Missoula doesn't have an urban bear problem, so much as ursine tourists.

That's what pops out of a midpoint review of a three-year study of black bears in the Rattlesnake and Grant Creek valleys. Radio-collar mapping of 10 bears shows they spend most of their time in the mountains, but come to town for apple season.

"Another thing we noticed - the (mapping) points in town in people's yards are only at night," said Jerod Merkle, a University of Montana wildlife biology student who's running the study with the state Department of Fish, Wildlife and Parks. "Bears are usually diurnal animals. They're active in the early morning and evening, not solely nocturnal. So they may be changing lifestyle to feed on urban foods."

Merkle's research will break new ground in the urban wildlife field, according to FWP bear manager Jamie Jonkel. There's little hard data showing how bears behave on the edge of town. So finding out the times of year they come in, the times of day, the types of food or habitat they seek, and the trouble they get into all help guide urban bear management policies.

"If it all comes together, it might be a good methodology for other communities," Jonkel said. It will also contribute to Missoula's own bear buffer zone policy, which seeks to reduce the people-bear conflicts in its surrounding valleys.

Missoula's bear problem spiked in the late 1990s, when a particularly tough food year drove many bears out of the woods. The combination of spring frosts and summer droughts dried up much of the backcountry berry, fruit and grass supplies bears depend on. So they came to check out Missoula's fruit trees, fertilized lawns and garbage cans.

"We had had a bear digging through roofs into pantries, bears breaking into cars," Jonkel recalled. "There were so many bears killed by trains and cars, road-killed in the Rattlesnake, bears rushing out of alleyways and getting hit."

The bears that survived made mental maps of the new food source, and passed the knowledge on to their cubs.

Merkle had developed an interest in carnivores as an undergraduate student at the University of Arizona, and expanded on it with master's degree studies at UM. Last year, he teamed up with Boone and Crockett wildlife conservation professor Paul Krausman, who'd just landed a grant to buy radio collars and other equipment. They devised the three-year research plan for Missoula's bears.

With help from FWP biologists, Merkle trapped 10 bears in the two northern valleys and attached the collars this summer. The transmitters feed each bear's location into a computer every three hours. For most of this summer, the bears prowled the Rattlesnake Wilderness. But come mid-August, they crossed the city limits and explored all the way to the Interstate 90 freeway.

Only one bear crossed that southern boundary, and then only for a few hours. But the rest filled the Rattlesnake Valley with plot marks. The Grant Creek drainage also got explored, but to a lesser extent. Merkle said that could be because most of his collared bears were caught in the Rattlesnake fringe.

Some of the bears have already headed into dens for the winter, although most appear to be active for another few weeks. Once they're hibernating, Merkle and Krausman will analyze the data and hypothesize about the movement patterns. Next year, Merkle will continue to track the bears' motions until the collars automatically drop off in October 2010.

"Scientists don't have any idea about bears living in town," Merkle said. "We don't know their role in the ecosystem. Have they completely changed biology to live off what humans do? We need information to explain that question."

Reporter Rob Chaney can be reached at 523-5382 or at rchaney@missoulian.com.