Several of our projects are based in the Kluane Lake region of the southwestern Yukon. Researchers there have recently observed the first case of “river piracy” caused by anthropogenic climate change. The article linked above explores river piracy and other changes in Kluane that may be attributed to climate change. University of Alberta ecologists Stan Boutin and David Hik are featured in the article.
The winter! the brightness that blinds you,
The white land locked tight as a drum,
The cold fear that follows and finds you,
The silence that bludgeons you dumb.
The snows that are older than history,
The woods where the weird shadows slant;
The stillness, the moonlight, the mystery,
I’ve bade ’em good-by—but I can’t.
– Robert Service, “The Spell of the Yukon”
I spent January of this year in the boreal forests of Kluane, Yukon. My goal was to collect pictures, fur samples, and tracks of Canada lynx in order to estimate density of lynx in the Kluane area. My Master’s project compares methods of density estimation to improve lynx research and management. Every few months I head to my field site in Kluane. I have experienced every season of the year in the Yukon, from the midnight sun in summer to the deep dark and cold of winter. No time of the year is quite like January.
Most of my time in Kluane, regardless of season, is spent hiking. This becomes particularly challenging in winter. This year, temperatures dipped to -35 Celsius and snow was thigh-deep in many places. Bailey (my field assistant/ hiking buddy) and I looked to lynx for advice on how to traverse long distances in deep snow. Lynx have disproportionately large feet, making them look funny in summer but helping them keep up with their prey in winter. Their feet function as snowshoes to distribute their weight and help them float on top of the snow. So, Bailey and I got some snowshoes. Not just any snowshoes; modern, lightweight snowshoes were ineffective in snow that deep. In order to make it to all our remote cameras and fur snag sites, we had to borrow extra-large, old-school snowshoes from a local outdoorsman. After a steep learning curve where we learned to walk without tripping (sometimes), the snowshoes became indispensable to our everyday hikes.
Cold temperatures were less easily dealt with. Lynx grow big fur coats every winter, with a beard around their neck for a scarf and thick fur between their toes for boots. All Bailey and I could do was outfit ourselves in the human-made substitutes. No matter how much we layered up, we still lost heat throughout the day and had to manage it as best we could. When temperatures were low, lunch breaks to eat our (frozen) sandwiches were limited at five or ten minutes, or until the cold caught up to us. Taking off our mittens even briefly to check cameras or to make a note was painful. Camera screens wouldn’t work, handheld GPSs would turn off mid-hike, and even pen ink would freeze. The Yukon cold did not make our fieldwork easy.
Despite the deep snow and the deep cold, Bailey and I headed outside each day to take advantage of every hour of daylight available. A key lesson that I learned this field season is that tough conditions are not as tough when you have a friend by your side to experience it all with you. Long sunrises and sunsets, Northern Lights to light up the night, and expansive white landscapes can help counter the extreme conditions with extreme beauty. And the real reward for the tough times was a lot of data. We collected about 250 pictures of lynx and 100 fur samples for analysis in that month. Every successful camera or fur snag and every lynx track in the snow is another piece of the puzzle to understanding lynx populations and improving our management of an ecologically, economically, and culturally important wildlife species.
I will return to Kluane for the last time in June. I look forward to experiencing yet another side of the North. By June, everything will have turned from bright white to bright green. The winter challenges of cold and snow will be exchanged for mosquitoes and mud. Long days will keep me outside for hours on end, and I look forward to returning to camp every day tired and happy. But I will certainly miss the Kluane winter and everything it offers. Again in the words of Robert Service:
There are hardships that nobody reckons;
There are valleys unpeopled and still;
There’s a land – oh it beckons and beckons,
And I want to go back- and I will.
– “The Spell of the Yukon”
New article in UpHere on featuring Michael Peers
As most regions of the earth transition to altered climatic conditions, new methods are needed to identify the most likely refuges for biodiversity and to prioritize conservation actions. A variety of metrics and approaches have been proposed. Some are based on predicting future climates and rates of change (“climate velocity”). Others use only information on the current environment, finding areas where there are steep elevation gradients or topographic variation (“environmental diversity”) that help species to find climate refuges nearby. Faced with high stakes and a wide array of conservation targets, planners and land managers need new tools to deal with these new challenges.
In a new open-access paper published in Global Change Biology, led by Carlos Carroll and co-authored by U of A researchers Diana Stralberg, Scott Nielsen, and Andreas Hamann as part of the AdaptWestinitiative, we set out to compare a variety of velocity and diversity metrics for conservation planning under climate change across North America. Specifically, we evaluated similarities and differences among different methods across different spatial scales and elevation ranges. Not surprisingly, we found substantial variation among metrics. But somewhat remarkably given uncertainty around future climate change projections, there was more variation among environmental diversity metrics based on current environmental conditions than among climate velocity metrics based on alternative future climates. We also found that while all diversity and velocity metrics generally increase with elevation, so do the contrasts among them, due to interactions between climate and terrain (see figure below).
So what is a planner to do, given all these differences? We suggest that metrics be combined, with areas of greater variation down-weighted (all spatial data are being made available through AdaptWest). Alternatively, finer-scale diversity metrics can be substituted where available, and supplemented with data on key target species as needed. Climate velocity metrics are useful for identifying broad-scale “macro-refugia,” where more species may find a long-term refuge from climate change. Areas of high environmental diversity should correspond with greater potential for local “micro-refugia” that can serve as temporary havens for species under a climate in flux. Where they coincide, short- and long-term conservation potential can be achieved most efficiently. We found that neither type was well-represented by the current protected area system, suggesting that much conservation work is still needed in order to prepare and adapt where possible to climate change.
Citation: Carroll, C., Roberts, D.R., Michalak, J.L., Lawler, J.J., Nielsen, S.E., Stralberg, D., Hamann, A., McRae, B.H., Wang, T. 2017. Scale-dependent complementarity of climatic velocity and environmental diversity for identifying priority areas for conservation under climate change. Global Change Biology (early view).
Field course in Kananaskis: A unique opportunity to gain hands-on field experience, including working with wild animals!
See the attached brochure for more information
contact Stan Boutin (email@example.com)
attend an info session March 20 at noon-1pm or 21 at March 23 at 5-6pm. Both session will be held in CCIS 1-243
Enrolment is limited so register early
Photo from Kluane trail cams courtesy of Darcy Doran-Myers
Hitching a ride with a carnivore
Plants can’t move. That may seem like an obvious statement, but it has a lot of consequences for how plants live their lives and the kinds of adaptations that they have. Not being able to move is particularly problematic when they have offspring. For example, if a plant’s offspring grew next to the parent plant, the parent and offspring would probably end up competing with each other for space, water, and nutrients for the rest of their lives. So parent plants have to get creative in transporting their offspring elsewhere, even though the parents themselves cannot move. This movement away from the parent plant is called dispersal. Some plants have solved this problem by manipulating animals to transport their seeds. For example, their seeds could be contained within a fleshy, edible fruit that would then be eaten by a foraging animal. After the edible fruit was digested, the seeds could be deposited some distance away, thus solving the parent plant’s problem. Having seeds transported in this way comes with the added benefit that animal poop can be highly nutritious, which is great for a seedling just starting to grow. However, it’s pretty common that seeds don’t just germinate wherever they’re deposited: seeds are often transported by multiple animals or other means such as wind or water. For example, a cherry eaten by a bird could have its seed first deposited by the bird and then transported by ants where it then grows into a cherry tree.
We were interested in seed dispersal because this process can get quite bizarre. Many animals that eat seeds or fruit fall prey to predators. If the prey had recently eaten, they could still have seeds or fruit in their gut when they were killed by the predator. This means that the seeds that started out being eaten and then dispersed by one animal, ended up in the gut of a predator instead. In our cherry tree scenario, this could happen if the bird ate the cherry only to be consumed by a fox afterward. The cherry seed could then hitch a ride with the fox instead of the bird. The process of a seed being transported in the gut of multiple animals, such as first by a prey animal that was then eaten by a predator, is called diploendozoochory.
Our paper was recently published in Ecosphere and is Open Access:
We wanted to know how widespread this phenomenon was and how important it was for plant populations. After reviewing scientific literature, we found that this kind of predator-assisted seed dispersal was first described by Charles Darwin in 1859. Since then, there have been other sporadic observations and we found that there is potential for this phenomenon to occur in many habitats and species. These studies showed that seeds consumed by prey that were eaten by predators may be moved greater distances than seeds deposited by the prey alone. Predators and prey may travel through different kinds of habitats, which means that seeds can end up in different places depending on who deposits them. Some seeds have particularly thick shells, which must be cracked open for the seedlings to grow. These plants can benefit from the wear and tear of passing through the guts of two animals, making them better able to germinate than if they had passed through the gut of the prey alone. It’s even possible that some plants have evolved specifically to take advantage of these predator-specific behaviours, in other words their seeds have evolved counting on the prey being eaten by a predator. However, these different factors are like pieces in a puzzle: to fully understand the big picture of how they affect plant populations, we need to know how all of these pieces fit together. So far, studies have only looked at small parts of the puzzle, and no study has put all of the pieces together to see the overall importance of this phenomenon for plant populations or its role in seed evolution.
Because predators may transport seeds somewhere different than prey, diploendozoochory has broader impacts than just affecting plant populations. For example, predators are often larger than their prey and can thus cover larger distances. As humans continue to fragment and alter wilderness, such as by cutting down forests or building roads, predators may be the only animals large enough to navigate across these areas and enable plants to recolonize them. Climate change will alter where some plants can find suitable places to grow, and seed-carrying predators could have a role in helping plants cover a larger area and hence move with the changing climate. On the other hand, plants that have been introduced to new countries and continents by humans, called introduced or invasive species, may invade new areas faster thanks to predators giving them a hand. Our work has highlighted how interesting and important this phenomenon is, and we hope that it will help and encourage others to fill some of these gaps in our understanding.
More info can be found here: