Climate change increases the distribution of reservoirs of the Raccoon Rabies Virus in Quebec

Ariane Bussières-Fournel, Timothée Poisot 

Zoonoses often emerge in environments where human-animal interactions intensify. In Québec, climate change and land use alterations are suspected drivers in the shifts of the potential distribution of urban-adapted hosts such as raccoons (Procyon lotor) and striped skunks (Mephitis mephitis), which serve as reservoirs for Raccoon Rabies Virus (RRV; a variant of Lyssavirus rabies). We used species distribution modeling (SDM) to predict current and project future potential habitats for P. lotor and M. mephitis under three climate change scenarios (SSP126, SSP370, SSP585) from 2021 to 2100. Our model predicts significant northward expansions of potential habitats for both species, with P. lotor exhibiting faster and broader shifts compared to M. mephitis. High-emission scenarios further amplify these shifts, proportionally favoring the apparition of favorable habitats for P. lotor. Potential habitats for these reservoirs are projected to overlap with areas that currently lack robust infrastructure for surveillance and vaccination, highlighting potential public health vulnerabilities. Using a technique from interpretable machine learning, we provide a more mechanistic understanding of why the response of both reservoirs to climate change is decoupled. This study underscores the need for proactive monitoring of ecological and epidemiological shifts in Quebec as climate change alters the potential distribution of key wildlife reservoirs.