title: Road impacts on tropical wildlife: predicting risks for different areas and species
Creators: name: Medrano Vizcaino, Pablo Mauricio
Publisher: name: University of Reading
Year: 2023

description: Social and economic development are often accompanied by expansion in infrastructure
including roads. The presence of roads is prevalent globally with general plans for expansion
particularly in megadiverse areas such as Latin America. Given the growing road network
and the extraordinary biodiversity in this region, many species could be impacted by
mortality due to vehicle collisions. Nevertheless, deficient road ecology research has resulted
in limited knowledge of these impacts, which also hinders the development of conservation
and mitigation strategies. For this thesis, I bring together different approaches at different
spatial scales to evaluate roadkill impacts on Latin American and Caribbean wildlife. In the
first chapter of this thesis, I present the close relation that humans have had with roads since
ancient times, and how the increasing mortality of species on roads has called the attention of
researchers since early 1920’s until current times, leading to the development of sophisticated
methods for data analysis and new mitigation measures. For the second chapter, I developed
predictive traits-based models for Latin American and Caribbean birds and mammals, which
revealed a higher mortality for larger birds and medium-sized mammals with early maturity
ages, more clutches/litters per year, higher population densities, and diet and habitat
generalist habits. Spatial predictions revealed that roads across Central America, northern
Andean regions, eastern Brazil, Uruguay, central-eastern Argentina, and southern Chile
harbor higher mortality. For the third chapter, using predicted roadkill rates for birds and
mammals from chapter 2, information on road network, species conservation status, and
availability of road ecology studies, I identified priority areas and species for research and
conservation in road ecology in Latin America and the Caribbean. For the fourth chapter, I
analysed the spatial distribution of 1,125 roadkill records (that I collected across 240 km of
roads in the Ecuadorian Amazon) in relation to landscape and road-related features. Results
showed that wildlife mortality is more likely in straight sections of roads near rivers, and that
for birds and mammals, proximity to forests and herbaceous-shrubby vegetation can also
increase mortality. I also identified taxa-specific roadkill hotspots across the study area. For
the fifth chapter, I conducted an assessment of wildlife road mortality at country level in
Ecuador presenting a citizen science project I founded. For the assessment I compiled 5,010
roadkill records from systematic and non-systematic surveys, and identified the species and
areas for which, further research and conservation actions are necessary. The final chapter
presents a general discussion. Overall, this thesis constitutes a comprehensive evaluation of
the impacts of roadkill on wildlife in Latin America, which can guide research and conservation actions for species and areas. As the applied approaches are widely replicable,
this document can be also conceived as a reference for future works in other regions of the
world.