Saturday, May 28, 2016

Balancing the issue of predator and the prey

Wolf attack an elk on an overpass in Banff National Park.
Wolf attack an elk on an overpass in Banff National Park.
Christopher James Martin/For The Globe and Mail 

Predator-culling programs, aimed to slow the decline of big game animals, are drawing international condemnation , writes Mark Hume
 
From his ranch near Ta Ta Creek in southeast British Columbia, Bob Jamieson looks out at a wild and dramatic landscape that is gradually emptying of big game animals. 

The caribou are nearly extinct, and the great herds of elk that once ranged across the Rocky Mountains, from B.C.’s Kootenay River valley to the Alberta foothills, are dwindling. Moose are in decline too, as they are across most of western North America. 

Mr. Jamieson, a systems ecologist and environmental consultant, says the loss of those species is “a very complex and difficult problem” that involves habitat loss, landscape fragmentation by development – and the role of “a suite of predators.” 

It is that last factor, he says, that presents wildlife managers with one of their greatest challenges, because controlling predators usually means killing animals such as wolves. In Saskatchewan and Manitoba, wolf control is done through liberal hunting limits or by paying bounties to trappers; those are low-profile programs that draw little public criticism, but they also have limited success. In British Columbia and Alberta, however, controversial culls are under way in which government hunters track radio-collared wolves and shoot whole packs from aircraft. 

British Columbia and Alberta launched their current programs to save herds of endangered caribou, but the culls have generated international condemnation, with pop star Miley Cyrus and global wildlife crusader Paul Watson among those joining in the attacks. 

Mr. Jamieson said the systematic killing of wolves will always be controversial, but there is no getting away from the fact that they – and other predators – play a key role in the decline of species such as caribou, elk and moose. 

“I’m here in a dry valley south of Banff. I’m looking out at the west slope of the Rockies … we have a lot of elk here, but we have lost two entire elk herds … and they are gone from valleys where there is no human habitation,” he said. “There’s nowhere for these animals to go to get away from the wolves.”
Killing wolves will not aid caribou recovery nor prevent their continued decline.
Dr. Paul Paquet, Raincoast Conservation Foundation
If you drive through the Kootenay River valley along the west slope of the Rockies, and go up through Banff National Park, you will see elk browsing along the roadsides and standing like regal tourism monuments. 

But Mr. Jamieson, who has lived in the area for more than 40 years, says the elk are along the roads for a reason – hoping to escape predators – and their high visibility gives a false impression that there are lots of game animals around. 

In fact, he says, game species have largely vanished from the back country where they used to be in great numbers. “It’s primarily elk [that have gone], but there are relatively few moose and very few mule deer left in those valleys,” Mr. Jamieson said. 

Valleys he used to hike during the fall rut to listen to male elk bugling are now largely silent – except for the howl of wolves. And where elk are found, they are in decline. One herd he’s monitoring has gone from 1,000 animals down to 200 in a few years. 

British Columbia’s South Selkirk caribou population has suffered worse and is down to just 14 caribou, a number so alarmingly low it triggered British Columbia’s wolf cull last year.
Critics of the cull, such as Dr. Paul Paquet of the Raincoast Conservation Foundation, say the real problem facing caribou is habitat loss, not predation. 

“Wolves prey on caribou today as they always have, but the role of wolves in the ongoing decline of mountain and boreal caribou is a symptom of eroded and lost caribou habitat, not an underlying cause,” he has written. “Killing wolves will not aid caribou recovery nor prevent their continued decline. Other predators (for example cougars and grizzlies), roaded and fragmented habitat, food limitations and human intrusion into key habitat will perpetuate caribou decline.” 

The cull is seen by some as misguided wildlife management at best, or evil at worst. Ian McAllister, whose organization, Pacific Wild, has been leading a campaign to stop the cull characterizes it as “the persecution of wolves,” not wildlife management. 

Mr. McAllister says wolves are being used as a “scapegoat” for other problems. But Mr. Jamieson says the real problem with the wolf cull is that it might not be going far enough. “The issue is not wolves, it’s the combination of wolves, grizzly bears, black bears and cougars … the prey species can’t handle the combined impact of those four animals,” he said. “A lot of people [blame] habitat problems because they don’t want wrap their head around the predator issue.”
Wolf attack an elk on an overpass in Banff National Park.
Wolf attack an elk on an overpass in Banff National Park.
Christopher James Martin/For The Globe and Mail 

Mr. Jamieson said a wildlife conference on predator-prey systems, which drew leading experts to Revelstoke, B.C., in April, made it clear that grizzly and black bears, wolves and cougars are all preying heavily on elk calves, and it is reasonable to assume young caribou, moose and deer are also being impacted. “There are three different studies on elk now that show between the four predators, that 60 to 70 per cent of the elk calves are dying before they even get through their first winter,” said Mr. Jamieson. 

Studies in Yellowstone National Park have found that after wolves were reintroduced in 1995, the elk population fell from over 19,000 to about 6,000 by 2007.

Research by wildlife biologist Shannon Barber-Meyer of the U.S. Geological Survey found grizzly bears, black bears and wolves, in that order, were the main predators.

Mr. Jamieson said while wolf predation has long been recognized as a problem, recent research by David Vales of the Muckleshoot Indian Tribe Wildlife Program has shown cougars can also drive down game populations. 

In an interview, Mr. Vales explained how the Muckleshoot, in Washington State, restored elk populations by culling cougars. “We began radio-marking adult cow elk and calves in 1998,” he said. “By going in on the mortalities, we [identified] the cause.” His study found that 70 per cent of the elk were killed by cougars. “I’ve always done a lot of modelling of elk-wolf systems in Yellowstone and around Glacier [National Park] in Montana, so I had some idea of the impact individual predators might have. But I was really surprised how much cougars can impact an elk herd,” he said. “It’s amazing, when we are out marking calves, how many cats have come to check us out while we’ve got a calf in hand and it’s screaming. We look behind us and there’s a cougar there.”

The study found cougars were killing about 50 ungulates (primarily elk, but also some deer) a year. One cat killed 73.

With that data in hand, the Muckleshoot began hunting cougars. It took five years to normalize the ratio of cougars to elk, because as cougars were shot, new cougars kept migrating into the valleys to prey on the elk. (Research shows that a similar thing happens when wolves are culled; new packs move in.) 

But Mr. Vales said once the number of cougars dropped, the elk population rebounded dramatically.
“I don’t think [predator control] is a panacea in all cases, but in some cases it works really well,” Mr. Vales said. 

Critics of predator control argue that if nature is allowed to follow its course, a state of balance will be found, with predators increasing or decreasing in sync with their prey. “That’s not really what happens,” Mr. Vales said. “With the natural balance, cougars are going to wipe out the elk … That’s sort of like what’s happening with the wolves [in B.C. and Alberta].”