Correspondence. 283


duller plumage than their mates, perform the duties of incubation. The

same uncertainty prevails in the case of the Brush-Turkeys and Megapodes ;

while the author cannot do more than suggest that the South American

Guans and Curassows are probably a monogamous group, as the two sexes

are nearly alike. The general rule among game birds appears, indeed, to be

that when the cock is conspicuously larger and more brilliantly coloured

than his mate, the species is polygamous, and vice versa. It is, however,,

not known with certainty whether the Argus Pheasant is a polyganiist,

although it probably comes under the same category as other Pheasants,,

all of which have large harems. With the monogamists are included

Partridges, most Grouse, and all Ptarmigan, but Sagecock, Capercaillie, and

Blackcock, together with Quail, are as markedly polygamous. Although

Peacocks retain their polygamous nature under all circumstances, domesti-

cation in certain instances causes some strange changes in the breeding

habits of game birds. Guineafowls, for example, are normally monogamists,

but in confinement a cock has been known to take charge of some half-

dozen hens, and these, too, without interfering with the number of eggs

normally laid by the latter. This last instance indicates the necessity of

caution on the part of observers who may endeavour to supply the gaps in

our knowledge indicated by Dr. Shufeldt from birds kept in a state of


captivity."


From The Field, May nth, 1907.


"Sir, — In The Field of May 4th appears a communication under this

heading, in which an article by Dr. Shufeldt in the American Naturalist

is quoted. It appears to me that main' of the conclusions arrived at are

very far from correct. In the first place we are told that "it is well known

that both the Ostrich and the South American Rhea are polygamous."

There appears to be little doubt, however, that the Ostrich is strictly mono-

gamous in a wild state, and success in breeding from tame birds can only be

assured by carefully pairing off the birds, or allowing them to pair off

naturally. Hunters tell of the finding of Ostrichs' nests owned by a single

pair of birds, no others being within several miles ; and in an account of

Ostrich farming in South Africa which appeared in the Ibis for January,

1906, the author clearly proves that these birds are not polygamous, and will

only breed successfully in pairs.


" Now for the Rhea. It is well known that in these birds the male


performs the duty of incubation, and it would seem to be almost an


impossibility for a species in which this is the rule to be polygamous. It


would be quite impossible for a single male to incubate all the eggs laid by


all the hens of a harem, and the waste of eggs would be enormous. There


is very little doubt, I think, that Rheas are polyandrous, and that those


observers who have credited the species with polygamy have mistaken the


sexes.


"The case of the Guinea-fowl, a naturally monogamous species^,


becoming polygamous in captivity is quoted as an instance showing the



