Is there a spatial match between roadkill and mitigation measures identified by functional connectivity modeling?
Résumé
Linear transportation infrastructure affects the ability of wildlife species to live and move through anthropized landscapes. Mitigation measures are thus needed to maintain population viability. Several methods have been employed to determine optimal locations for these measures, including connectivity modeling, which targets areas with the strongest connectivity and/or potential connectivity gains. However, these results are seldom compared to biological data, such as roadkill. The objective of our study is to: i) to gain a deeper understanding of the relationships between roadkill and connectivity, ii) to spatially identify road sections with a high risk of roadkill and, iii) to compare high-risk roadkill areas with the locations identified for potential mitigation measures. We performed a generalized linear model to explain occurrence and abundance of roadkill and predict high-risk roadkill areas. The mitigation measures corresponded to either i) existing crossing structures that could be enhanced to facilitate wildlife passage, selected from the initial connectivity or ii) new wildlife crossings designed to reconnect habitats identified through connectivity gains.
Our results indicate that connectivity significantly influences the occurrence and abundance of roadkill. However, the high-risk roadkill areas only partially align with the locations designated for mitigation measures. Since some roadkill occurs outside of high-connectivity areas, factors other than connectivity must also be taken into consideration. This study offers valuable insights and underscores the complexity of the relationships between connectivity, roadkill, and mitigation efforts. Furthermore, by integrating spatial modeling, mitigation strategies, and roadkill data, this study contributes to a deeper understanding of corridor restoration areas and their importance in species conservation.