Handling griz: How much is enough?
At least 5 percent of the West’s grizzly bears should wear radio collars, researchers say
Grizzly bear researchers begin with a ripe deer or elk carcass, a lure that’s hard for any bear to resist. Once the animal takes the bait, it’s snared by a front paw or caught in a culvert trap, and then tranquilized. Sometimes it’s shot with a tranquilizer dart from a tree stand.
Once the bear is unconscious, researchers may slip an oxygen tube up its nose to help it breathe, and dab salve in its eyes to keep them moist. Then they take the bear’s temperature, clamp a microchip on its ear, and fasten a radio collar around its neck. They clip a swatch of hair, and measure body weight, total length, paw dimensions and fat level. Sometimes they pull a tooth to determine the animal’s age.
Then they back off, while the bear wakes up, shakes off its hangover and ambles away.
A typical capture and collaring takes less than an hour. But it’s a difficult experience, and an increasing number of grizzlies have to endure it. Federal and state scientists have ramped up their efforts to monitor the animals, trying to determine whether the West’s two biggest grizzly populations deserve continued protection under the Endangered Species Act.
Some environmentalists question whether these intrusive monitoring efforts are really necessary. Researchers should show "restraint" when deciding how many bears to collar, says Doug Peacock, author of Grizzly Years, a chronicle of more than a decade of his backcountry observations of grizzlies. "The bears are already bothered enough (by people intruding into their habitat)," Peacock says. "I’m not saying this isn’t a valid course of science, just that we ought to give the bears all the breaks we can."
"A traumatic experience"
More than 50,000 grizzlies live in Canada and Alaska, but only about 1,300 survive in the Lower 48 states, mostly in the Yellowstone National Park region and the Northern Continental Divide ecosystem around Glacier National Park.
Recently, the U.S. Fish and Wildlife Service proposed taking the Yellowstone population off its list of threatened species (HCN, 9/19/05: Yellowstone's Grizzlies: A success story). In the course of the research that led to that proposal, the agency captured 58 bears last year, up from 15 in 1990. Now about 10 percent of the estimated 600 grizzlies in the Yellowstone region wear radio collars.
In the Northern Continental Divide’s population, estimated at 500, researchers began collaring bears last year to determine birth and mortality trends. They want to have at least 25 female grizzlies in collars at all times, and they’ll end up capturing at least twice that many males while trying to get the females, says Rick Mace, a Montana Department of Fish, Wildlife and Parks researcher who coordinates the monitoring program. A few grizzlies get collared because they hang around campgrounds or prey on livestock and bear managers want to keep them under surveillance. But most collarings are done strictly for research.
Many researchers say all the handling doesn’t affect the grizzlies’ behavior after they’re released. "It’s a traumatic experience, and scary, but these guys aren’t capable of holding a grudge," Mace says. But studies show that 16 to 20 percent of the collared grizzlies end up getting into trouble later, sometimes even attacking people.
Researchers think that’s a normal rate for grizzly problems, but they also acknowledge that they’re only guessing. Because they can’t monitor uncollared bears, they have no way to compare their behavior with that of collared bears. It’s a "Catch-22," says Charles Schwartz, leader of the Yellowstone region’s Interagency Grizzly Bear Study Team.
Most collars send signals that note the bear’s location only twice a week, when researchers fly overhead in airplanes with radio receivers. But the newest versions use satellite Global Positioning System technology to record a bear’s location once an hour, 24 hours a day. Recent studies using GPS collars have illuminated a previously unknown world: what grizzlies do at night. The bears come surprisingly close to houses, even right into towns. "If we didn’t have that handling, we wouldn’t know much of anything about the bears," says Chris Servheen, grizzly bear recovery coordinator for the U.S. Fish and Wildlife Service.
The other big, federally protected predators that wear radio collars — wolves — get handled even more frequently than grizzlies. In 2004, about 30 percent of the 835 wolves in the Northern Rockies had collars. But Ed Bangs, the federal wolf recovery coordinator, would like to see the use of collars reduced significantly, partly because of the expense, but also for more philosophical reasons.
"Americans are techno-freaks and control freaks, and that gets applied to wildlife," Bangs says. "I think it’s an insatiable desire to know everything. Telemetry helps you do that. But I believe in mystery in life. Restoration of wildness, and all those kinds of values, they’re based on not knowing, on unpredictability, and on not being in control. Why can’t we turn loose?" But Bangs acknowledges that it’s unlikely that collaring rates will be reduced anytime soon.
Even if the Yellowstone grizzlies are taken off the list of threatened species, scientists plan to continue monitoring how the population fares without protection. Because each collar lasts only a few years, in order to keep tabs on the West’s grizzly bears, researchers will have to continue high overall capture rates for many years to come.
Colleen O’Brien is a freelance writer based in East Glacier, Montana. Ray Ring is HCN’s Northern Rockies editor, based in Bozeman, Montana.