Black bear study sheds light on movement, habitat use

BONNERS FERRY — A young black bear traveled from the McArthur Lake area to the Boundary Creek drainage and back in a year.

 The young black bear was collared in 2011 as part of a study on linkage of wildlife species across highways but it decided to travel away from the highway.

Black bears were collared in the McArthur Lake area, Lookout Pass area and Hwy. 200 area to determine how often they crossed the highway and where they crossed.

In the McArthur Lake area, 14 black bears were collared in the spring and summer of 2011. Three of the bears were killed before collars were collected in 2012. Two of the black bears crossed Highway 95.

In the Highway 200 area, 14 black bears were collared and three were also killed before the end of the study. Two bears crossed Highway 200 and two bears crossed Highway 56.

“Hunter harvest is fine but we want the information,” said Wayne Kasworm, USFWS bear biologist, at the KVRI Grizzly Bear subcommittee meeting.

In the Lookout Pass area, 16 bears were collared and five killed before the end of study. Four of the bears crossed I-90 and one bear crossed both I-90 and Highway 200.

“I-90 had the most crossings!” said Kasworm. “That was a little bit of a surprise to me.”

To maximize opportunities for black bears to cross the highway, most bears were trapped within a few miles of the highways.

With previous studies on Highway 3 and Highway 95, a total of 99 black bears have been collared. Those collars have provided between 1,000 to 2,000 radio locations.

The locations showed that many of the bear’s home ranges abutted the highways. Home ranges of female black bears are about 10 square miles.

The locations also give more insight into movement and habitat use said Kasworm.

Idaho Fish and Game biologists and USFWS biologists will use modeling to determine what habitat the black bears are using based on the radio locations. Then biologists will identify where that habitat meets the highway and predict where black bears might cross.

These predictions will help highway departments identify areas that might need wildlife structures or more signs to alert drivers to wildlife crossings.

The final report is scheduled to be released in 2014.