The effect of a ban on the use of lead ammunition for waterfowl hunting on duck and goose crippling rates in Illinois

Globally, there is increasing effort to transition away from the use of lead ammunition to mitigate its known risks to wildlife and human health. Whenever this transition is stated hunters frequently cite concerns about the effectiveness of non-lead ammunition, how it will result in greater crippling rates, and associated animal welfare costs. This area has been little studied, but recent studies have found no differences in crippling rates using lead and steel ammunition. Using segmented linear regression we evaluated 37 years of waterfowl harvest data in Illinois, United States, overlapping the transition to non-lead shot for waterfowl hunting in order to assess how crippling rates changed following the ban. The average crippling rate prior to the lead shot ban was 23% for both ducks and geese and reduced to an average of 15% and 11% for ducks and geese (respectively) following the ban. In addition, the annual trend in the proportion of ducks and geese crippled reversed following the ban, from a significant annually increasing to a significant annually decreasing trend. We offer hypotheses on behavioural and technological changes which may explain these changes and predict that crippling losses will not increase in Europe following a ban on the use of lead ammunition over wetlands in 2023.