on the Birds of Turkey. 67 



The male bird takes his turn at incubation, while the female 

 goes in search of food ; and they sometimes leave the nest entirely 

 for some time. The young are hatched at the end of April or 

 beginning of May, and do not remain in the country very long, 

 as we never observed an Imperial Eagle in immature plumage 

 during the whole of our journey. 



In the evening these Eagles roost with Kites and Falcons in 

 clumps of trees in the open country ; and by waiting at these 

 places just before dark we could always obtain specimens, as 

 there were often six or seven in one tree. In the Dobrudscha it 

 was by no means easy to distinguish this Eagle from the dark 

 form of the Tawny Eagle [A. navioides) which is found there ; 

 and the eggs vary so much in size that in some instances they 

 might easily be mistaken for those of the latter. 



7. Aquila navioides, Cuv. Tawny Eagle. 



Our attention was first called to this bird by M. Alleon, who 

 possessed in his collection a large number of specimens killed 

 by him during the passage, at Buyakdere, on the Bosphorus. 

 In the 'Revue de Zoologie' for 1866 (pp. 273-277, pi. 20) will 

 be found an illustrated article by him on this Eagle, which 

 he then supposed to be the A. moffilnik of S. G. Gmelin. Fur- 

 ther on in the same volume (pp. 356-359) M. Jules Vian, wri- 

 ting on the same subject, attempts to show that M. Alleon^s 

 Eagle is the A. clanga of Fallas, but gives it as his opinion 

 that A. clanga is not a good species and must be regarded as 

 a local form of A. navioides : in the same periodical for the 

 following year, 1867 (pp. 129-137), will be found an excellent 

 paper by him on this subject. M. Alleon's kindness has 

 enabled us to submit two specimens of this bird to Mr. 

 Gurney, who was at first of opinion that they must be referred 

 to some unnamed species, as he had never seen any like them 

 before ; but after going most carefully into the subject, and com- 

 paring the skins with an African specimen of A. ncevioides and 

 an Indian one of A. falvescens, he wrote as follows : — 



" Notwithstanding the remarkable diflPerence of coloration in 

 each of the three specimens, they agree so closely in other re- 

 spects that (greatly against my preconceived opinion) I am now 



f2 



