Team Chiro

The world's road networks cover over 21 million kilometers, and experts predict that this total will increase by about 25% by 2050. However, these transportation infrastructures have been recognized as one of the top ten causes of biodiversity loss. The direct impact on biodiversity is significant, with roads causing increased mortality due to collisions, destruction of habitats, and transformation of landscapes. The indirect impact is also substantial, as roads can fragment habitats and create barriers to the movement of individuals for most terrestrial species, including bats. These barriers are caused by the disruption of ecological continuity, collisions with vehicles, the structure of the road, and road-avoidance behavior linked to the loss of habitat attractiveness probably due to chemical, noise, and light pollution generated by traffic. These barrier effects impact the functional connectivity of habitats and can have demographic and genetic consequences for populations.

 

The ecological effects of roads the ecological effects of roads are detectable within an area known as the road-effect zone, which can extend to at least 5 km for the most sensitive bat species. Although there is considerable evidence of largely negative impacts of roads on bats, positive effects have been also observed. Roadsides can include grass strips and hedgerows that provide food resources for bats. Additionally, roadside hedgerows can help decrease noise and light pollution, which can reduce bat avoidance, and also provide flight corridors for bats. Despite the potential sensitivity of insectivorous bats to road pressure, the impact of roads on bats and the effectiveness of the mitigation hierarchy in addressing road-related impacts remain inadequately documented and require further investigation for a better understanding.

 

Within the CESCO, we study the road-related impacts on bat populations at various spatiotemporal scales:

• At the landscape scale and over long time intervals (population survival...);

• At the landscape scale and over a year (barrier effect...);

• At the road level and on a daily basis (disruption of connectivity...).