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Show 1873.] MR. H. E. DRESSER ON CERTAIN EAGLES. 515 result of my investigations. The next question that arises is as to whether Aquila orientalis 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, m y specimens of Aquila orientalis exhibit a very close affinity to that bird. M y 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 examination 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. orientalis above referred to, but has lost the bars on the wing and the yellowish 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 secondaries ; otherwise it differs little from No. 2. The adult specimens oi 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 ; moreover 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 m y 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 specimen 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 white 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 Aquila 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 m y 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. 33* |