106



Mr. Frank Finn



tells me that he has two males now in a cold outdoor aviary doing

well and, which is still more notable, in full summer plumage, though

lie thinks that they moulted at the usual time.



SOME SPONTANEOUS VARIATIONS IN

MALLARD & MUSCOVY DUCKS.


Anas boscas and Cairrna, moschata.


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


{Concluded from page 88).


I ought to have mentioned above that the second lot of

ducklings from the two domesticated Muscovys alluded to on p. 86

as black with yellow neck-patches in the down, have fledged off

exactly as their predecessors with the same down-colour and parent¬

age had done, with brown tippings to the feathers of face and under¬

parts ; some of these also had the white neck-spot like the mother,

hut not all. As I did not pay attention to the inheritance of this

point, I cannot give the number of those which showed it.


To return to the question of the significance of these duck-

variations; another point they throw light upon is the origin of more

striking colouring in a species. When such a point distinguishes

both sexes from the young, it is commonly presumed that the male

has acquired it first and that then it has been transferred to the

female ; in the Muscovy duck we can see that both processes are at

work, without human or natural selection.


The hare face has indeed been generally transferred to the

female in domestication, in whatever part of the world she is kept ;

at any rate, I have seen it in specimens bred in India, Africa, America

and Europe.


On the other hand, the white head, which is often the only

abnormal part of the plumage, and looks just as natural as the

white head of the Bald Eagle (. Haliaetus leucocephalus) appears in¬

differently in both sexes. As it does not appear in the immature

plumage, anyone not knowing the true wild Muscovy duck would, I

am sure, conclude that this is simply the proper adult colouring of

the species in default of evidence to the contrary.



