Animal community structure and dynamics under cumulative impacts of roads

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Environmental conditions can influence life history traits such as body condition, probability of survival, and reproductive output. For instance, energetic costs resulting from variable environmental conditions such as harsh winter conditions or low habitat quality may force individuals to defer migrations or reproduction to a subsequent year and devote resources to growth instead. The expansion of road networks and the effects of these infrastructures on animal and plant populations have received attention worldwide. Several investigators report high animal mortality rates on roads, but the relationship between these ad hoc mortality rates and actual demographic parameters remains unknown. In this research program, I will quantify the cumulative impacts of roads on breeding phenology, population and community structure, and trade-offs between the energy expended for growth or reproduction, through replicated mark-recapture studies and field experiments. ******My short-term objectives are 1) To quantify the impact of road construction on breeding phenology, survival, and reproductive success, 2) To assess the influence of roads on community dynamics and interspecific interactions, and 3) To quantify the impact of roads on the population structure of long-lived species. My research program will feature amphibians and freshwater turtles as model organisms. The work will be conducted in two study areas. The first study area will consist of a before-after control-impact design in southern Québec, where we will excavate ponds near highways recently constructed but not yet open to trafic, but also in areas projected for road construction. The second study area will take advantage of a network of 108 roadside ponds monitored since 2012 in two regions separated by 600 km along a north-west gradient in western Québec. ******We predict 1) a marked decrease in survival probability, breeding probability, and reproductive output at sites after road construction and opening to vehicular trafic (i.e., time x treatment interaction), 2) that amphibian communities are more dynamic (greater colonization probability) at northern latitudes relative to southern latitudes, and that the proximity and type of road exacerbates these changes (distance x road type interaction), 3) that turtle abundance, recruitment, and nest survival are lowest in ponds closest to highways (road type x distance to road interaction).***Beyond the effects of roads on life history strategies, this work will allow to distinguish between the effects of road construction (habitat loss) and trafic intensity (road mortality). My research program will inform spatially-explicit individual-based models to estimate population persistence in the context of road construction. My research program will provide valuable tools to manage wildlife populations near roads and inform new road construction projects in Canada and abroad. **