Reduction in owned cats outdoors in Canada and the US and animal welfare (Rethink Priorities)

Summary

1. Previously published estimates of the number of birds and mammals killed by owned cats are probably too large by over one billion animals. We estimated a median of 640 million animals killed in both the US and Canada, whereas it has been suggested that a median of 1933 million animals are killed in the US alone.
2. Our estimates suggest that interventions aimed at reducing owned cat predation will therefore directly affect a smaller number of wild animals (~830 animals per $1000) than previously suggested (~5500 animals per $1000)
3. A single-message advocacy intervention, such as promoting collars with predation deterrents (e.g. bells, bright colors) on all adopted cats, could have multiple benefits for the welfare of both owned cats and wild animals
4. However, cat predation may be a net benefit for wild animal welfare given the probability that this mortality is often compensatory, the large reproductive capacity of small rodents, and the inhumane methods of rodent control currently in use
5. The widespread use of rodenticides emerges from this analysis a wild animal welfare issue in need of further research with respect to the numbers of target and nontarget animals negatively impacted