Understanding animal-road interactions for proper mitigation: stopping the recurrent roadkill of Giant Anteaters

Abstract

The Brazil’s Cerrado support the largest remaining populations of Giant anteaters. However, today this biome is being heavily fragmented by an ever-increasing road network, and Giant anteaters are one of the most frequently road-killed species.

To address this threat, data on why, when, and how anteaters interact with roadways is urgently needed. We have recently initiated a four-year research project in Mato Grosso do Sul, aiming to assess the impact of roads on Giant anteater populations in the Brazilian Cerrado in order to understand how roads in the Cerrado are affecting anteater population persistence.

A total of 19 individuals have already been fitted with GPS loggers and their data allowed us to verify that anteaters have highly variable behaviors toward roads, ranging from complete avoidance to crossing movements on a daily basis. Alongside, we are performing systematic roadkill surveys every two weeks on 1,300 km of highways; and the numbers have confirmed a high roadkill rate for this species (150 individuals in less than one year). Interestingly, structured interviews on truck drivers and other citizens allowed to discredit an old myth that truckers run over animals on purpose. Finally, remote sensing information allowed us to quantify the deforestation amount and rates since 1970’s in the study area. Based of movement data, the giant anteaters seem to favor forest-open areas edges, which have been increasing with increasing deforestation. Along with the disappearance of Jaguar, its natural predator, we questioned whether the high number of road killings may be due, at least in part, to a population increase of this species. Nevertheless, the effects of increasing traffic volumes and new roads being opened and/or paved, are certainly main causes of such mortality.

Altogether, our project will provide important information on effect of roads on animal movement behavior, population structure and health condition. Research findings will then be used to develop landscape and road management guidelines to mitigate the impact of road mortality on anteater populations.