Center for Conservation Biology- Human Impact on Grizzly Bears

Background

Conservation and management of species at risk demands cost effective methods for rapidly monitoring change in animal abundance, distribution and physiologic health over time.

We developed such methods for monitoring impacts of human disturbances on grizzly and black bear populations on the east slope of the Canadian Rockies. These populations are exposed to a variety of human pressures including mining, forestry, oil and gas development and exploration, transportation corridors, trapping, hunting, and public recreational use.

Using Non-invasive Methods to Monitor Impacts of Human Disturbance on Grizzly and Black Bear over Large Geographic Areas.

Methods

Detection dogs were trained to locate feces (scat) from grizzly and black bears, while sampling contiguous grid cells across the 5,200 km² study area.

Sample locations were recorded using a Global Positioning System (GPS).

DNA extracted from feces was used to determine the species, gender, and identity of the individual that left each sample.

Data on individual identifications were then applied to mark-recapture models to estimate population abundance.

Stress and reproductive hormones extracted from these same fecal samples were used to indicate the physiologic health of these individuals.

Data were then layered onto a Geographic Information System (GIS) that also included location-specific data on human disturbances over the landscape.

Results

Grizzly bears, but not black bears, avoided areas of high tourist densities within the national park, while both species concentrated in the multiple human use areas outside the park. The bears appeared to be drawn to the ephemeral food sources created by the chronic disturbances in these multi-use areas. Grizzly bears also had lower levels of physiological stress, better body condition, and more successful reproduction in the high disturbance areas outside the park. Unfortunately, these areas were also more accessible to poachers, creating a population sink. Five grizzly bears were poached in this area during the three years of our study. Moreover, no old female grizzly bears (>15 yrs) were found in these areas, despite being relatively common in the neighboring national park. Presumably, resident females were being killed before reaching old age in the multi-use areas.

Figure A. Fecal hormones suggest lower stress levels (cortisol metabolites).

Figure B. Fecal hormones suggest higher conception rates (progestins) in the north.

Implications

The integrative tools of this study allowed comprehensive coverage of large remote areas, providing data on abundance, distribution and physiological health of grizzly and black bears. Based on these results, we recommended reducing off-road vehicle access as a means to mitigate poaching impacts on grizzly bears. We also recommended tighter monitoring of tourist behavior in Japser National Park , including harsh penalties for tourists who leave their cars in the vicinity of bears.

Acknowledgements

Detection dog methods were developed in collaboration with the K-9 unit of the Washington Department of Corrections. This project was supported by National Fish and Wildlife Foundation and the Foothills Model Forest (Parks Canada, Alberta Fish and Game, Canadian timber, oil, and coal industries) and the Center for Conservation Biology.

Publications

/Media

*Click the window below to view a 12 minute video on the utilization of scat dogs in Alberta. The video orginally aired on Discovery.Canada and was titled "Grizzly Series".