330 Brewster, The Red-legged Black Duck. [^^^ 



among the total number on the ice — a surprishagly small propor- 

 tion of "adults" to "immature" birds if Dr. Dwight's opinions are 

 correct. All the birds satisfactorily seen had legs either bright red 

 — almost as deep and pure as that of red sealing wax — or dull 

 brownish, there being no indication of intergradation in this respect. 

 Four red-legged birds stood together in one place; in another there 

 were five with a single brown-legged bird; in still another four, 

 represented by two mated pairs separated by a space of only a few 

 yards. The remaining two were far removed from the others and 

 among brown-legged birds. Although most of these ducks were 

 unquestionably wild ones, about to migrate to breeding grounds 

 lying further north, a few may have strayed from some of the park 

 ponds in Boston or Brookline where miscellaneous collections of 

 semi-domesticated water-fowl are kept. I mention this slight 

 uncertainty partly to guard myself against the possible accusation 

 of inconsistency which might be suggested by a criticism that I 

 shall make presently of certain observations of park water-fowl 

 by Dr. Dwight. It can scarcely fail to be recognized, however, 

 that the two cases are not parallel, or to be admitted that even if a 

 few of the birds seen at Fresh Pond were not really wild, the fact 

 has little or no obvious bearing on the use I have made of the 

 evidence they furnished. Where I refer to "pairs" I mean that 

 each of these consisted of a drake and a duck, not of two birds 

 of unknown sex. It is perfectly easy — at least in spring — to 

 distinguish male from female Black Ducks when mated birds are 

 standing together on ice or land and not too far off; for the males 

 are decidedly larger than the females and also appreciably different 

 in form and carriage. 



Although Dr. Dwight is given to insisting that no one unprovided 

 "with full series of birds taken during the breeding season, in their 

 summer haunts, should presume to pass upon questions in w^hich the 

 value or significance of differences of color or markings is involved, 

 his paper on Black Ducks lacks satisfactory assurance that, with the 

 exception of a single specimen, any of the birds he mentions were 

 obtained in localities where they had certainly settled to breed. He 

 apparently admits, and at the same time defends, this violation of 

 his favorite rule by pointing out that "There are many difficulties 

 to be overcome in obtaining breeding specimens which of course 



