Guest post by Cassandre Venumière Lefebvre, 2025-2026 Sustainability Leadership Fellow and Ph.D. Candidate in the Department of Fish, Wildlife, and Conservation Biology

I am driving along the highway through Wyoming and can only send quick glances eastward. Out of the rust-colored fields, a furtive spot of white suddenly distinguishes itself from the grass, then another. Through repeated efforts, I can now identify a dozen pronghorn antelopes in the distance. For the third time, I am finishing the year by driving from Fort Collins to Bozeman to visit some dear friends, have some alpine adventures, play board games, and drink black currant cider before migrating back south to start a new calendar year. As I see the landscape unrolling before my eyes, I wonder what drives these antelopes on their own migration path. Just west of this road is the Greater Yellowstone Ecosystem – a mosaic of federal, state, tribal, and private lands that protect wildlife habitat and allows for large animal movement. It hosts a number of carnivores, including wolverines, lynx, and grizzly bears (as depicted in the banner picture). It is also an important movement corridor for ungulates (i.e., hoofed animals, which in Yellowstone include bighorn sheep, elk, and bison, as seen on the following picture). Finding many large mammals moving through this landscape is expected. Yet, I am still taken by the wonder of large scale, directional, animal movement. Where are they going, and how do they decide when and where to go? 

How do animals decide where to go?

I have always been fascinated by this question. As a child, I learned bats rely on echolocation to navigate the three-dimensional volume of the air space and tiny monarch butterflies migrate across an entire continent to spend the winter in a warmer habitat (pictured below). These examples struck me, perhaps because of the scale of those movements or perhaps because they involved animals relying on different senses than I do to perceive the world. How can we relate to those critters? This mystery sparked my interest, and contributed to my curiosity towards other life forms and, particularly, behaviors.

Today, as a conservation ecologist, understanding how animals make decisions and move through a landscape has become a question that I am interested in answering to inform policy and management. Although we can never truly know what it is like for a bat to be a bat, we can collect data on animals as they move, including their position at a specific time and elements of the environment at that time. With this information, we can deduct which environmental cues they rely on to make their decisions. Those environmental cues that influence animal decisions might be temperature, precipitation, luminosity, terrain, vegetation abundance, or other animals. They might try to follow prey, avoid predators, or either avoid or seek the proximity of conspecifics (i.e., other individuals of the same species), for example other males that might compete for territory, or other members of a herd that might offer protection. As managers, understanding this decision-making can help us protect habitat that animals seek for food, protection, travel, or reproduction.

Negotiating with wildlife to coexist

If we understand it, we can also influence this decision-making for conservation, something I recently became very interested in. Can we change the cues of the environment to tell animals to behave differently, to go one way rather than another, in a way that benefits both their conservation and our human activities? Doing so would unlock a possibility to negotiate with wildlife, to use diplomacy to coexist with nature.

I am interested in testing this kind of diplomatic strategy between mountain communities in Colorado and black bears. American black bears are omnivorous, they can eat a large variety of foods, including acorns, berries, insects, or, when they can catch them fish and deer fawns. This dietary flexibility lets them adjust to many new environments, and to changing conditions, making them a very resilient species. They are ingenious, and when resources are scarce, they can travel large distances to find more, or learn to rely on new sources of food, sometimes putting themselves in risky situations to do so, if they must. One only needs to scroll down social media in September or type “bear / birdseed / acrobatics” in any internet browser to discover how resourceful black bears are with their paws, mouth, nearby props, or gravity to gain access to food. In southwestern U.S., in years when drought or late spring freezes affect most of the acorns and berries that bears usually rely on for food, bears turn from natural food to human food like garbage, bird feeders, composts, barbecue grills, or any other source of food that we leave outside our doors. However, in our communities, we expect to be able to walk our children to school or read in our backyards without worrying about a bear in the nearby tree. In other words, our need for safety and bears’ adaptive feeding behaviors conflict. 

In Durango, a mountain city in southwest Colorado, the community recognized that they were sending contradictory messages to bears: inviting them in with garbage and birdseed but chasing them away with guns, pyrotechnics, and other deterrents. In 2013, the city, the state wildlife agency, and community members came together and tried to remove the garbage invitation by using bear-resistant trash containers in two neighborhoods. Colleagues and myself were interested in evaluating whether this message was perceived by its recipient: did bears notice the change in the distribution and availability of resources in this urban landscape, and change their behavior accordingly by avoiding these neighborhoods? 

They did. Garbage was less often found strewn around in the two neighborhoods, and bears spent less time in those places. Further, they spent less and less time each year in those neighborhoods, meaning that they progressively learned that the lack of reward was no longer worth the risk of crossing highways and braving gunshots.

There is often more negative than positive news in environmental conservation, so finding out that a solution shows promise to limit human-caused bear mortality is worth celebrating. On a personal note, I also loved the mental perspective shift that this project required of me. To properly model bear movement in order to find out if the trash cans worked, I had to account for all the environmental signals that a bear uses as cues. To think like a bear, I walked along the bike path that follows the Animas river in Durango and noticed how much human activity occurs, and wondered if that would deter a bear from using the river as a pathway into the city. Families whitewater rafting and friend groups playing music in local parks took a different color for me. Later, I spent many hours with a colleague scrutinizing Google Earth views of the city to figure out why this specific hill between two residential areas had so much bear passage – was it that the slope prevented housing development, creating a safer passage point for bears than the nearby residential streets?

Invitation to shape shift

So I invite you, Reader, to perform a similar mental exercise the next time you find yourself at the “urban-wildlife interface”, in a place where people walk, talk, relax, run, and that other species also may use. I invite you to shift your view of what surrounds you and try to guess what sort of message each element of the landscape around you may send to a non-human resident of this space.

Banner picture: Pronghorn antelopes in a grass field in Idaho, photo by Brett Sayles.