Nowhere to hide: Effects of linear features on predator–prey dynamics in a large mammal system

• Published in: Journal of Animal Ecology
• Main Authors: DeMars, Craig A., Boutin, Stan
• Other Authors: Börger, Luca, Canadian Wildlife Federation, Natural Sciences and Engineering Research Council of Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; caribou
• Online Access: http://dx.doi.org/10.1111/1365-2656.12760; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1365-2656.12760; https://onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2656.12760; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/1365-2656.12760; https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2656.12760

Abstract Rapid landscape alteration associated with human activity is currently challenging the evolved dynamical stability of many predator–prey systems by forcing species to behaviourally respond to novel environmental stimuli. In many forested systems, linear features ( LF s) such as roads, pipelines and resource exploration lines (i.e. seismic lines) are a ubiquitous form of landscape alteration that have been implicated in altering predator–prey dynamics. One hypothesized effect is that LF s facilitate predator movement into and within prey refugia, thereby increasing predator–prey spatial overlap. We evaluated this hypothesis in a large mammal system, focusing on the interactions between boreal woodland caribou ( R angifer tarandus caribou ) and their two main predators, wolves ( C anis lupus ) and black bears ( U rsus americanus ), during the calving season of caribou. In this system, LF s extend into and occur within peatlands (i.e. bogs and nutrient‐poor fens), a habitat type highly used by caribou due to its refugia effects. Using resource selection analyses, we found that LF s increased predator selection of peatlands. Female caribou appeared to respond by avoiding LF s and areas with high LF density. However, in our study area, most caribou cannot completely avoid exposure to LF s and variation in female response had demographic effects. In particular, increasing proportional use of LF s by females negatively impacted survival of their neonate calves. Collectively, these results demonstrate how LF s can reduce the efficacy of prey refugia. Mitigating such effects will require limiting or restoring LF s within prey refugia, although the effectiveness of mitigation efforts will depend upon spatial scale, which in turn will be influenced by the life‐history traits of predator and prey.