A new scientific study shows recreational trails and roads are giving wolves easy access to critical woodland caribou habitat, where the carnivores are hunting struggling herds.
Mark Hebblewhite, one of the study’s authors, said this is the first study to clearly demonstrate the strong link between trails and the increased chance of wolves crossing paths with caribou.
“This is as smoking a gun as you can ever get that roads and trails, even in national parks, facilitate wolf predation on threatened caribou by increasing the probability that wolves can find and encounter caribou,” said Hebblewhite, a biologist at the University of Montana who has studied caribou for 20 years.
“These results have very important implications for human use management in the national parks, and even bigger implications in the foothills and boreal forests of Alberta where other ‘trails’ like roads and cutlines likely have an even greater impact on caribou habitat security.”
Caribou numbers have been dwindling throughout Alberta for several decades and some scientists believe they could be gone entirely from this province within the next 70 years.
It is now thought that national parks alone will not be able to provide safe haven for caribou, where herds are also experiencing concerning declines.
In Banff, an estimated 25 to 40 caribou a century ago dropped to less than 10 by the mid-1990s. The last four individuals were wiped out in an avalanche north of Lake Louise in the spring of 2009.
The protected federal lands of Jasper National Park are home to an estimated 250 caribou within two different populations – and their numbers are also declining.
The northern A La Peche population is estimated at 150 animals, while the south population, which roams in the Maligne, Tonquin, Jonas Creek and Poboktan Pass areas, is around 100.
That’s down from counts of 450 surveyed in the early 1960s, and based on these trends, scientists predict the south Jasper herd could be completely gone in 40 years without human intervention.
On neighbouring Alberta provincial lands, where there is intensive oil and gas development and forestry activity, most caribou populations have been fragmented and continue to dwindle.
Limited patches of high quality habitat, wolf predation, climate change and direct and indirect effects of human activity, including industrial development, are all likely factors in the decline.
Researchers for this most recent study – published in the the Journal of Applied Ecology – analyzed data from GPS radio-collars from 35 adult caribou and 37 wolves from 11 different packs in Banff and Jasper over the last 10 years.
Eight of the 11 packs – or 28 of 37 wolves – had home ranges that overlapped with caribou territory. Twenty-three radio-collared caribou died, of which at least 12 were killed by wolves.
Jesse Whittington, a Parks Canada biologist who led the study, said when caribou hang out near roads or trails, they have a 95 per cent chance they will encounter wolves during the year.
On the other hand, he said, if they are far from roads and trails, caribou only have a 65 per cent chance of crossing paths with wolves.
“When you’re travelling in the backcountry, you’ll often find that wolves use these trails like highways and the trails are covered with wolf tracks,” said Whittington.
“Wolves are incredibly smart animals. The trails provide an easy route across their territory, which makes a big difference when they are covering 30 kilometres a day.”
Researchers were also interested in knowing how wolf selection for trails changes through the year and how it changes with increasing elevation.
They discovered wolves prefer low elevations, especially during winter and spring, but their preference to travel on roads and trails increases the higher up they go.
The risk of caribou encountering wolves was highest during the summer and autumn, when wolves spent the most time at higher elevations, the study found. Most wolf-caused mortalities occurred during spring and summer.
“We found in the summer time wolves showed just a slight selection for roads and trails because forests are open and it’s pretty easy to travel anywhere; however, wolf selection for trails increased with elevation and more rugged topography,” said Whittington.
“In winter, wolf selection for trails also increased. In early and mid-winter, deep unconsolidated snows make travel off-trail difficult for wolves and that is why packed ski and snowmobile trails are so attractive to wolves.”
Whittington said the biggest concern on Parks Canada-managed land is snow-packed winter trails that allow wolves to travel into caribou range.
“In winter, when we punch a trail up a long linear valley, we’ll often find that wolves cruise up that trail within a week,” he said.
The study concluded that Banff National Park experienced three times higher encounter rates between wolves and caribou than Jasper.
Although Banff’s caribou population was wiped out, the small herd had traditionally spent much of its time in the upper Siffleur and Pipestone valleys.
And given the possibility of reintroducing a herd back into Banff, Whittington said the Pipestone and Upper Siffleur Valleys are the main valleys of concern for Banff National Park.
He said they are long valleys with deep snows and historically little wolf activity, and recent winter monitoring shows these valleys were used only twice by people and once by wolves.
“With these low levels of use, caribou in Banff National Park would appear to be relatively safe from wolves during winters,” said Whittington.
Whittington said this study is just one of many being used to examine the feasibility of caribou translocations into Banff and/or Jasper.
Until a decision is made on whether to translocate caribou to Banff or Jasper or both national parks, Whittington said Parks Canada is focusing efforts on developing a captive rearing program.
“We are working out the details in terms of where we will obtain caribou, how many caribou we will require, what time of year we should release them and how much the program will cost,” he said.
“When we have caribou ready for translocation, we will evaluate all analyses to determine where translocations will have the highest probability of success and where they will have the greatest conservation value amongst the mountain parks.”
Hebblewhite said Parks Canada is working on human use issues in caribou range in Jasper, noting a part-time winter closure of a road to prevent human access into the Tonquin Valley.
“Parks is taking the right steps to reduce winter use in Jasper and I hope this research gives them the ammunition they need to be able to back that up,” he said.
Dave Ealey, a spokesman for Alberta Sustainable Resource Development, said there’s no real surprises in the study.
“We know the importance of reducing any new linear features and recovering old features, and those are two integral parts of our caribou policy,” he said.
“We’ve recognized habitat issues and that’s certainly part of what we’re trying to address with the caribou policy and our work we can do with various industry in specific caribou ranges.”
Meanwhile, last month the federal court ordered the federal government to reconsider its position on emergency protection for woodland caribou in northeastern Alberta.
In its decision, the court also noted a recovery strategy for the woodland caribou is four years overdue and gave Environment Minister Peter Kent a Sept. 1 deadline to release a draft.
The court heard that some herds have declined by more than 70 per cent in the last 15 years. In addition, scientific evidence indicates that oilsands development contributes to caribou declines, yet as of July 2010, there were 34 current or approved oilsands projects within caribou range.
On a larger scale, woodland caribou are struggling throughout North America and this latest study has broad implications for land managers.
“These results show that if you create a trail, road or other linear feature into caribou range, it will increase caribou risk of predation,” said Whittington
“By the same token, the removal of trails or roads from caribou range should increase caribou chance of survival.”
