144 THE BIEDS OF MONGOLIA ETC. 



6. Aquila imperialis, Bechst. Orel Mogilnic. 



We shot a single specimen at Koko-nor, Avhich appears to be a ^^ouno- 

 bird and exactly corresponds with the one figured in Gray's 111. Ind. Zool. 

 ii. pi. ^xviii., only that the lines of the wings are of a deeper yellow colour 

 than in the above-mentioned plate. 



This species was observed in Mongolia by Pere David ; and at Koko-nor 

 we found it wintering. We did not see there any old birds with white 

 shoulders. The present species is altogether scarcer in S.E. Mongolia and 

 Koko-nor than the succeeding allied one. 



7. Aquila bifasciata. Gray. 



Has been found all over the country traversed by us, but is commonest 

 in S.E. Mongolia and Koko-nor. In the former locality the Eagles find 

 suitable breeding-places in the mountains forming the boundary between 

 Mongolia and China; whilst the neighbouring steppes, inhabited by the 

 Lagomys in great numbers, afford sufficient food for them. On the Koko-nor, 

 where these mammals are also abundant and where there is but little snow 

 in the cold season, many birds of prey are induced to winter ; and not being 

 pursued by man, they get tame very soon. 



The cleverness with which Aquila lifasciata catches the Alpine hare is 

 something extraordinary. The poor beast, which sits close to its hole, has 

 not time to jump in before it is seen in the claws of the rising Eagle which 

 has just swooped down upon it. These Eagles also prey upon Ptarmigan 

 (Ferdix harbatd) ; and on one occasion we took from a young male specimen 

 in Kan-su an Eagle Owl (^Bubo mawimus), which it was carrying in its talons. 

 Evidently hunger had compelled the Eagle to attack such dangerous and 

 uninviting game« 



Pairing commences in March ; and at this time we could often see 

 the male bird chasing the female high up in the air, uttering at intervals a 

 tolerably loud cry, somewhat resembling the barking of a dog. The nest is 



