The friendliness of wildlife-friendly fencing is under study on southeastern Alberta ranchlands.
The focus is on pronghorn, also known as antelope, which crawl under fences rather than jump over as they move around this northern part of their native range.
The Alberta Fish and Game Association has spearheaded fence modification efforts for about six years, in which the lower strand on barbed-wire fences is raised to
18 inches above ground and in some cases replaced by a strand of smooth wire.
The question now is whether the modifications are helping.
Researchers in Alberta and Montana sought to find out. Using remote cameras to photograph pronghorn, they compared the raised barbed-wire strand, the raised smooth-wire strand and the installation of “goat bars,” in which the two lower fence strands are en-closed in PVC pipe.
They found that pronghorn avoid goat bars, so-named for the pronghorn nickname of speed goat. They were once thought to be an ideal solution but pronghorn preference showed otherwise.
“Maybe our logic of what makes a good modification, wildlife friendly fencing, might not be seen in the same light by the animals themselves,” mused Paul Jones, a senior biologist with the Alberta Conservation Association.
“If we want to promote these to ranchers, to adopt wildlife-friendly fencing guidelines, then we need to start looking at testing to make sure that they are actually functional.”
The ACA, University of Montana and the Nature Conservancy conducted the study and found that raising the bottom barbed-wire strand or raising and replacing it with smooth wire were both favoured by pronghorn.
They also examined the use of clips to fasten the bottom and next-to-bottom wires together so animals could easily pass underneath.
As a quick solution at minimal cost, researchers concluded that installing clips at known antelope fence crossings is useful.
None of the modifications affected fence ability to contain cattle, a vital factor in convincing ranchers to adopt the method.
“That’s the way to look at it,” said Jones.
“Even raising it just to 18 inches, especially if you use smooth wire under the whole fence, if a calf gets out, it’s got now lots of places where it can get back in.”
Jones said there has been good rancher uptake on fence modifications but the preferred method is highly dependent on cost and circumstances.
“We promote both smooth wire and clips and leave it up to the ranchers to decide which ones they want to go with. There’s pros and cons to both, not only price, but with the smooth wire you can put it along the whole fence line so now you’ve created more opportunities for pronghorn to cross.
“Mostly that happens when a rancher is putting up a new fence or has a fence in disrepair … and needs to put up new wire.”
About 350 kilometres of fence in Alberta have now been modified to be antelope-friendly.
TJ Schwanky, wildlife projects facilitator with Alberta Fish and Game, said most of it has taken place on private land in the southeast, but also on provincial and federal property.
Three projects are planned this summer and fall near Manyberries, Writing-On-Stone Provincial Park and Onefour.
“We set the bottom wire at 18 inches but typically in that southeastern part of the province, most ranchers have already done that. The big difference is we’re putting a smooth wire on the bottom versus a barbed wire,” said Schwanky.
Antelope can scrape their backs on barbed wire, causing hair loss, risk of infection and even frostbite in extreme cases.
“We’ve torn down a lot of page wire on some of the old railroad lines and then down on the Onefour research station,” added Schwanky.
“Page wire is a total impediment to antelope movement, so it has really opened up some new corridors for them that they haven’t had for probably 60 or 70 years.”
A core group of volunteers has been doing most of the fence modifications.