On 8 June at 13:15, Maris Kruuse will defend her doctoral thesis, “Factors influencing the occurrence and reporting of wildlife-vehicle collisions and the performance of wildlife crossing structures as primary mitigation measures”, to obtain the degree of Doctor philosophiae in geoinformatics.
Supervisors:
Prof. Tõnu Oja, University of Tartu, Estonia
Opponent:
Senior Scientist Dr Jyrki Pusenius, Natural Resources Institute Finland (Luke), Finland
Summary
The dissertation provides empirical data on WVC temporal dynamics and the dependence of WVC numbers on traffic volumes in both Estonian and European level. We also evaluated institutional accountability related to these incidents and the factors that may influence reporting accuracy. Furthermore, we analysed the performance of mitigation measures, using Estonia`s first wildlife overpass monitoring as a case study. We identified temporal peaks in wild ungulates collisions linked to biological cycles and anthropogenic activity and utilized the COVID-19 “anthropause” in spring 2020 to quantify the traffic-WVC relationship, confirming that reduced mobility significantly decreased wildlife mortality across Estonia and Europe. Furthermore, we analysed the legal and financial liabilities of different stakeholders, finding that reporting accuracy may be hindered by the distribution of these responsibilities as well as by driver distress and lack of ability to determine the WVC location or species involved. Therefore, official statistics systematically underrepresent the true extent of these incidents. The findings suggest that integrating hunters into reporting processes is vital for data quality and wildlife management. Eventually we evaluated the utility of Estonia’s first wildlife overpass, demonstrating a clear "adoption curve" where the proportion of large game crossings tripled over years as the crossing structure naturalized, eventually facilitating passage for even more cautious mammal species. Ultimately, this research suggests that as road infrastructure expands, preserving ecological integrity must become a primary driver of transport policy. Effective mitigation requires a multi-faceted approach combining robust data, stakeholder collaboration, and long-term monitoring of crossing structures to enhance both road safety and biodiversity conservation.
