82



Mr. Frank Finn



SOME SPONTANEOUS VARIATIONS IN

MALLARD & MUSCOVY DUCKS.


Anas boscas and Gairina moschata.


By Frank Finn, B.A., F.Z.S.


Although both of them are ancestors of mere poultry-birds,

the Mallard of our common domestic ducks, and the Muscovy of

those kept over a large part of the Tropics, especially in Tropical

Africa and America, they may perhaps be allowed to form the

subject of the present article, inasmuch as the Mallards dealt with

are those kept as more or less ornamental birds, and the Muscovy

is in Europe and India, and probably elsewhere, chiefly kept as a

curiosity, and not for poultry purposes as in many hot countries.


In looking over the mallards kept in our London parks, it will

he noticed that many of the drakes vary from the typical form with

white collar, chocolate breast, and grey flanks, in two directions—in

one case the white collar remains, but the reddish-brown of the

breast is continued along the flanks and sometimes on to the

shoulders, while the upper parts are of a paler grey, often nearly

white ; in the other the white collar disappears, and the pencilled-

grey of the flanks invades the breast, to the complete exclusion of

the chocolate tint, reaching up to the green of the neck.


Both varietal forms are usually definite, but there is a little

inter-gradation with the type ; the chocolate may extend only a

little beyond the breast, or conversely may appear at the base of the

neck in an otherwise grey-breasted bird.


M. G. Bogeron, in his most excellent work “ Les Canards,”

p. 140, has cited a case which shows that there is a definite form of

female correlated with the grey-breasted drake ; he having hatched,

from mallard ducks of a wild origin, some black ducklings —

regular little niggers “vrais petits negrillons,” he calls them—

lie expected to rear from them a black variety, but found that when

they came into full feather, the drakes were of the grey-breasted

form above noted, while the ducks differed from the normal mottled-

brown type in having the head uniformly speckled, without the

light eyebrows and cheek-stripes to be seen in the normal mallard

female. The speculum or wing-bar in both sexes of this variety was



