ASSUMPTION BY FEMALE BIRDS OF MALE PLUMAGE. 15 



found in an appendix to Mr. Cambridge's paper (Proc. Dorset 

 Nat. Hist. Club, vol. vii. p. 91), where Mr. William Pennay, of 

 Poole, is stated to have found near that place two specimens of a 

 black variety. 



ON THE PARTIAL ASSUMPTION BY FEMALE BIRDS 

 OF MALE PLUMAGE. 



By J. H. Gurney, F.L.S., F.Z.S. 



This is an interesting subject, and one which has engaged 

 the attention of such naturalists as John Hunter, Darwin, and 

 Yarrell, whose paper read before the Royal Society is classical.* 

 In the last number of * The Zoologist' (1893, p.458), Mr. Coburn 

 has referred to the case of a female Merganser, Mergus serrator, 

 assuming male plumage. A similar case came under the notice 

 of my late father. He proved by dissection that a supposed 

 young male Merganser, showing a considerable amount of black 

 plumage about the head and neck, was a female. Sueh cases as 

 these indicate that the change is not a result of semi-domestica- 

 tion, although the likelihood of the metamorphosis is increased 

 by domestication, as demonstrated in the cases of the hen, duck, 

 and pheasant. 



It would be interesting to ascertain what species among the 

 Anatidce have exhibited this abnormal tendency. Four may be 

 named: — the Mallard, Anas boschas, the Wigeon, A. penelope, 

 the Tufted Duck, Fuligula cristata, and the Scaup, F. marila. 

 The Rev. H. A. Macpherson, in his 'Study of British Birds* 

 (pp. 71, 72), is my authority for the Tufted Duck, and the late 

 Edward Blyth for the Scaup. The normal adult plumage of a 

 female Scaup is a white face and brown head and neck turning 

 sooty black (A. C. Chapman, Zool. 1887, p. 8). The female bird 

 figured in Dresser's * Birds of Europe' is not adult. 



The late Mr. Cecil Smith remarked this masculine change 

 in a female Wigeon ('Ibis,' 1888, p. 228), and it has been noted 

 not unfrequently in the ordinary Wild Duck, A. boschas, in 

 England, with one exception (Birds of Northumb. and Durh., 



; * Phil. Trans. 1827, p. 268—275. See also a paper by -him on the 

 assumption of the male plumage by the female of the common Game -fowl, 

 Proc. Zool. Soc. 1831, p. 22. 



