An Unusually Early Molt in the Ruddy Duck
An Unusually Early Molt in the Ruddy Duck
Although it is not unusual to see Ruddy Ducks (Oxyura jamaicensis rubida) in partial nuptial plumage by early March, Phillips (Nat. Hit. Ducks, vol. 4, 1926, p. 161) gives March 18 as the earliest known date at which this plumage has been found complete. It was therefore a matter of considerable surprise when, in the late afternoon of January 3, 1938, a male of this species was seen in the western part of Stow Lake, Golden Gate Park, San Francisco, in complete breeding plumage.
This individual was no more than twenty-five yards from shore when seen, and it afforded ample opportunity for close scrutiny. The unworn and unfaded appearance of the feathers precluded the possibility that this might be an old male that had failed to molt its nuptial plumage the previous autumn.
This same individual was observed at this locality on ensuing days and on January 7 a careful check was made of all the Ruddy Ducks on the lake. On this day about 75 individuals of this species were seen, of which approximately one-half were males. A careful examination of each bird through field glasses showed only one additional male to be in other than full eclipse plumage which is normally retained during the autumn, winter and early spring until late March or April. This bird had black on the head but not as yet on the nape. A considerable spotting of chestnut was present on the mantle, scapulars and sides.
Robert T. Orr
California Academy of Sciences, San Francisco, January 11, 1938
