Hunting mortality of mallards Anas platyrhynchos in relation to time of day, flocking behaviour, and individual condition

Diurnal variation in the number of mallards Anas platyrhynchos shot by hunters at Long Point, Ontario, was assessed during the 1989 hunting season to determine peak periods of harvest and to test the prediction that ducks shot during non‐peak periods would be in poor relative condition. In addition, attempts were made to determine whether lone mallards are disproportionately vulnerable to hunting and whether ducks shot as singles are in poor condition relative to those shot from flocks. Diurnal variation in size of the harvest was pronounced, with peak harvest occurring during the first third of the day. Relatively few ducks were shot at mid‐day, suggesting that mallards were largely inactive at this time. Analysis of abdominal fat masses, however, revealed no relationship between individual condition and time shot. Single mallards were apparently more vulnerable to hunting than were those occurring in flocks, as the hunter‐shot sample contained a high proportion of lone birds relative to an expected frequency based on observational data. However, no evidence of a relationship between individual condition and status (i.e. alone vs. in a flock) at the time of harvest was found. Our results, in conjunction with previous work, suggest that flocking behaviour may be a general component of hunting mortality in waterfowl and furthermore that increased vulnerability of lone birds can occur independently of variation in individual condition.