Mammals on the move: patterns, drivers, and solutions for roadkill in Southeastern Brazil

Abstract

Introduction: Collisions between vehicles and wild animals are associated with factors such as habitat fragmentation, as well as ecological and behavioral factors. It is estimated that around 475 million wild animals are killed in road collisions across the country. Objective: To identify the hotspots of wildlife roadkill along our monitored section of the highway, identify the species involved and analyze their association with potential risk factors contributing to wildlife–vehicle collisions, characterize the surrounding environment, and propose mitigation measures. Methods: This study aimed to conduct a systematic monthly survey of wildlife–vehicle collisions along the SP 330 highway in São Paulo, Brazil, covering a total monitored stretch of 331.13 km during the period from 2018 to 2021. We identify and describe hotspots to inform the development of targeted mitigation strategies. Results: There were 3801 occurrences, involving 5364 animals of 28 different orders and 71 species. The Caviidae family, represented by capybaras (Hydrochoerus hydrochaeris) and preá (Cavia aperea) (32.84%, (n = 1762), was the most affected, followed by Dasipodidae, represented by armadillos, nine-banded armadillo (Dasypus novemcinctus) and tatupeba (Euphractus sexcinctus), totaling 15.62% (n = 838) of the cases; Canidae, with wild dog (Cerdocyon thous), maned wolf (Chrysocyon brachyurus), and hoary fox (Lycalopex vetulus) 14.20% (n = 762); Leporidae, with hares (Lepus europaeus) and tapitis (Sylvilagus brasiliensis), accounting for 5.49% (n = 295) of cases; and Myrmecophagidae, giant anteater (Myrmecophaga tridactyla) and anteater (Tamandua tetradactyla), with 196 individuals (3.65%). Among all species, the capybara was the most affected, accounting for 16.36% of deaths (n = 562). It is estimated that 64.0% of the animals died, 35.0% were chased away, and 0.9% were transferred for rehabilitation. In the Kernel density map, the surrounding areas were anthropized, with some forest fragments present. Conclusions: Roadways affect wildlife populations and their natural behavior.