Spatial ecology of recolonized elk in agricultural landscapes of the Northern Great Plains

Abstract

Mitigating human-wildlife conflict for recolonized populations of large mammals requires understanding spatial responses to variation in natural and anthropogenic landscape features. Elk recolonized Nebraska, USA in the 1960's and have since expanded geographically and numerically. Elk are a high-profile species of management concern that cause agricultural crop depredation but are valued as a harvested species. Managers lack empirical understanding of their spatial ecology in agriculturally dominated landscapes of much of the Northern Great Plains, resulting in uncertainty for depredation and harvest management. We quantified home range size and seasonal movements of 153 GPS-collared elk (103 females, 50 males) in Nebraska across gradients of natural habitat and agriculture. Elk used smaller home ranges in areas with greater vegetative cover, more cornfields, and more evenly distributed forage. Elk used larger home ranges in areas with more roads and development. Thus, human disturbance fragments the landscape for elk, while also providing agricultural subsidies. Elk moved greater distances to leave areas with greater risk to access areas with substantial cropland when establishing calving and fall ranges. Additionally, elk moved greater distances between seasonal home ranges when transitioning from areas with reduced natural forage. Our results suggest that elk shift space use seasonally to exploit both natural and agricultural forage, but that increased availability of natural forage may reduce seasonal movements of elk into cropland. Thus, management of elk in agricultural landscapes should prioritize providing quality natural habitat to mitigate human-wildlife conflict. Our work highlights the disparate influence of human disturbance on wildlife space use.