Planning for carnivore conservation should be at the forefront of our minds in the Pacific Northwest. Wolves are slowly returning to Washington and Oregon, with the first pack confirmed in each state in 2008. Grizzlies have become so rare that October 2010 marked the first confirmed grizzly sighting in the Cascades in 15 years; the US Fish & Wildlife Service estimates that only 20 grizzlies live in the entire North Cascades. Wolverines are being considered for Endangered Species Act protection. Protecting carnivores — critical players in keeping ecosystems healthy — requires extensive research to identify the best areas for protection.
To maintain healthy ecosystems, we need to protect carnivores
Carnivores are essential components of ecosystems, keeping prey species populations in check. When wolves were wiped out in Yellowstone, deer and elk populations boomed; overgrazing prevented new growth from surviving and even caused shifts in natural vegetation patterns. Since wolves were reintroduced to Yellowstone National Park, the deer and elk have shifted their grazing areas back to natural patterns – away from open areas and back to more protected locales.
Predators like wolves, bears, cougars, and wolverines are called ‘charismatic megafauna’. They offer an appealing face to habitats that people can relate to more than, say, a possum. Carnivores are often chosen as ‘flagship species’ for conservation efforts because they encourage people to support habitat protection. Carnivores usually have large home ranges, so they are particularly impacted by habitat loss and degradation. Conversely, protecting habitat for carnivores preserves habitat for the less photogenic species that are also important to ecosystems.
As habitat gets subdivided by human development, linking patches of habitat becomes crucial
Large patches of habitat are easily fragmented by human-made barriers like highways and clear-cuts. Mesocarnivores like fishers and martins can be deterred by even small disturbances in their habitat. Maintaining connections between patches of habitat — whether by protecting corridors of habitat that animals can use for travel or by building wildlife-friendly highway over- and under- passes — is vital to carnivore conservation. But how do we determine where conservation efforts will have the greatest effect?
Scientists need to figure out where carnivores spend their time, and the routes that they commonly travel. In an ideal world, their data inform land use by identifying the most important blocks of land for carnivores and enabling conservationists to target their land protection, getting the biggest bang for their buck.
Scientists determine species ranges and patterns of use with a variety of tools
Because carnivores range over large areas and individuals of a species are spread out, they are challenging to study. Based on their goals and their budgets, scientists have several options for learning where carnivores live. Non-invasive methods, which don’t require direct contact with the animal, include tracking, remote cameras, and hair snares; invasive methods include live trapping and radio telemetry.
Each method has pros and cons. To pick the best technique, scientists must weigh the success rate of a technique, its impact on the animals, its cost in both money and labor, and its results. While training to be a wildlife biologist, I’ve used all these techniques except hair snares.
For parts two and three of this series, I’ve gathered photos and described each technique based on my experiences with carnivore science (courses at Western Washington University, a summer field session in Montana, a wildlife internship in Southern California, and volunteer tracking with Conservation Northwest in Washington).
In part four, I’ll wrap the series up with how carnivore science is being implemented in the Pacific Northwest!