eiigles, as he sat on a stone gazing at me, 

 and when, finall}', at a distance of eight or ten yards, he 

 started to fly, a charge of No. 8 shot was sufficient to stop him. 

 The same morning another was killed in almost the same way 

 with No. 6 shot. On March 8, while near the Ventana, a pair 

 was seen in a plumage entirely new to me. Seen from below they 

 were entirely glossy black, with tiie exception of ''he tips of the 

 tail-feathers and primaries, which were pure white. If this is the 

 normal adult plumage it must be rare, at least about Concepcion, 

 as I never met with an example of it among over a hundred speci- 

 mens observed there. Of the nesting habits I learned nothing, 

 except that on the Ventana a pair constantly resorted to an inac- 

 cessible ledge near the summit, where I believe they must have had 

 a nest. Doring says they nest abundantly on the ground along the 

 Rio Negro of Patagonia, placing the nest usualh-, however, on 

 some small eminence along the bank of the river. 



134. Accipter sp. incog. A female of a species allied to A. 

 fusciis was taken at Concepcion, July 14, 1880, and another 



individual (possibly the mate) was seen very near the same spot 

 a few days later. 



135. Falco sparverius Linn. Alconcito (Little Fal- 

 con). — A very abundant bird at Concepcion, where a few are 

 resident and doubtless breed, but especially plentiful in spring and 

 autumn. I did not see its nest. 



A young female taken January 21, 1880, was peculiar in hav- 

 ing the ovaries oi both sides equally developed, though both were 

 small. 



