How our actions are making raccoons smarter | Webby Award Winner | Nat Geo Explores
[Narrator] These little creatures can be complicated. They're cute, but mischievous. It's my pizza. They may have earned a bad rap from their antics, but their problem-solving skills inspire scientific studies. Interactions with them are unpredictable, and as our cities spread into their homes, that's only increasing. So, let's take a closer look at raccoons.
I think I have one of the best jobs in the world. I am endlessly fascinated by animals, in particular, animal cognition and animal behavior.
[Narrator] This is Dr. Sarah Benson-Amram, and she works with some pretty great office mates.
I find it a really fun challenge to try to put myself into the minds of these animals and come up with a task that I think is going to be fair and actually get at the cognitive ability that I'm trying to assess. Every time we test the raccoons, it just ends up leading to 20 more questions. You could study them for a lifetime and never get bored.
[Narrator] Smart, adaptable and carrying a famous resemblance around the eyes, Native American folklore tells of a muddy brawl with a coyote that caused the face mask, and their know-it-all antics, from being the reincarnation of a disobedient human. Whether past or present, they leave an impression.
Raccoons definitely have a reputation for being mischievous, and they're very good at doing things that we can find pretty frustrating, like breaking into trash cans or getting into your house.
[Narrator] But to be fair, (chainsaw runs) we're kind of breaking into theirs.
We're taking over more natural land and more wildlife are getting pushed into human dominated landscapes.
[Narrator] And we're talking a lot of landscapes, like 24 million acres of natural space lost to urban expansion. That's the size of nine Grand Canyons.
[Dr. Sarah Benson-Amram] You have a lot of wildlife that is declining and even disappearing from some areas, but then you also have these other wildlife species that are able to successfully live in cities and sometimes even use human-provided resources.
[Narrator] Which brings us back to our crafty neighbors.
Raccoons are really adept at changing their behavior, but they're not avoiding people as much as they're taking advantage of a lot of the resources.
[Narrator] Despite how hard we try to keep them away.
We put fences, we put bungee cords on our trash cans. So we're basically presenting urban wildlife with increasingly difficult challenges, and they're solving those challenges.
[Narrator] Which raises the question, just how smart are these animals?
We've given them different cognitive tasks to specifically assess this ability of theirs to change their behavior rapidly.
[Narrator] One test studies cognitive flexibility with a three-part puzzle. Another looks at reversal learning by pressing buttons. But it's a fable from a couple thousand years ago that inspires the third.
The Aesop's fable paradigm is taken from the Aesop's fable, "The Crow & the Pitcher". There's a thirsty crow, and it finds a pitcher of water. There's only a little bit of water in that pitcher, and the crow can't reach it, so this Crow drops stones into the pitcher, which raises the water level, now that the crow can get a drink.
[Narrator] And in real life, birds like rooks and crows can actually solve this problem, as well as another animal you might recognize.
We found some really interesting differences between what we see with raccoons and what they see in other studies. Unlike the Corvids, they don't just take one stone, drop it in, get the reward, and finish. They actually take all the stones, dump them all in, and just are playing with this thing constantly. So they get the reward, but then they just keep playing with it or they take the stones and they go hide them in their bedding so that they can play with them later. Once the raccoons learn this, you can test them to see really how much they understand about the problem. For example, you can give them a floating ball versus a sinking ball. If they understand they should choose the sinking ball because the floating ball won't actually help them to get their reward. They actually didn't show a preference for the sinking ball. What they've figured out is that they could actually make the floating ball work. They learned to push it up and down in the water to bounce it, and that would spray marshmallow bits up the side of the tube so they could get the reward. So we're seeing that they're really creative problem solvers.
[Narrator] So for those skilled problem solvers, what can we learn from their brains?
Raccoons, who can solve a problem in multiple ways, have more cells in their hippocampus, and the hippocampus is thought to be this really important brain region for cognition, specifically memory and learning. Interestingly it's actually that they have more non-neuronal cells, so things like glia.
[Narrator] Which is helpful, considering a higher ratio of glia to neurons could increase neuroplasticity, which is your ability to flexibly switch your behavior.
[Dr. Sarah Benson-Amram] Albert Einstein, notably, had a really high glia to neuron ratio and humans actually have a higher glia to neuron ratio than other primates.
[Narrator] So we're learning that raccoon brain power plays a role in their cognitive flexibility, but there's another physical feature that contributes to their craftiness.
[Dr. Sarah Benson-Amram] Raccoons are very famous for their dextrous forepaws. So they have these five long fingers like primates.
[Narrator] Just without opposable thumbs.
Hey.
[Dr. Sarah Benson-Amram] Instead they can use sort of both forepaws together to lift and then manipulate objects.
[Narrator] And while this manipulation skill is handy. (Audience groans) All right. All right. It's not their only feature.
Their sense of touch is incredibly sensitive. Evolutionarily raccoons were trying to find food in really murky water or in the dirt underneath the water. And so they're digging around, but they're not able to see what they're doing, and so they're really heavily relying on this tactile ability.
[Narrator] Which explains another endearing trait they've held onto.
[Audience Member] Come on.
People think, "Oh, when raccoons put something in water, they're washing it," but actually when they put something in water, their tactile sense is heightened to feel things even more finely. As urban environments start expanding that can have a lot of really dramatic consequences for wildlife. Designing mitigation strategies for human-wildlife conflict will be really critical.
[Narrator] For some cities, ecological restoration has already shown promising results. By boosting biodiversity, reducing city pollution, and connecting people with nature.
There is this effect that when people connect to nature in their backyards then they connect to nature even more globally. They're more likely to be involved in conservation efforts around the world, and so that's something that we're really excited about to help people to get involved in community science projects and to really get people excited about what's happening in their city, in their backyard, with wildlife.