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1. From Palmer, R. S. 1976. Handbook of
North American Birds, Waterfowl, Vol. 3, pp. 164-165. "NOTES:
Females usually have some white feathers on the head, especially on
rear of crown and on upper nape (illustration in Weller 1957), the
number of these seemingly increasing with age but the most
conspicuous increase occurs during 2nd fall-winter. Nearly all wild
[females] have a few white feathers, captive [females] rarely. The
location of such feathers is an indication that they occur as a
result of damage to feather follicles when the drake pinches the
head of the [female] during copulation (Weller). A [female] in Feb.
had a white throat, ventral upper neck, patches on forehead and
lores, and also white feathers distributed sparsely on cheeks, nape,
and sides and back of neck." |
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2. From Weller, M. W. 1957. Wilson
Bulletin 69 (1): 4-38. Quote, page 25. "Adults...usually have white
feathers on the back of the head (Fig. 13). These white head
feathers are of particular interest; their numbers seem to increase
with age as in hawks (Brooks 1920), but the most conspicuous change
appears to occur during the second fall and winter. Nearly all wild
hens have a few white feathers, but captive females rarely do. The
location of these feathers suggests that they may develop as a
result of damage to the feather follicle when the male pinches the
female's head during copulation. However, attempts to induct
formation of white feathers in four females by pinching the skin
with pliers were unsuccessful. White feathers occur less frequently
and less abundantly in other members of the genus Aythya in North
American and in the European Pochard." |
