Parks Canada is testing non-electrified fence designs to help keep bears off the national park’s roads and highways.
Parks began a trial of several low maintenance non-electric fence designs in 2014 and continued through this year, trying to find a design that would prevent bears from climbing over wildlife exclusion fences.
The 2015 data is still being collected and analyzed, but preliminary results clearly illustrate that motivated bears will uncover points of weakness in the fence and focus their efforts on those points.
Park officials say they have improved highway fencing in Banff and parts of Kootenay, including with a graduated page wire to prevent smaller animals from squeezing through near the bottom, and a buried apron and concrete gate slabs to prevent animals from digging under.
“Despite these efforts, the current highway fence design is permeable to black bears and grizzly bears because they can climb over the fence,” said David Gummer, Banff’s wildlife ecologist, in the recently released 2014 Report from the Field.
“Consequently, both species face a risk of human-caused mortality and injury.”
The Outlook could not interview Gummer for the story because all Parks Canada employees have been banned from speaking with the media since the Oct. 19 election was called.
As part of the trial of new or modified fence designs, Parks Canada established a test fence site baited with carrion to try to attract bears to the area and motivate them to breach the fence.
Several video and remote still cameras were installed to record all wildlife behaviour at the test site for analysis.
The current fence design being tested is similar to the current standard wildlife fence used on the Trans-Canada Highway, but with the addition of a metre-wide overhang at the top of the fence.
Parks Canada has recorded grizzly bear, black bear, wolf, cougar, coyote and wolverine so far.
At least four different grizzly bears and one black bear have visited the test site. The fence successfully deterred all of these bears except one, bear 122, the large dominant male in the Bow Valley.
The bears have attempted to push against the fence, dig under and climb over.
Gummer said grizzly bear 122 gained access twice by creating a hole through the fencing at a point of weakness in the design, noting the weakness came from a one metre by one metre hole that was cut by staff to enter the site.
“Although this access point was covered by an overlapping piece of fencing and was wired shut, grizzly bear 122 was able to exploit the weak area, which did not have the same structural integrity as the rest of the fence,” he wrote.
“We repaired and permanently sealed this area to prevent further access and encourage wildlife to attempt to access the site by other means. This highlights how adept bears are to exploit a minor design vulnerability when motivated with significant food reward.”
In addition, Gummer said visible bait proved to be a much stronger incentive to access the enclosure than bait hidden inside a blue barrel.
He said chainlink skirting effectively deterred all attempts at digging, noting the depth of digging never exceeded 40 centimetres, but did expose 60 cm of angled skirting which reinforced the importance of a buried apron to at least one metre.
“At 39 attempts at digging and manipulating the fence, 29 attempts were made at the area with staff access point,” said Gummer.
“The remaining attempts were made along an adjacent panel or at an opposing panel that had a post that was not as firmly anchored in the ground,” he added.
“Preliminary results clearly illustrate that bears will uncover points of weakness and focus their efforts on these points.”
