Ecological and Climatic Drivers of Wildlife Road Mortality in Kenya’s Athi-Kapiti Plains

Roads and habitat fragmentation pose significant conservation challenges for many animals, yet the environmental factors that influence roadkill risk remain poorly understood. In Kenya, the Nairobi–Mombasa Highway cuts through the ranges of numerous wildlife species within one of the country’s most biodiverse regions, the Athi-Kapiti Plains. To investigate the environmental factors influencing roadkill risk in this region, we combined remote sensing data on long-term drought (Standardized Precipitation Evapotranspiration Index, SPEI) and vegetation greenness (Normalized Difference Vegetation Index, NDVI) with 6,240 km of road transect surveys conducted in 2023 and historical roadkill records from 2020–2022. We recorded 218 wildlife roadkills involving 11 species, predominantly plains zebras ( Equus quagga , 69%), spotted hyenas ( Crocuta crocuta ), and Maasai giraffes ( Giraffa camelopardalis tippelskirchi). Prolonged drought, reduced vegetation productivity, and wildlife use intensity emerged as key predictors of roadkill risk along the Nairobi–Mombasa Highway across the Kenya’s Athi-Kapiti Plains. These factors interact to increase animal movement across roads, especially during dry periods when animals seek water and forage. We also found roadkills to be clustered near artificial water points, suggesting these sites may function as ecological traps by concentrating wildlife in high-risk zones. Our findings suggest that drought-driven declines in food availability may force animals to travel farther and cross roads in search of resources, increasing roadkill risk. This interaction between drought and road mortality is particularly concerning, as both represent significant threats that may intensify under climate change. Our results highlight how climatic stress, habitat degradation, and wildlife use intensity jointly shape roadkill patterns.