Lack of association among duck broodmates during migration and wintering

Male (Lensink, 1964: 19) and female ducks tend to return to the area where they last bred or were raised (Sowles, 1955). Band recovery data show a similar tendency for ducks to return to wintering areas (Stewart et al., 1958; Martinson, 1966). Wintering British Columbia Mallard (Anas platyrhynchos) populations may be definite associations of birds that breed in the same general locality, migrate together, and use the same wintering area (Munro, 1943). On the other hand Gollop (1965: 36-37) showed that Mallards reared in Saskatchewan or breeding there re- turned in subsequent years, but "neither migrated nor wintered as definite associations." He based his conclusions on recovery data from groups of Mallards banded on the same slough and from broodmates. His data showed, by date or area of recovery, that the birds migrated independently and sometimes to different wintering localities. This paper presents additional data suggesting that ducks banded as brood- mates may migrate independently.