The influence of ecotourism on grizzly bear activity depends on salmon abundance
New study reveals that grizzly bears shy away from bear ecotourism sites when visitor numbers are high, except when salmon is scarce.
A new study, “Influence of ecotourism on grizzly bear activity depends on salmon abundance in the Atnarko River corridor, Nuxalk Territory” released today in the journal, Conservation Science and Practice, finds that grizzly bear activity is affected by ecotourists in diverse ways that depend on how many salmon are present in the ecosystem.
When salmon are abundant, grizzlies reduce their activity in stream segments that flow by land-based ecotourism sites during weeks when visitor numbers were high. When salmon are scarce, however, the opposite pattern occurred: bear activity increased when there are more people present in the ecotourism areas, which offer some of the river’s easiest-to-catch fish.
Which bears are present also depends on conditions. During daylight hours, and when tourist numbers are high, more bear activity is comprised of moms with cubs and sub-adults. These are the types of bears that are apparently more tolerant of people, and can even use tourists as ‘human shields’ against dominant male grizzly bears, which can kill other bears.
Collectively, these patterns suggest that grizzlies can tolerate humans when food is constrained to places where numbers of people are high or when there is a possible safety advantage among humans. But when food is available elsewhere, bears that are less tolerant of people re-allocate their time away from human activity, where they can presumably find fish beyond areas with many tourists.
“The highest number of land-based bear viewers occurred at a site that is not formally designated forbear viewing. In a context of scarce salmon and high visitor numbers, bears have a choice: stay with a crowd of people and eat, or move and possibly forgo an easy meal. A low-food, high-human condition isn’t ideal for bears who are less tolerant of people.”
Kate Field, PhD student with the University of Victoria and Raincoast Conservation Foundation.
The study was solicited by managers from the Nuxalk First Nation and British Columbia Parks to understand the potential influence of ecotourism on grizzly bear activity in the Atnarko River Corridor, within Nuxalk Ancestral Territory. Researchers analyzed three years of data collected from remote cameras during the ecotourism season, which occurs in the pre-hibernation period when bears need to eat abundant salmon to stay healthy.
“This important work ensures that BC Parks is meeting its conservation mandate. The successful outcome of this research is the result of strong collaboration between Nuxalk Nation, BC Parks, University of Victoria and Raincoast Conservation Foundation and allows managers to know if conservation objectives established for wildlife viewing are being met.”
Steven Hodgson, Parks and Protected Area Section Head out of Bella Coola.
The authors note that bear culture, personality, and individual capacity for logic and thought are important individual traits of grizzlies, which are not captured via remote camera detections, a measure that pools the detections of unknown individuals. Whereas this new study confronts only one of three lines of inquiry (i.e., broad activity patterns via analysis of remote camera data) associated with the research project, ongoing analyses of behavioral and genetics data will aim to yield more detailed inference at the individual bear level.
“Our study’s findings remind us that we need to take extra care of our bears and the salmon they rely on. Nuxalk have co-existed with bears for millennia, and it’s our responsibility to ensure this continues in the context of ecotourism in the Atnarko spawning grounds as well.”
Jason Moody, Nuxalk Fisheries and Wildlife Program Manager and study partner.
Citation
Field, K. A., Short, M. L., Moody, J. E., Artelle, K. A., Bourbonnais, M. L., Paquet, P. C., & Darimont, C. T. (2024). Influence of ecotourism on grizzly bear activity depends on salmon abundance in the Atnarko River corridor, Nuxalk Territory. Conservation Science and Practice, e13097. https://doi.org/10.1111/csp2.13097
Abstract
Ecotourism management can draw on theory and data related to non-con-sumptive effects of risk on wildlife. The asset protection principle (APP) predicts that variable food supply and its associated risks will affect antipredator behavior; responses to predation risk should dominate when food reserves are high, while nutritional risk becomes more important when food reserves are limited. Additionally, the human shield hypothesis (HSH) describes how some individuals might seek human presence if it repels potential sources of risk. Using camera traps, we used generalized linear mixed effects and multinomial regression models to test components of the APP and HSH where ecotourism co-occurs with grizzly bear (Ursus arctos) foraging during hyperphagia. When salmon abundance was high (+1 SD), bear activity(weekly detections) decreased by 13% with every 100 visitors/week. Underlow salmon conditions, bear activity increased with visitor numbers, creating ‘high bear-high visitor’ conditions. Consistent with HSH, detection data revealed an increased likelihood of detecting subordinate age-sex classes compared with adult males when visitor numbers were high. Our findings suggest that when salmon are low, managers might consider limiting visitors to mitigate disturbance. More broadly, understanding how wildlife allocate anti-predator behavior as a function of risk and food can inform conservation science and practice.
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Authors and affiliations
Kate A. Field1,2
Monica L. Short1,2
Jason E. Moody3
Kyle A. Artelle1,4,5
Mathieu L. Bourbonnais4
Paul C. Paquet1,2
Chris T. Darimont1,2
- Department of Geography, University of Victoria, Victoria, Canada
- Raincoast Conservation Foundation, Sidney, Canada
- Nuxalk Fisheries and Wildlife, Nuxalk Stewardship Office, Bella Coola, Canada
- Department of Earth, Environmental and Geographic Sciences, University of British Columbia Okanagan, Kelowna, Canada
- Department of Environmental Biology, and Center for Native Peoples and theEnvironment, State University of New York College of Environmental Science and Forestry, Syracuse, United States
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