Effects of vehicle traffic on space use and road crossings of caribou in the Arctic

Abstract

Assessing the effects of industrial development on wildlife is a key objective of managers and conservation practitioners. However, wildlife responses are often only investigated with respect to the footprint of infrastructure, even though human activity can strongly mediate development impacts. In Arctic Alaska, there is substantial interest in expanding energy development, raising concerns about the potential effects on barren‐ground caribou (Rangifer tarandus granti). While caribou generally avoid industrial infrastructure, little is known about the role of human activity in moderating their responses, and whether managing activity levels could minimize development effects. To address this uncertainty, we examined the influence of traffic volume on caribou summer space use and road crossings in the Central Arctic Herd within the Kuparuk and Milne Point oil fields on the North Slope of Alaska. We first modeled spatiotemporal variation in hourly traffic volumes across the road system from traffic counter data using gradient boosted regression trees. We then used generalized additive models to estimate non‐linear step selection functions and road crossing probabilities from GPS‐collared female caribou during the post‐calving and insect harassment seasons, when they primarily interact with roads. Step selection analyses revealed that caribou selected areas further from roads (~1–3 km) during the post‐calving and mosquito seasons, and selected areas with lower traffic volumes during all seasons, with selection probabilities peaking when traffic was <5 vehicles/hr. Using road crossing models, we found that caribou were less likely to cross roads during the insect seasons as traffic increased, but that response dissipated as insect harassment became more severe. Past studies suggested that caribou exhibit behavioral responses when traffic exceeds 15 vehicles/hr, but our results demonstrate behavioral responses at much lower traffic levels. Our results illustrate that vehicle activity mediates caribou responses to road infrastructure, information which can also be used in future land‐use planning to minimize the behavioral responses of caribou to industrial development in sensitive arctic landscapes.

Research Progress of the Impacts of Comprehensive Transportation Network on Territorial Spatial Development and Protection

“…Research on the impact of transportation on protected areas originated from Oxley's analysis of small and medium-sized mammal species and abundance in areas along some highways in Ontario and Quebec, Canada, in the 1970s, which focused on the hazardous effects of highways on biodiversity [113]. After the 1990s, with the start of road ecology research, studies about vegetation cover, species diversity, and the number and size of ecological patches along transportation routes in protected areas began [114,115]. In China, the relevant research began in 2000, and so far, there are mature empirical research results covering the analysis of the impacts of highways on land, water, flora and fauna, acoustic, atmospheric, and other factors in nature reserves and the construction of an evaluation index system [116].…”