The Cascade Rare Carnivore Survey sampled for rare carnivores in the North Cascades Ecosystem (NCE)this last summer from July to October 2010. The sampling survey focused on grizzly bear, gray wolf, Canada lynx and wolverine using hair snare corrals and some remote digital cameras. Over 1,196 hair samples were collected for DNA analysis from 191 total sites sampled with corrals.
The North Cascades Ecosystem (including parts of Canada) is one of the largest contiguous blocks of federal land remaining in the lower 48 states. As stated in the report, carnivores are very difficult to study given their large area requirements, low densities and elusive behavior. The researchers felt their best method for detecting the sample species was by using non-invasive hair snagging and remote cameras. The specific areas sampled were the Pasayten Wilderness and the North Cascades National Park, the mountainous area North and South of Highway 2, the Glacier Peak and Alpine Lakes Wilderness, and the area North of the I-90 corridor.
The hair-snare corrals are composed of a single strand of barbed wire strecthed around four or more trees at a height of about two feet. A liquid scent lure was left in the center of the corral as an attractant and animals climbing over or under the wire to enter the corral generally left a hair sample on one or more strands or barbs. When found In the field, hair samples were immediately collected and stored in plastic containers for later DNA analysis. In addition, 47 remote cameras were deployed in the study area and served as a useful tool in validating the effectiveness of the hair sampling. The researchers found that when a bear photo was captured at a site on a remote camera, 98% of the time a hair sample was also captured on a strand of wire at the same site.
Results from this study will be used to further the mission of state and federal agencies to recover or maintain viable populations of carnivores in the North Cascades Ecosystem. The results of the DNA analysis of the hair samples collected will be available sometime in the summer of 2011. Understanding the affects of highways on gene-flow among carnivores, and determining the distribution and population status of grizzly bears in the NCE are some of the important questions this study may answer.
For a full copy of the Cascade Rare Carnivore Survey Report contact the Okanogan-Wenatchee NF or the Washington Department of Fish and Wildlife.