Quantifying impacts of recreation on elk (Cervus canadensis) using novel modeling approaches

Abstract

Recreation is known to impact wildlife by displacing and sometimes contributing to the extirpation of sensitive species, underscoring a need for policies that balance wildlife and recreation. This is especially pressing when Indigenous rights necessitate ecological integrity and sustainable populations of wildlife throughout traditional territories. In the Cascade Mountain Range of Washington, USA, Indigenous harvest of elk (Cervus canadensis) is declining, concurrent with increases in recreation. Yet, the nature and magnitude of the effects of recreation on elk are unknown, which prevents land managers from developing informed policies regarding recreation and wildlife management. Here, we use camera traps alongside visitation models that incorporate geolocated social media to quantify the impacts of recreation on elk in western Washington. Random forest models show elk detection rates are relatively constant at low levels of recreation (0–11 people/day), but decrease by over 41% when recreation increases from 12 to 22 people/day. Activity overlap analysis also revealed a shift toward increased evening activity by elk at cameras with higher‐than‐average recreation (∆ = 0.70, 95% CI = 0.61–0.88; χ2 = 7.79, p = 0.02). Generalized additive modeling confirms that elk are more crepuscular or nocturnal at camera locations with more than 10 hiker detections per day. We compare methods for estimating recreation, showing model‐based estimates are more informative than camera‐based estimates. This indicates that recreational intensity along and in the immediate vicinity of trails may be a better predictor of impacts on wildlife than camera‐based estimates that quantify recreational intensity at specific locations along trails. We stress the importance of examining the impacts of recreation on wildlife across multiple spatiotemporal scales and underscore how novel approaches can provide land managers valuable tools to develop management strategies that balance recreation and wildlife. We hope that our work can also serve as a strong example of collaboration between universities, state agencies, and sovereign Indigenous nations toward the broader goal of mitigating the negative impacts of recreation on wildlife.