23 [Vol. xxiii. 



eclipse-plumage in a species of duck in which the sexes were 

 practically alike, and the first notice of an eclipse-plumage in 

 the female of any species of Duck. 



Mr. BoNHOTE also remarked that he had been making 

 some observations on the female Wigeon, although he was 

 unable to exhibit specimens on the present occasion. 



At the beginning of September obviously new or newly- 

 growing feathers on the breast and mantle of a female 

 Wigeon were marked in a manner similar to those of the 

 Sheld-duck. On examining the bird again on the 19th of 

 October it was found to be in a beautifully fresh-moulted 

 condition with many feathers still in the quill, and a most 

 careful and exhaustive search failed to show any of the 

 marked feathers, thus proving conclusively the presence of a 

 double autumnal moult in the female of this species. 



The difference in the two plumages was quite evident to 

 anyone thoroughly acquainted with the species, aud it was 

 the different appearance of the bird that led to its being 

 more closely examined ; roughly speaking, however, the two 

 plumages were very similar, but the eclipse-plumage was 

 rather darker and more rufous, especially on the flanks. As 

 was already known, the female Tufted Duck showed a special 

 plumage in which the feathers round the base of the bill 

 became white as in the Scaup, and it seemed probable to him 

 that further close and careful observations would show that 

 the females of most species of Duck had a double autumnal 

 moult and eclipse-plumage, thus showing that the latter 

 was not a plumage assumed by the drakes alone for the 

 sake of protection during the period when they were unable 

 to fly, and confined to the drakes of those species in which 

 the sexes were different, but that it was originally due 

 to other and more deep-seated causes embracing both sexes 

 and many species. Personally, as had been pointed out 

 by Mr. Lydekker and himself in ' The Field ' some years 

 ago "*", Mr. Bonhote believed that the eclipse-plumage really 



* 'Field,' Dec. 2nd <fc 16th, 1905, and March 24th, 190G. 



