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The Secret To Tracking And Mapping Bears
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A bear-proof garbage can is a pretty simple device. It’s sturdy, it’s metal and its latch is protected by a cover that makes it difficult for a paw to access it. (On my recent trip to Alaska, I found these trash cans to also be somewhat Jody-proof. I eventually got the hang of it.) These bins don’t just appear out of nowhere — the arrival of a bear-proof trash can in a town or backyard may be the end result of a pretty complicated process that involved some serious data.

On this week’s What’s The Point, Rae Wynn-Grant, a conservation researcher at the American Museum of Natural History, discusses her work with black bears in the American West. Her goal is to understand their population changes, movements and habitats — and how those come into conflict with human behavior. To do so, she uses a combination of GPS information to track movement and geographic data (GIS) to map habitats, landscape, roads and more. Her work leads to recommendations about which areas to preserve, which land to develop and — yes — where to install bear-proof trash cans.

A partial transcript of the conversation is below, and here a few links to articles on Wynn-Grant’s work, including her efforts to increase diversity in conservation and science:

Where the bears aren’t

Jody Avirgan: Has there been a moment where you’ve been surprised by where bears are located?

Rae Wynn-Grant: I think more often I’m not finding animals in places I would expect them to be. That’s always interesting. If I have a habitat that has lots of what we call hard and soft “mast,” meaning resources that trees produce that animals can eat, I would expect to find a bear there — a place with lots of berries and fruit and deer having calves and birds laying eggs, all these natural resources. … But it’s possible that I won’t be able to trap a bear there. And that’s really interesting.

What my modeling has told me is that often those areas have a certain level of human influence that actually deters black bears. So in the area where I work (in Nevada), there’s a lot of human recreation in the back-country. A lot of people use these mountains and forested areas for hiking and camping and fishing and hunting. And if you have a single hiker who’s walking around the forest, you wouldn’t think that would be a huge problem for a bear. You wouldn’t think that would keep them kilometers and kilometers away. But I’m finding that it really does repel them.

Avirgan: And I’m assuming these are people who probably think of themselves as nature lovers and conservationists, too.

Wynn-Grant: Exactly. So we’re finding from this research that humans have a much bigger impact to animal communities, and in particular large carnivore communities, than we’d previously thought.

How development attracts and repels bear populations

Wynn-Grant: In a lot of ways, if there’s a big road or a ski resort, bears are avoiding it. But I’m also finding that some places, which I call recreation sites and which are essentially campsites — bears are actually more attracted to those areas.

Avirgan: Because there’s food there?

Wynn-Grant: Because there’s easy food there.

Avirgan: You also see this in the suburbs of New Jersey. Is that the same [problem], people are leaving garbage cans open?

Wynn-Grant: It is — it’s exactly the same. I’ll back up and say that bear populations are growing throughout the United States. It’s a conservation success story. So there used to just not be that many bears in New Jersey. But now the bear populations are doing very well, and we’re experiencing lots of human-bear conflict. Bears used to have the entire state of New Jersey to themselves, it was all forest, and now there are suburbs that were built in bear habitat.

The bears are essentially confused. On the one hand, there are all these resources — trash — for them to eat, and on the other hand, there’s all these people, and the bears have to make a decision: What’s more important: access the trash or avoid these people? And because bears experience hibernation for much of the year, they actually are more attracted to the resources that will allow them to be fatter during hibernation than avoiding what might be a big danger.

Avirgan: Meaning that from the bear’s perspective, they are just trying to be as efficient as possible in their window to eat as much as possible. And if that involves opening a trash can, they’ll do it.

Wynn-Grant: Exactly! You just hit on what we call Optimal Foraging Theory.

Avirgan: Yeah, I knew that, but I didn’t want to drop that term.

Wynn-Grant: You didn’t want to brag. But, yes, that’s what it’s called. For all wildlife species, their inherent goal is to consume as many calories as possible by expending the least amount of energy possible. And people do that too. It’s way easier for us to go to the grocery store than it is to grow and harvest our own food. Bears are doing that.

Avirgan: I can’t wait for the back-to-the-land bear movement.

Wynn-Grant: Like a farm-to-table bear movement. It’s coming.


If you’re a fan of What’s The Point, subscribe on Apple Podcasts, and please leave a rating/review — that helps spread the word to other listeners. And be sure to check out our sports show Hot Takedown as well. Have something to say about this episode, or have an idea for a future show? Get in touch by email, on Twitter, or in the comments.

What’s The Point’s music was composed by Hrishikesh Hirway, host of the “Song Exploder” podcast. Download our theme music.

Jody Avirgan hosts and produces podcasts for FiveThirtyEight.

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