Wildlife roadkill hotspots on roads crossing Conservation Units in the State of Sergipe, Brazil.

Abstract

Roadkill of wild animals is a significant threat to biodiversity in Brazil, causing numerous animal deaths annually. This study aimed to identify the main locations of roadkill of wild animals on two highways that pass through Conservation Units in the state of Sergipe, Brazil, examining the correlation between roadkill and dry and rainy seasons. From November 2021 to October 2022, 49 surveys were carried out along BR-235, near Serra de Itabaiana National Park, and on the Adil Dantas do Amor Cardoso highway (ADAC), crossing the Mata do Crasto Private Natural Heritage Reserve. The campaigns were carried out on motorcycles, traveling at a speed between 20 and 60 km/h. To identify roadkill points for each highway, Kernel density estimation and species accumulation curves with area extrapolation (Bootstrap) were used, and mortality rates, the 2D K-Ripley test to test the randomness of roadkills and Shannon's diversity index (H'). On BR-235, 63 roadkills were recorded and an average mortality rate of 0.0652 individuals/Km/day, while on the Adil Dantas do Amor Cardoso highway, which has implemented mitigating measures, 15 occurrences were recorded with an average mortality rate of 0.1430 individuals/Km/day. Attraction points generated by the presence of improperly discarded carcasses on BR-235 were also identified. Although not significant, the BR-235 highway showed a positive correlation between precipitation and the frequency of roadkill (rs=0.1426, p=0.5851), while ADAC showed a negative correlation for the same variables (rs=-0.1749, p=0.5675). Understanding the patterns of roadkill and the needs of highways is essential for the development of effective strategies and the establishment of effective mitigation measures, thus minimizing the negative impacts of highways on biodiversity.