This week I look at new research that investigates wolverine in the mountain west and the challenges they are having with connectivity with other populations further south. It’s also time for tick talk with the tick season upon us and increased vigilance as the black-legged tick expands its range in Alberta.
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Wolverines at Risk in the Mountain West
Over the past few years, I’ve talked at length of the challenges of trying to balance tourism with conservation. Much of the conversation revolves around more visible species like black and grizzly bears, along with wolves. These are the carnivores that have made the headlines, unfortunately for the wrong reasons in many cases.
Throughout the major tourism corridors in the mountains, it is harder and harder to protect the movement corridors that bears and wolves need to hunt, disperse, reproduce, and raise their young.
One thing that is often overlooked is that these are some of the more flexible animals on the landscape. We talk about them because they are the neighbours that we are most likely to see in the landscape. Black and grizzly bears are the big iconic poster child of connectivity. Bears like the Boss, grizzly 148, 64 and 72 were all treasured mountain icons. If you haven’t checked out last weeks episode, I talk at length about each of these particular bears. Check it out at MountainNaturePodcast.com/ep076. All too often though, we fail to talk about the ghosts, those animals rarely seen but also critical to a functioning ecosystem. One of these barometers of ecosystem health is the wolverine. For most tourists to the mountains, wolverine are more myth than reality. Some youngsters only think of Wolverine as a Marvel character and have no idea that the character is inspired by a real animal.
Surprisingly, even as I write this, the grammar checker on my computer keeps correcting me to refer to Wolverine as an individual instead of as an important member of the weasel family.
I remember my first sighting of a wolverine. To put it into context, wolverine prefer the remotest of mountain landscapes. They avoid people, development, and trails. They don’t hang around townsites and they don’t spend time near roads or trails.
So where did I meet my first wolverine? I was mountain biking along the trails of the Canmore Nordic Centre. This is an extremely unlikely place to encounter a wolverine. It’s also funny how your brain reacts when you first encounter an animal that you’ve never seen. I saw this thing that looked like a large bear cub but it also had a long tail.
As my brain rattled through possible identifications, it stood up on it’s back legs to get a good whiff of my sweaty scent. Right away, I noticed the fluid spine of the weasel family and realized my luck. Spotting a wolf is the equivalent of winning the wildlife lottery. Spotting a wolverine is like winning ten lotteries in a row. It looked at me for a few moments and then dropped back down on all fours and wandered off a bit.
I noticed the blonde patch that runs along the sides of wolverine that give them the nickname “skunk bear”. It ran about 10 metres and stood up once more before dropping down and disappearing. To say I was excited was an understatement. While wolverine have a reputation for being fierce, they don’t seek out conflict. It was just making sure that I wasn’t a threat, and then it continued on its way.
When I finished my ride I made sure to stop in at the visitor centre to report the sighting. Despite my insistence that a wolverine was an important sighting, the attendant didn’t make note of the encounter. A few years later, I bumped into biologist Jake Herrerro who did a lot of the research on the wildlife corridor running through the Bow River valley. After mentioning the encounter, he was shocked. It was the one hole in his research and he mentioned it was the only sighting on that primary wildlife corridor.
This really goes to show the importance of documenting and reporting important wildlife encounters. While this was the unlikeliest of places to meet a wolverine, it was also the most likely. As much as they like remote locations, occasionally the landscape traps them into a narrow pinch point as they cross through a wildlife corridor.
Wolverine are especially rare. Recent research in Banff National Park is looking into how connectivity is one of the principal challenges to maintaining wolverine populations.
In the early days of conservation, protecting wildlife was largely focused on protecting habitat. If we can create enough parks than we can protect all the animals that live in them. These early conservationists didn’t understand the importance of connectivity. A park without connectivity is a prison.
Research conducted in the past 20 years has shown that carnivores like wolverine cover vast territories. While individuals may hold a territory for years, they need to reproduce, and their young need to disperse. Every island of habitat needs to be connected to other islands of suitable habitat.
The more reclusive the animal, the larger those islands need to be; and there are few animals more reclusive than wolverine.
One of the great conservations stories in Banff over the past 30 years has been the fencing of the highway and the six overpasses and 38 underpasses that have been incorporated specifically to allow animals to freely move back and forth across the Trans Canada highway.
Recent studies showed that in Banff, Yoho, and Kootenay National Parks there were 49 wolverines, of which 20 were female. That makes space for only 1.5 females and 1.7 male wolverines for every 1,000 square kilometres in the mountain parks. I often talk about the large range of grizzly bears in this podcast but the range of a single wolverine would be the equivalent to that of three grizzlies. Their densities are very low on the landscape.
If you travel a little further north towards the Willmore wilderness, studies show a density of 6.8 wolverines per 1,000 square kilometres. What’s that? You’ve never heard of the Willmore Wilderness? Well, that’s the point. Remote landscapes support much higher densities of wolverine.
While the fencing and crossing structures have been a success for grizzly and black bears, along with hoofed animals, the fences pose a challenge for wolverine.
Banff’s crossing structures are located based on movement patterns of the more visible animals like bears and wolves. Wolverine don’t follow trails. They wander across contour lines and ignore natural terrain funnels. This means that when they encounter the highway, they often encounter the fence, not the over or underpass. This is particularly challenging for female wolverine.
South of the mountain national parks, connectivity challenges only get worse. Southwest Alberta and southeastern British Columbia have seen large drops in wolverine densities and high rates of trapping in the area have only accentuated these losses.
Wolverine from the mountain parks also are finding it more difficult and more dangerous to disperse south towards the U.S., border. As landscapes become fragmented by development, roads, and trails, wolverine are being squeezed out. This makes it very difficult for northern individuals to migrate into areas further south.
At the same time, warming climates are limiting winter snowpacks. Without a deep, subalpine and alpine snowpack, wolverine can’t reproduce. In episode 73, I talk about how critical deep snowpacks are to the reproductive success of wolverine.
These recent studies show that connectivity between our northern populations is being slowly cut off from northern U. S. populations. At the same time, reduced snowpacks in the south are also reducing reproductive successes south of the border.
Another wolverine study is taking place in British Columbia’s northern Columbia Mountains. This is a fascinating study that has found innovative ways to get a better idea of individual wolverine’s use of the landscape.
This project uses automated wildlife cameras, bait sites, hair traps, and special construction to make wolverine pose perfectly for the camera before getting rewarded with a beaver carcass.
In 2017, University of Calgary PhD candidate Mirjam Barrueto began a study designed to focus specifically on female wolverine. In any wildlife population, females are the reproductive engine and understanding them helps to get a much more detailed understanding of the overall population.
As part of this study, locations within the massive territories of wolverine were baited with beaver to attract them within range of wildlife cameras. Lead researcher Mirjam Barrueto designed an ingenious way to gather as much possible data on her cameras.
She used beaver carcasses as bait, but they were kept largely out of reach of the wolverine. To get to the carcass, the wolverine had to climb a wooden frame, crawl through a barbed wire loop where they would leave some hair behind for DNA profiling.
After they negotiated the loop, a vertical frame forced the wolverine to climb up to a point where it could barely touch the beaver. To access the beaver, it had to stretch its entire torso wide for the camera. This gave Barrueto the money shot.
The patterns of blonde and dark patches on the chest of a wolverine can be used to identify individual animals, and with their back legs spread she could determine the sex. Perhaps the most exciting thing this wolverine climbing gym did was it gave her a clear view of its chest and so she could see which females were lactating.
DNA doesn’t tell researchers about which individuals are the most important breeding individuals in a population. This ingenious design accomplished all of this – all under the steady gaze of wildlife cameras.
It’s studies like this that keep me looking for more ingenious research projects. Each new generation of researcher brings new and innovative tools that enable new discoveries and continue to expand our knowledge of the wildlife and culture of the mountain west.
Next up, it’s time to talk ticks
Ticks and Lyme Disease in the Central Rockies
Well, it’s that time of year again; the time of year when a day playing in the mountains is not complete until you complete a good tick check. I like to think of this as a social way to wrap up a good day in the mountains. This is particularly important if you’re in habitat frequented by bighorn sheep and other large animals that are also a favourite food for the Rocky Mountain wood tick.
Rocky Mountain wood ticks, the main species that impacts humans in the mountains of the Central Rockies, has a three-stage life-cycle. It is not a carrier of Lyme Disease, although it can carry the bacteria that causes Rocky Mountain spotted fever.
Each of the three stages of a rocky mountain wood tick requires a different host. This differs from moose ticks which can spend their entire life on a single moose, with a single moose hosting thousands of ticks at a single time. During warm winters, tick numbers can explode so much that a single moose might host as many as 140,000 ticks. In extreme cases, heavily infested moose don’t survive winter. If you’d like to know more about moose ticks, check out episode 16 at MountainNaturePodcast.com/ep016.
Don’t worry about a tick falling on you from a tree. It simply doesn’t happen. If you catch a wood tick, you catch it from low vegetation like grass. Adult ticks when they’re questing for a blood meal climb to the tops of grassy plants and then they hold on with their back two legs. The other six legs spread out like tiny grappling hooks waiting for any warm-blooded medium to a large mammal to happen by.
All it takes is for you to brush past those grasses, and presto, you have a new hitchhiker. They are very patient. An adult wood tick can wait as long as 600-days for an unwary host to wander past.
At this time of year, adult ticks are actively looking for a blood meal. Unlike mosquitoes, where only the females bite, both male and female wood ticks need blood meals. Males only take a small amount of blood to stimulate the production of sperm before mating with a female. Females take a much larger quantity of blood and will feed for between 3 and 11 days before dropping off.
She also grows massively large during this time, making wood ticks quite easy to find if you miss them at the beginning. By the time they get almost as big as a grape, you’re sure to find them. Male ticks mate with numerous female ticks while the females are still feeding. After a blood meal and mating, it’s time for laying eggs…lots and lots of eggs.
Wood ticks lay their eggs in damp vegetation during May and June. A single female can lay as many as 6,000 eggs over the course of 10 days to a month. The eggs hatch into larval ticks in early summer and begin looking for their first host, usually a small mammal like a vole, chipmunk or squirrel. These tiniest of wood ticks usually stick to smaller animals and tend to leave people and pets alone. After all, this is just the first stage in their growth in size and appetite.
They can wait more than 100 days for the right host to come along, and after feeding for a few days to a week, they drop off the host. Over the course of a few weeks, they’ll moult and emerge as nymphs. Progressively larger in size, they still look for a small rodent to feed on for their second meal.
After another long feed, they’ll moult into their largest adult stage in a few weeks. These are the wood ticks that are a threat to humans and pets. Again, at this point, I’m talking about the Rocky Mountain wood tick, the tick that is prevalent in the mountains. It is not capable of spreading Lyme Disease and so the risk of this disease is very low. That doesn’t mean that these ticks don’t transmit disease. They can carry both Rocky Mountain Spotted Fever and Tularemia. Cases of both of these diseases are very rare but they are a possibility.
The tick that is responsible for transmitting Lyme Disease is the black-legged tick. Currently, black-legged ticks aren’t found in the mountain regions – yet. Over the past few decades, black-legged ticks have expanded their range extensively and are now found in most areas of the Alberta prairies. Areas around Calgary and Edmonton are now known to have black-legged ticks.
In a 2018 Edmonton Journal article, University of Alberta entomologist Janet Sperling gave a dire warning. She warned that 1 in 5 people bitten by black-legged ticks could contract Lyme disease. As a board member of the Canadian Lyme Disease Foundation, she would know.
While the life-cycle of black-legged ticks is similar to that of the Rocky Mountain wood tick, there are some important differences. Since only adult wood ticks attack people, and they are pretty large in size – around 3.2 mm or 1/8″ in length before feeding – they’re fairly easy to spot if you do a good tick check.
While adult Black-legged ticks actively seek out larger mammals for their final blood meal before laying eggs, on occasion, even the much smaller nymph-stage ticks will also take advantage of a human to feed. These ticks are tiny, around 1.5 mm in length making them very easy to miss as they crawl onto your body looking for a good spot to feed.
The incidence of Lyme Disease is increasing on the prairies due to two main reasons:
- with warming climates ticks, like many other species, are rapidly expanding their range and
- With warmer winters, more ticks are able to survive until spring in order to mate. The end result is that we now have far more ticks crawling around than we used to.
So how worried should we be as we play in the mountains? The simple answer is careful, but not to worry too much. The tick season in the mountains is usually a spring thing. Ticks are already being found and this will continue into June. As the heat of summer arrives, the number of ticks tends to decrease.
Currently, the Rocky Mountain wood tick doesn’t carry Lyme Disease and the black-legged tick isn’t found here. That being said, in the eastern slopes we’re right at the battlefront of a rapidly expanding range for this destructive tick. I would expect hikers along the foothills to be the first to see black-legged ticks moving upslope.
One thing we can all do is to save any tick that we find and submit it to the Alberta submit-a-tick program. This important program collects ticks submitted, identifies them, and then tests them for a disease. This has been a very effective program in terms of helping experts both map the range expansions of the black-legged tick and to keep tabs on the potential for Lyme disease and Rocky Mountain spotted fever.
What should you do to prevent tick-borne diseases?
One of the most important aspects of ticks is that they’re lazy and very picky. Once they grab onto a potential host, they want to climb on skin and not fabric. If you’re in an area that has a high potential for ticks, like an area frequented by bighorn sheep, tucking your pants into your socks can help prevent hitchhikers. Wood ticks will often only crawl a short distance up your leg before dropping off and waiting for a more accommodating host.
Tight-fitting clothes also help keep them on the outside rather than giving them the ability to find the perfect warm, moist feeding site. Insect repellent with DEET can also deter them.
Light coloured clothing also makes a crawling tick stand out much more starkly against the fabric.
If you’re in tick country, walk towards the middle of the trail. This helps minimize your contact with low grasses and plants that may hide an eight-legged hitchhiker.
Once you’re finished your walk or hike, take turns checking each other for ticks. Running a fine-tooth comb through your hair can also catch the little guys and gals. Ticks usually spend several hours exploring before they find the perfect spot. This pickiness usually gives you a good chance to find them long before they actually embed and begin to feed.
Always remember that you can’t contract a disease by a tick that is simply crawling on you. Disease transmission only occurs through their saliva when they begin to feed. The longer they feed, the higher the likelihood they will transmit the disease bacteria to you.
Removing a tick isn’t difficult. If you’re an avid outdoors person, be sure to keep a pair of tick tweezers in your pack. If you find an embedded tick, firmly grab the entire tick and slowly pull it out. Be sure to submit it to the submit-a-tick program as well.
If the tick has only been feeding briefly, you’re still fine. According to the American National Institute of Health, It takes several days of feeding before Lyme disease is transmitted. It’s also important to remember that a tick only gets infected by biting an infected host. It then carries the infection to its next blood meal.
This means that as warming climates result in higher populations of ticks infecting more people than the incidence of ticks carrying the disease will also go up.
Enjoy your time in the mountains. Think about ticks before you go out, dress to reduce the chance of infection, and then check for them when you finish your outing. If you do find a tick, submit it for study so that it can help us all stay safer and more informed. This is one of the best opportunities for the average hiker to help inform the medical community. The range, prevalence, and infection rates of black-legged ticks are changing rapidly. Every tick submitted is another piece of data helping us all stay safe.