By Advocate | January 16, 2012 at 12:05 am |
Last March, “M17″ — an adult male bobcat who was captured, fitted with a GPS collar and released by researchers the month before — did a peculiar thing.
The animal had been hanging out just west of Boulder, roaming the foothills from Lee Hill Drive south to Boulder Canyon, when the researchers trapped him. But in March, he began a trek to the west along the southern lip of Boulder Canyon, swinging south of Nederland and north of Rollinsville.
M17 then made himself at home along the Continental Divide, cruising the section of mountains sandwiched between James Peak and Eldora.
Such long-distance romps may be rare for bobcats — or at least these types of travels have not been well documented in the existing scientific literature.
So M17′s trek will be one of the things that Jesse Lewis, a doctoral student at Colorado State University, looks into over the next two years as he works to sift through the data he’s collected from 20 bobcats he’s collared in the Boulder area and another 20 on the Western Slope.
In all, four adult male bobcats fitted with GPS collars in the Boulder area made long-distance trips. M17 actually returned to the Boulder area around Thanksgiving. Two other bobcats traveled south from Boulder and spent several months around Golden, and a final bobcat traveled to an area near Empire, and so far, hasn’t left.
These movements seem odd, Lewis said, because adult bobcats typically stake out and then stay in a home range.
“Our general observations are that bobcats definitely have a defined territory, especially adults,” Lewis said. “For the few bobcats that have made these really long-distance movements, it has been a surprise because it hasn’t been reported before.”
When bobcats do travel, it’s often young males in search of a territory of their own, Lewis said. But the males in Lewis’ study are prime-age cats who should be able to stay in and defend their territories if they want.
One of the reasons observations of long-distance movements might be lacking from other studies is that, in the past, bobcats were frequently collared with VHF devices that emit a radio signal. But radio tracking requires that the researcher be able to pick up the radio signal.
“Previous research has been with VHF collars,” he said. “You have to go out there either from a fixed-wing aircraft or from the ground and triangulate where you think the animal is.”
But if animals have moved far away from the last place their signal was picked up, researchers may have a hard time finding them — and therefore tracking their long-distance movements.
“The GPS collars give us the whole story,” Lewis said.
Lewis has been working on his bobcat project since 2009, and his work included setting up 40 motion-activated cameras on the Front Range as well as collaring the animals. The images captured by the camera — including 600 pictures of bobcats and 500 photos of mountain lions — will help Lewis estimate the number of bobcats in the area.
The GPS data will also help the researchers understand how bobcats interact in the study area. Lewis will also be able to compare bobcat behavior in the populated Front Range to behavior in the Western Slope.
Heather Swanson, a wildlife ecologist for Boulder Open Space and Mountain Parks, said the department is excited that Lewis is doing his research in the city’s backyard.
“Bobcats are one of the animals on our property that we know are there, but people don’t see them very often because they’re very secretive,” she said. “Any information about population levels or about how they use open space is really helpful to us.”
Contact Camera Staff Writer Laura Snider at 303-473-1327 or email@example.com.
Posted: 01/15/2012 11:00:00 AM MST