Human disturbance alters the foraging and spatiotemporal activity of a large carnivore.

Abstract

Carnivore recovery is often promoted to restore ecosystem functioning. However, human-disturbed landscapes can alter the behavior and role of returning carnivores. To evaluate how different dimensions of a carnivore niche are affected across a gradient of human disturbance, we studied 83 pumas (Puma concolor) at seven populations in North and South America. We hypothesized that pumas inhabiting sites with high human disturbance would modify their niche by reducing space use, becoming more nocturnal and diversifying their diets. We quantified how landscape features affected puma home ranges, movement paths, diel activity, and step selection. Using stable isotopes, we quantified individual diet and dietary specialization, and population dietary niche width. Pumas decreased their movement rate with increasing human disturbance while some evidence indicates home ranges were reduced. Unexpectedly, diel activity was unaffected by human disturbance, but pumas decreased movement more during the day in areas with high disturbance. Similarly, pumas avoided highly disturbed areas during the day, but that avoidance was low at night. Finally, individual dietary specialization decreased because of pumas reduced consumption of native ungulates with increasing disturbance, although without changes in the population niche width. Responses to human disturbance were generally consistent across sites, with pumas adjusting their temporal, spatial, and foraging axes to decrease encounters with humans. Our results suggest that human-disturbed landscapes across regions alter the primary niche axes of pumas to construct a new realized niche in human landscapes, which may have important consequences for their ecological interactions and the functional role of this large carnivore.