Tracking Bear Movement in Yosemite

With funding from the Yosemite Conservancy, the National Park Service was able to upgrade their bear tracking collars from radio telemetry to GPS which has an unlimited range and is more accurate.
Black bear eating berries

Black bear eating berries

So what do bears do all day?

That question piqued the interest of the National Park Service as well, so for the first time, wildlife managers in Yosemite will map and monitor where black bears go when they wander out of park boundaries in an attempt to figure out just what they’re up to.

"This project will expand the park's understanding of Yosemite's black bear population, and help to keep bears wild and visitors safe," Yosemite National Park Superintendent Don Neubacher said in a press release.

Much of the funding for the project, roughly $70,000, comes from Yosemite Conservancy donations. This funding will help the NPS buy GPS collars that will monitor the bears, providing insight into how they use the majority of Yosemite’s backcountry space. The GPS program has already been used to understand the movement of Yosemite’s bighorn sheep population.

For the past 10 years bear movement was tracked using radio telemetry, a system in which radio signals convey information from one location to another. The downside of this system: Once a bear leaves a developed area, its movements are tough to track.

"Yosemite Conservancy funding helps us to achieve our bear management goals of keeping healthy natural populations of black bears as independent from human influence as possible," Neubacher said.

That’s an important factor in keeping both bears and park visitors safe. With the new GPS program, coupled with existing radio telemetry tracking, the NPS hopes to prevent incidents and curb bears’ interest, and sadly in some cases reliance, on human food.

Map tracking bear movement

Map tracking bear movement

The Yosemite NPS Facebook page featured the above map showing the movements of one bear over the course of two days in August, you can see that the bear started off in the rocks above Housekeeping Camp, visited Yosemite Lodge, Yosemite Village, Housekeeping Camp, and Lower Pines Campground, then raced up a steep ledge to Glacier Point, made a circuit around Sentinel Dome, then headed down a steep route back to Yosemite Valley, ending up back where the bear started nearly 48 hours later.

Keeping Bears Separate from Humans

Because the NPS is so aware that interaction between bears and humans can be harmful to both parties, it’s taking preventative action.

Driving through the park you’ll likely notice the “Red Bear-Dead Bear” signs, which mark a site where a vehicle hit a bear. Seems a little gruesome, but it’s a good reminder for drivers to slow down, go the speed limit and be aware that wildlife commonly wander along the roadsides.

Interestingly, since Yosemite began the project in 2007 it has received more reports of bear-vehicle collisions. NPS officials aren’t sure if that’s because more bears have actually been hit or if the sign campaign has raised enough awareness that more incidents are reported.

Park rangers are also more aware of the danger bears face when they’re exposed to human food. Although early in Yosemite’s history the NPS fed the bears for entertainment and dumped trash in “bear pits” to entice bears away from campgrounds and lodging areas, officials now understand that bears that get used to human food can change their natural behavior, often causing them to become more aggressive. This can lead to dangerous confrontations and property damage.

Now, visitors will find bear-resistant garbage cans and dumpsters throughout the park, as well as bear-proof food lockers (known as “bear boxes”) at campsites, parking lots and major trailheads.