Caribou numbers steady in Jasper National park

Jasper’s caribou population estimates have increased from 2007, however threats from human activity and predators continue to leave the iconic species in a threatened state in the National Park.

The news was released recently by Parks Canada as part of the 2007-2008 caribou progress report. The report, authored by Parks Canada biologists Layla Neufeld and Mark Bradley, summarizes survey data, DNA analysis from scat, parasite work, predator/prey kill sites and other information collected on the herds in order to describe the health of caribou in the national park.

One hundred and twenty seven caribou live in  southern Jasper National Park, according to estimates from Parks Canada biologists. The number is up from the estimated 93 caribou thought to live in the park in 2007, but still lower than the 151 caribou thought to live in the park in 2006. While the report notes numbers have been relatively steady over the past six years, caribou numbers are well below the estimated 400 that lived in the park in the 1960s and 1970s.

“Small populations increase the chance for catastrophe,” said Neufeld, explaining that small population size exacerbates pressures from other factors affecting the population. “There has been little change in caribou populations since 2003.”

The recent fluctuations could be attributed to the difficulty in counting caribou, which is done using GPS and VHF technology, helicopters for spotting, scat DNA and other methods. Neufeld said missing one group of caribou in a survey can affect population estimates drastically, as could be the case with the 2007 numbers.

In order to keep track of the caribou, the Park attempts to keep 20 collared caribou in the park in order to keep tabs on the Tonquin, Brazeau and Maligne herds. Currently, 15 caribou have been collared.

The three caribou herds made up the study in the national park; and biologists have collared four caribou in the Brazeau pack, one in the Maligne herd and 13 in the Tonquin herd.

The a La Peche herd, which stretches into the Willmore Wilderness Park land, was not included in the radio collaring data.

“We try to maintain around 20 collared caribou in the park, using Very High Frequency (VHF) collars which are smaller and last longer,” Neufeld said.

The report also focuses on disturbances to the caribou population.

“Most of the focus is on the threats: predator/prey dynamics, predator access, general disturbances, habitat loss and small population size,” Neufeld said. “Caribou require specific things. They evolved with a low predator/prey density, and are sensitive to disturbances.”

Neufeld said there are a number of threats to caribou populations, such as predator prey dynamics, predator access to caribou, stress (cars, hikers, helicopters), habitat loss and small population size.

While some factors are larger than others (habitat loss does not play a large role in the park, Neufeld said) predator access is one of the reasons behind the area closure on Cavell road. Neufeld said in the winter, more forays by humans into caribou habitat make it easier for wolves to access the animals, as they make tracks in the deep snow, leading into caribou territory. Caribou’s main defence against predators is its ability to get into hard to reach places.

The report states that increased elk and deer population in the area are keeping wolf populations at high levels, increasing the likelihood they will prey upon caribou. Based on GPS information, at least four caribou were killed by wolves last winter. That was determined by comparing caribou collaring data with wolf collaring data.

Measures such as wolf culls have been used in other jurisdictions to help protect caribou populations, however a recent study on wolf density through the University of Alberta, co-authored by sustainable resource development large carnivore specialist Nathan Webb discourages such activity in the national parks. More information is needed on bear and wolf predation on caribou, Webb said.

“Uncertainty surrounding the effects of wolf control on populations in the adjacent National Parks remains a concern for some resource groups,” states Webb’s report.

 Public opinion opposes killing wolves as well, Webb’s report said.

Caribou are not the main prey for wolves traditionally, however wolf populations are thought to increase along with the increase in elk and deer populations. That in turn will put more pressure on caribou, the report states.

Increasing pressure on the caribou is the lack of interbreeding between the herds, something that genetic data says used to be more common.

“There used to be good movement between the herds, now the Tonquin is separate,” said Neufeld.

Parks caribou collaring data is also contributing to the Canadian Rockies Woodland Caribou project, which is headed by Byron Weckworth and Nick DeCesare.

Weckworth, a PhD student with the University of Calgary studied predator/prey dynamics in the park this summer. Partnered with colleagues from the University of Montana, Weckworth has been studying wolf, moose and caribou movements through the use of telemetry data to investigate kill sites.

“We investigate where the killings take place, and now we’re retracing the steps of the wolves,” Weckworth said. “The packs take one or two large animals a week. Bigger packs take more animals.”

Weckworth’s work has shown wolves are eating deer, moose and some caribou.

“To understand ungulate systems, you have to understand the predator/prey dynamics,” he said.

Weckworth also said human activity plays a large role by clearcutting forests and building roads.

“Generally, encroachment on habitat occurs through industry and recreation. Not all recreation is bad, but if you get a quad track into caribou territory, it increases the predation by wolves.”

Roads also fragment caribou populations, Weckworth said.

“Caribou are wary to cross roads,” he said.

Weckworth also released information this year that the Mountain caribou appear to be a combination of woodland and tundra caribou, which brings into question the genetic makeup of the woodland caribou. Weckworth hypothesizes that glacial activity split the herd from woodland and tundra caribou.

Researchers are still attempting to understand the story of the caribou, and how they fit into the evolutionary story of Canada, Weckworth said. There are genetic differences between woodland and barren caribou, however there must have been a mixing at some point, creating a hybrid that behaves differently.

While Jasper’s caribou appear to be surviving, as a whole, caribou populations are declining, Weckworth said.

“We’re not too late, but we’re at a pivitol point,” Weckworth said. “We’re not at the point where we’ve gone too far.”