Fauna em risco : o perigo dos atropelamentos para vertebrados em trecho da BR-101 em Sergipe

Abstract

Highways, essential for socioeconomic development, threaten ecosystem preservation by fragmenting habitats and causing vertebrate deaths due to collisions. In Brazil, where the road network is extensive and biodiversity is rich, this problem worsens, varying by region, climate, and animal groups. This study, conducted on a 34 km stretch of BR-101 in Sergipe, identified the vertebrate species most affected by vehicle collisions, investigated the influence of precipitation on these collisions, the uniformity of records throughout the year, and the differences in records between single and dual carriageways in the sampled stretch. Data were collected biweekly by two observers in a vehicle at 40-50 km/h from May 2023 to April 2024. In total, 146 collisions involving 40 species were recorded, with a daily rate of 0.089 individuals/km/day and an annual rate of 32.48 ind/km/year. Mammals were the most affected group (38.36%), followed by amphibians (26.03%), birds (19.86%), and reptiles (15.75%), with the crab-eating fox (Cerdocyon thous; 16.44%), cane toad (Rhinella diptycha; 12.33%), black vulture (Coragyps atratus; 6.85%), and the musurana snake (Boiruna sertaneja; 3.42%) being the most hit species of each group. Precipitation negatively influenced the number of mammal collisions, showing a decrease in records as rainfall increased, slightly explaining this decrease. Overall, the vertebrate collision records were not uniform throughout the year, influenced by a higher concentration of amphibian collisions from February to April. This can be explained by the fact that the anurans' reproductive period occurs precisely during these usually rainy months in the region. More collisions were observed on dual carriageways, possibly due to the greater width of the road and central barriers that hinder animal crossing. The results reinforce the need for mitigation measures, such as wildlife crossings and better signage, to reduce vertebrate mortality on highways.