Using spatial parameters to assess pesticides as a plausible threat to fauna

The impact of pesticides on fauna remains a little-known topic. In Europe and North America, the belief that insecticide use may be partially linked to populational declines in pollinating insects is one based on fragments of evidence. Classifying pesticides as a biodiversity threat might therefore be more reliant on the perceived interactions between species and sprayed crops. Brazil’s high pesticide use and rich biodiversity provide an opportunity to assess whether spatial parameters can be used to infer the potential biodiversity threat of pesticides by mapping the risk of exposure faced by 100 animal species considered threatened by these chemical agents. A given specie’s risk of exposure is the proportion of its potential distribution that overlaps with agricultural areas utilizing pesticides relative to the area of remnant natural vegetation. When these parameters were applied, results show that only 16 % of those species in Brazil considered threatened by pesticides had a high risk of exposure. This article argues that citing pesticides as a specie’s threat based only on assumptions confuses the understanding of a link that is already difficult to verify. Spatial parameters such as risk of exposure offer a more objective approach to assess the threat plausibility pesticides pose to fauna and can reveal other overlooked species possessing higher potential from being impacted by these chemical agents.