Mammalian predator and prey responses to recreation and land use across multiple scales provide limited support for the human shield hypothesis

• Published in: Ecology and evolution Vol. 13; no. 9; pp. e10464 - n/a
• Main Authors: Granados, Alys, Sun, Catherine, Fisher, Jason T., Ladle, Andrew, Dawe, Kimberly, Beirne, Christopher, Boyce, Mark S., Chow, Emily, Heim, Nicole, Fennell, Mitchell, Klees van Bommel, Joanna, Naidoo, Robin, Procko, Michael, Stewart, Frances E. C., Burton, A. Cole
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.09.2023; John Wiley and Sons Inc; Wiley
• Subjects: Alces alces; Arrays; Bayesian inference; Bears; camera trap; Cameras; Carnivores; Community Ecology; Deer; Elk; Forests; Grizzly bears; Habitats; Hypotheses; Land use; Landscape; Logging; mammal conservation; Moose; Mortality; Odocoileus; Parks & recreation areas; Predation; Predators; Prey; protected area; Recreation; Recreation areas; Recreational use; Roads; Shielding; Ursus arctos; Wilderness areas; Wildlife; British Columbia Canada; Canada; protected area; mammal conservation; Bayesian inference; camera trap; recreation
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.10464

Outdoor recreation is widespread, with uncertain effects on wildlife. The human shield hypothesis (HSH) suggests that recreation could have differential effects on predators and prey, with predator avoidance of humans creating a spatial refuge ‘shielding’ prey from people. The generality of the HSH remains to be tested across larger scales, wherein human shielding may prove generalizable, or diminish with variability in ecological contexts. We combined data from 446 camera traps and 79,279 sampling days across 10 landscapes spanning 15,840 km2 in western Canada. We used hierarchical models to quantify the influence of recreation and landscape disturbance (roads, logging) on ungulate prey (moose, mule deer and elk) and carnivore (wolf, grizzly bear, cougar and black bear) site use. We found limited support for the HSH and strong responses to recreation at local but not larger spatial scales. Only mule deer showed positive but weak landscape‐level responses to recreation. Elk were positively associated with local recreation while moose and mule deer responses were negative, contrary to HSH predictions. Mule deer showed a more complex interaction between recreation and land‐use disturbance, with more negative responses to recreation at lower road density or higher logged areas. Contrary to HSH predictions, carnivores did not avoid recreation and grizzly bear site use was positively associated. We also tested the effects of roads and logging on temporal activity overlap between mule deer and recreation, expecting deer to minimize interaction with humans by partitioning time in areas subject to more habitat disturbance. However, temporal overlap between people and deer increased with road density. Our findings highlight the complex ecological patterns that emerge at macroecological scales. There is a need for expanded monitoring of human and wildlife use of recreation areas, particularly multi‐scale and ‐species approaches to studying the interacting effects of recreation and land‐use change on wildlife. Outdoor recreation is widespread, with uncertain effects on wildlife. We used 446 camera traps in Western Canada to measure mammal predator and prey multi‐scale responses to recreation, according to the Human Shield Hypothesis. Responses were mostly local and depended on co‐occuring disturbances and, contrary to predictions under the hypothesis, most ungulates avoided recreation while carnivores did not.