For most people, locals and visitors alike, spotting a grizzly bear in a mountain park setting may be the highlight of a visit, a hike, a summer, possibly of a lifetime.
As an iconic symbol, a large, powerful grizzly speaks to illustrating the wild in wilderness, nature’s grandeur and maybe, deep down, a fear within us.
Millions of people travel to mountain national parks and consider a holiday a complete success if they spot a bear, or, better yet, maybe get a photo worth sharing among friends and family when they get home.
Imagine, then, or be jealous of, wildlife experts poring through many photos of wildlife – as in, thousands – over a vast expanse of Alberta and B.C. with an eye to viewing grizzlies in particular in their natural setting.
That’s the situation Parks Canada’s wildlife ecologist Jesse Whittington, along with University of Montana’s Mark Hebblewhite and PhD student Robin Steenweg found themselves in while working on a paper (Camera-based occupancy monitoring at large scales: Power to detect trends in grizzly bears across the Canadian Rockies) for the September 2016 issue of Biological Conservation.
In publishing their paper, the three viewed images from about 275 remote cameras; 200 general use cameras and more than 75 project-specific cameras from Waterton to Jasper and including Banff, Kootenay and Yoho parks. Cameras were positioned on over and under passes, at grizzly rubbing trees and in areas where constrictions in the landscape leave few options for movement.
A minimum of 60 cameras are needed, according to Steenweg’s research, to collect suitable numbers of photos for study.
Remote cameras, triggered with an infrared beam and with the ability to store digital images, have come a long way since they featured roll film and actual cables animals had to stumble into to trigger them.
“And squirrels would often chew through those cable,” said Whittington, “which meant you’d check a camera some time after placing it, only to find no photos in it.
“A lot of people are using remote cameras for exploring the world and this started in 2011 with Robin and Mark.”
For the Biological Conservation paper, images from 2012 were perused. “Project-specific cameras were placed at Texas gates and in spots where we wanted to see how they approach fences. We found you can detect changes in grizzly range by using the photos and we’ve found that grizzly numbers are at about the same level as in 2006-08 when DNA testing was done.”
The remote cameras cost about $600 per unit, are very reliable and have batteries which, when taking low-resolution photos, can last a full year. As part of the study, a camera was placed in most bears’ 10 by 10-kilometre range, and four in each female’s range.
“Females are the drivers of the grizzly population,” said Whittington. “We wanted photos of grizzlies in general, but also of grizzly family groups and females with young of the year.
“For grizzlies, the population is stable, which is great news. We were hopeful the population would be stable, but you don’t know until you have the data.”
Along with grizzlies, of course, the cameras captured images of wolves, wolverine, elk, moose, deer, etc.
“It’s so neat, so compelling to see these images,” said Whittington. “Often when I’m hiking, I see some bears, or not. You can never be sure you’ll see one. But with the cameras we saw several males and females on the Fairholme Bench in breeding season, for example. Cameras are now the bread and butter for monitoring all wildlife in parks.
“They’re also vital for studying climate change, along with effects of fire, snow and vegetation changes.”
Generally, grizzlies can’t be differentiated from each other, but Whittington and his partners did have the opportunity to identify individual bears that were collared for a Parks/CP Rail study, adding data for that project.
Among the surprises noted are an increase in white tail deer numbers, an increase in wolves and a decline in elk. And the fact that grizzlies are using under and overpasses, said Whittington, “was good to see. It shows that what we do is helping support grizzly populations.”
In Alberta, the grizzly has a threatened status, but Whittington is optimistic that the bears’ number are the same as during the 2006-08 DNA test, which showed them at 14 or 15 per thousand square kilometres.
The scale of the work is evident by the fact that, since 2011, more than 11 million photos have been classified. Only Parks staff handle the photos and, due to concerns for public privacy, all human use photos are deleted (ie. photos where hikers, bikers, equestrian riders, etc. trigger the cameras).
“The photos are such an important tool, and we don’t want anyone to have privacy concerns,” he said.
“With the cameras, we’ve seen everything from snowshoe hares to moose, to bears and wolverine. It’s an awesome thing because the cameras are invisible to wildlife so we see them in their natural state.
“And using them is important because we’re still considering caribou re-introduction. We found wolverines prefer the parks and they (photos) let us look at wolf density; wolves are a strong driver in elk migration patterns.”
A side benefit of monitoring wildlife with cameras is that, “they’ve really fostered collaboration among researchers around the world,” said Whittington. “For example, researchers at Virginia Tech are looking at images from the Rocky Mountains.”
By way of research, key components are that photos are gathered from known locations, are date and time stamped – all of which help quantify efforts.
Remotely triggered cameras first saw use in 1999, said Whittington, and as technology has improved, so have analytical techniques for using the photos.
“They’re a non-invasive way to study wildlife,” he said. “They’re covert and camouflaged, have no flash, and there’s no sound. We place them three to five metres off trails and they have infrared triggers. One triggering can make for five photos, so you can often most animals in a family group.
“We had more than 600 grizzly detections with the cameras and it’s amazing to see them scratching and rubbing, playing and struggling through snow.”
An abstract from the Camera-based occupancy monitoring at large scales: Power to detect trends in grizzly bears across the Canadian Rockies paper states monitoring carnivores is critical for conservation, yet challenging because they are rare and elusive.
Few methods exist for monitoring wide-ranging species over large spatial and sufficiently long temporal scales to detect trends. Remote cameras are an emerging technology for monitoring large carnivores around the world because of their low cost, non-invasive methodology, and their ability to capture pictures of species of concern that are difficult to monitor.
Here we test camera-based occupancy models as a method to monitor changes in occupancy of a threatened species, grizzly bears (Ursus arctos), at large landscape scales, across five Canadian national parks, about 21,000 square kilometres.
… As hypothesized, statistical power increased with the number of cameras and with the number of days deployed.
