Rats! What triggers us to control for rodents? Rodenticide user survey in British Columbia, Canada

Abstract

Anticoagulant rodenticides (ARs) are used worldwide to suppress rodent populations. Owing to the highly toxic and persistent properties of ARs, farmland predators are increasingly being documented with residues in their systems. Our objective was to evaluate the usage of ARs in Delta, the main region where raptor carcasses have been collected for AR residue testing in British Columbia. We found that farmers most frequently engaged in rodent control (95%). Hobby farmers and residential owners only engaged in rodent control if rodents had been seen or had damaged their property. Products containing brodifacoum were most frequently applied (32%), which was also the most commonly found AR in raptors sampled in the region. Unintended misuse (17%) stemmed from a lack of understanding about the differences in toxicity of products. Our survey demonstrates the need for more information for land-owners regarding correct AR application and safe disposal of poisoned rodents.