Road rage: impacts of a major highway on wildlife in India’s largest tiger reserve

Abstract

Abstract Roads passing through protected areas are a major barrier to wildlife movement, their spatiotemporal activity patterns, species interactions and habitat use. Roads can thus impact larger ecological processes, with long term consequences for ecosystems. Varying intensities of traffic movement at different hours of the day can varyingly impact mammal occurrence and consequently, influence animal behaviour with long term implications for human-wildlife conflicts. Altered mammal activity in many instances leads to increased mortalities for both humans and wildlife. Here, we assess the impact of vehicular traffic on mammal occurrence, density, and richness in the Nagarjunasagar Srisailam Tiger Reserve (NSTR), India’s largest Tiger Reserve situated in the Nallamala ranges of the central Eastern Ghats of Andhra Pradesh. We used camera traps placed along a National Highway (NH 765) and a relatively undisturbed forest trail (PT) inside the forest to assess the impact of the NH on mammals. We recorded 16 species of mammals using the NH and the surrounding habitat, including endangered and threatened species such as Tiger, Leopard, Sambar, and Dhole. Carnivore richness was significantly higher on the PT than on the NH, and away from the NH than on it. Overall, mammal density was higher on the NH, largely due to higher abundance of herbivores. This study provides the first insights into the impacts of roads on the density and richness of mammals inside a tiger reserve in the largely neglected Eastern Ghats. Our work generates baseline information on the kind of impacts that road building and widening projects, an increasing threat to protected areas globally, can have on mammals.