Artificial nightlight alters the predator-prey dynamics of an apex carnivore

Artificial nightlight is increasingly recognized as an important environmental disturbance that influences the habitats and fitness of numerous species. However, its effects on wide-ranging vertebrates and their interactions remain unclear. Light pollution has the potential to amplify land-use change, and as such, answering the question of how this sensory stimulant affects behavior and habitat use of species valued for their ecological roles and economic impacts is critical for conservation and land-use planning. Here, we combined satellite-derived estimates of light pollution, with GPS-data from cougars (Puma concolor; n = 56), mule deer (Odocoileus hemionus; n = 263), and locations of cougar-killed deer (n = 1,562 carcasses), to assess the effects of light exposure on mammal behavior and predator-prey relationships across wildland-urban gradients in the southwestern United States. Our results indicate that deer used the anthropogenic environments to access forage and were more active...