1873.] MR. H. E. DRESSER ON CERTAIN EAGLES. 515 



result of my investigations. The next question that arises is as to 

 whether Aquila orient alls and Aquila bifasciata are identical ; and 

 on this subject I beg to offer the following remarks. 



Taking the four specimens of Aquila bifasciata sent by Mr. 

 Brooks to illustrate the various plumages of that Eagle, my speci- 

 mens of Aquila orientalis exhibit a very close affinity to that bird. 

 My young example from Sarepta compared with No. 1, or the 

 youngest bird in Mr. Brooks's series, agrees precisely in coloration, 

 except that the Aq. orientalis is rather darker ; and on close examin- 

 ation I find that Mr. Brooks's specimen has the plumage somewhat 

 worn, whereas in mine the feathers appear to be quite freshly moulted, 

 which will easily account for the difference in colour. No. 2 in Mr. 

 Brooks's series has the underparts coloured as in the young Aq. orien- 

 talis above referred to, but has lost the bars on the wing and the yel- 

 lowish tip to the tail, the upper tail-coverts being white at the tip, 

 marbled with brown instead of yellowish buff as in the very young 

 bird ; some of the inner secondaries are much worn on the edge, 

 and it appears almost as if the yellowish-buff border had been worn 

 off ; on the nape are a few of the dirty yellow feathers of the fully 

 adult plumage. No. 3 in Mr. Brooks's series appears to me younger 

 than No. 2, and should come in the second place ; for it has still 

 remains of the first stage of plumage on the tail-coverts and secon- 

 daries ; otherwise it differs little from No. 2. 



The adult specimens of Aquila orientalis which are usually sent 

 with the eggs from the Volga correspond in plumage with Nos. 2 

 and 3 in Mr. Brooks's series, but have the head and nape of a pale 

 uniform brown colour, and not as in the adult Aq. bifasciata, which 

 is dark brown on the head and rufous yellow on the nape ; more- 

 over the adult bird from the Volga has the upper tail-coverts nearly 

 uniform brown, a few feathers only being dull white, marbled with 

 brown at the base. I am, however, indebted to my friend Captain 

 Elwes for the loan of a specimen from the Bosphorus, which in 

 plumage agrees very closely with No. 4, or the fully adult bird in 

 Mr. Brooks's series, which he also sends as agreeing with No. 934 of 

 Mr. Hodgson's illustrations. Like this bird, the Bosphorus speci- 

 men has the crown dark brown and the nape rusty yellow ; but it 

 differs from it in having the upper tail-coverts uniform dark brown, 

 whereas in the adult Aquila bifasciata they are yellowish wliite 

 barred and tipped with dark brown, reminding one somewhat of the 

 inner secondaries of the Short-eared Owl, except that the bars are 

 wider apart in this eagle's tail-coverts. 



This specimen from the Bosphorus, I should think, is the adult (or 

 rather a very old specimen) of Aqvila orientalis ; for it is the only one 

 that I have ever seen that has assumed this stage of plumage. Before, 

 however, the question can be set at rest, it will be necessary to collect 

 together a large number of specimens in all stages of plumage. This 

 I am now trying to do, and hope that I shall in the course of time 

 be able to lay before this Society the result of my investigations. 

 How soon this will be it is impossible to say ; for time must be put 

 out of the question by any one who takes up Raptores to work at. 



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