If you, like me, grew up in the Yukon, bear awareness training has been part of your life since you were a wee child. Some combination of videos and booklets have let you know that yes, bears sure are out there and this is what you should do in response to a variety of bear encounters. But here’s the thing, just how aware of bears are you really? The Yukon is renowned for its bears but there are actually some gaps in our bear knowledge, particularly when it comes to just how many bears are actually out there! Population size is important for studying everything from the spatial distribution to the health of a species, but there hasn’t been a bear survey in the Yukon since the 1980s. Unless the Yukon bears are both immortal and not having babies, that information is a touch outdated.
Lucile Fressigné is leading an on-going study that seeks to fill in this gap in bear population knowledge. Starting in 2020, she started a community-based project to survey the Yukon’s bear populations in a creative way that also doesn’t bother the local bears: by collecting their scat! That’s right, Operation Ursus Research using Scat (OURS) is aimed at updating and providing a scientifically reliable estimate of the population size of Yukon bear species using a non-invasive DNA-based method that relies on scat samples. Last year, the study focused on collecting samples in the Mount Lorne, Marsh Lake, Tagish, and Fish Lake areas of the territory. Fressigné offers Yukon residents the opportunity to be part of this project and help build this sample collection by offering free collection kits that can be dropped off at community centres in the study areas. Yes, you too can take part in bear science!
OURS aims to get an estimate on both grizzly (Ursus arctos) and black bear (Ursus americanus) populations. These bears tend to be especially difficult to inventory and monitor as a low number of bears will occur over a large home range and they tend to be avoidant by nature. Grizzlies are the largest of the two and are very distinctive with their dished face profile and defined shoulder hump. They are often referred to as “brown bears” but their colours can range from white to almost black. They most commonly have “grizzled fur”: a deep brown with lighter ends. Apparently, no one told them that frosted tips went out of style in the early 2000s.
In 2018, grizzlies in western Canada were designated as a species of special concern. This means that they are a species that does not meet the criteria of an endangered or threatened species but is particularly vulnerable, and could easily become endangered, threatened, or extirpated. This rapid loss of population could happen from a variety of factors such as restricted distribution, low or declining numbers, and/or specialized habitat needs or limits. One of the many benefits of having a population estimation for grizzly bears is that it can help provide a basis for a proactive conservation strategy.
Black bears, as the name would suggest, are most often black but can also be blonde, grey, cinnamon, and brown (in which case, the name is very misleading). They have a straight face profile and lack the shoulder hump present in grizzlies. They also lack the species of special concern status but this doesn’t necessarily mean there are more black bears in the Yukon because, like grizzlies, the last time there was a black bear population estimate was in the 90s. Without an updated population estimate, we really don’t know if we should be concerned about them as well.
At first blush, scat analysis might not seem like the most appealing method for studying bear populations but there are a lot of advantages to this method. First of all, it’s incredibly non-invasive when compared with methods like radio collaring. In order to get a collar on a bear, they have to be tranquilized which can result in the injury or even death of the bear (bummer!). The injection site can get infected, the radio collar can get snagged, and there’s a lag between when the dart hits the bear and when the tranquiliser takes effect. During this lag time, bears can run out into a body of water where they can’t be recovered because ursine lifeguards are not a thing.
Hair snags are another non-invasive method for population estimations. This is the most common method of population analysis and it’s done by placing a tantalizing lure near a string of barbed wire. When an animal comes for the lure, they leave a cheeky tuft of hair behind. However, scat analysis doesn’t need a lure/barbed wire setup, you can find it everywhere bears dwell, and it is very easy to identify whereas hair tufts can be tricky to spot. Odds are, if you spend some time in the woods, you’ve come across them before. And believe it or not, there is a ton of information to be gained from analysing bear body waste!
Because scat is found wherever the bear decided to leave it behind, it tells you where and generally when the bear has been so it’s very useful for identifying bear habitats. The DNA analysis technique used on these scat samples is called Genotyping in Thousands by Sequencing (GT-seq). This method can extract information regarding the species, sex, and individual identity of the bear. Knowing this poop-extracted bear information can help scientists track the movement and migration of individual bears as well as trends in bear parentage! Scat also contains cortisol (the stress hormone) which can be used to monitor the relative stress levels of the local bear populations. This can be really important for bear conservation because it can tell us whether bears in certain areas are experiencing more stress than others (are bears living by highways more stressed than those that don’t, for example).
We are generally aware of what bears are eating but scat analysis can give us specific statistics regarding how often and how much bears are consuming of different foods. It also helps chart changes in diet. If one food is present one year and absent the next, this might indicate environmental changes that made this food source inaccessible. OURS can also see how bears are affecting their food sources in turn. As part of this project, Fressigné is partnered with the Kwanlin Dün First Nation who are interested in how or if bear predation is affecting the declining moose population in the Fish Lake area.
The goal of the first season of research was to test the community-based sampling method and generally gauge the public’s interest in the project. It was an opportunity to implement new genetic technology on the collected samples and to test whether the scat collection methodology would yield enough useable DNA. It also aimed to identify the presence and distribution of bears in the sampling areas. Moving into the second season of sampling, OURS is going to adopt a more rigorous sampling method by hiring students to run survey transects in the study area and by partnering with more First Nations and groups that are involved in traveling and exploring through the Yukon wilderness. This includes hunters and trappers, tourism companies, mining companies, summer camps, schools, and very lost tourists. Just kidding on the last one, being a tourist is both dangerous and illegal at the moment.
The OURS project is primarily about providing a population estimate but it’s more than just a bear abacus. Studying the genetic markers in bear scat reveals information about the genetic diversity in bear populations. This work also helps emphasise how important it is to maintain this diversity in order to keep these vulnerable apex species healthy and stable. The groovy analysis from these scat samples will also provide tons of info about bear stress levels, parentage, and the trends and impacts of bear predation. Who knew poo could be so educational?
The project is important for future bear conservation efforts and not just because it gives us an approximate bear count. This study can be used to monitor the impact of climate change on bear behavior and population trends. Continued bear scat surveys can also reveal critical/preferential habitats for bears, and lead to the restoration of these habitats or the creation of protected areas that would minimize human/bear conflicts. Which is great because I don’t know about you, but I don’t want to fight a bear. But in all seriousness, these types of conflicts tend to end badly for the bears so it’s best if they can be mitigated or avoided entirely.
As you can see, there are a lot of benefits to the non-invasive, cost effective, kind of smelly, and highly informative research method of scat sampling. This method will hopefully allow the OURS project to collate an estimate of our Yukon bear populations and improve the scope of our bear-related knowledge. If you want to learn more about the project, check out the OURS Facebook and iNaturalist page and consider, come this spring, being part of the bear bowel movement collection crew!
Joelle is a former archaeologist, former wildlife interpreter, and a full-time random fact enthusiast. She received her master’s degree in anthropology from McMaster University. One of the four people who read her thesis gave it the glowing review “It’s a paper that would appeal to very specific group of people,” which is probably why only four people have read it. Her favourite land mammal is a muskox, her favourite aquatic mammal is a narwhal. She thinks it’s important that you know that.