Raccoons Get A New Call

In Virginia, University of Richmond neuroscientist Kelly Lambert studies depression, anxiety, resilience and stress.

So she was intrigued when she heard about a raccoon that quickly scaled a 25-story office tower in St. Paul, Minnesota, looking as adept as a pro rock climber climbing El Capitan. dr Lambert called animal control specialists as soon as she learned they had caught the animal.

Quite the tail

“Send me his poop because that’s a hardy raccoon,” she recalls. “Of course they thought I was crazy.” (Scientists can measure stress-related hormones in feces.)

Decades ago, science largely abolished raccoons because they behaved like, well, wild goblins. Now they are experiencing a renaissance.

Researchers are studying raccoons to gain insights into intelligence and emotions, aided by technology like wireless sensors and night vision cameras that allow the cunning masked bandits to be observed on their own territory. Advanced molecular tools allow neuroscientists to study brains, including raccoons, down to the cellular level.

The similarities between human and raccoon brains make the animals good models for learning how experience changes the brain, says Dr. Lambert.

Hannah Griebling, Ph.D. University of British Columbia student sets traps between 4am and 5am and catches two raccoons

“Exploration, curiosity, ideas, optimism, maybe anticipation,” she adds. “I think the raccoons could teach us something about that.”

Raccoons are unscrupulous and have frustrated researchers for more than a century.

“The raccoon has a high reputation for cunning and dexterity,” says a 1907 scholarly paper of a study in which they were used or attempted. Raccoons escaped from their cages by tearing down the wire mesh and they jumped out of windows. Some were hiding in ventilation shafts and it took a lot of effort to get them out.

As uncooperative as raccoons were in the laboratory, their nocturnal habits made them more difficult to study in the wild.

Ultimately, the researchers settled on more manageable experimental animals, such as rodents and birds, to study how different species learn.

With new study tools, raccoons are playing a starring role in research, including a 2021 study in which Dr. Lambert and her teammates challenged the animals to open a clear box containing a gourmet treat: a plum dipped in sardine juice.

A sedated raccoon named Ali is tested and cared for by the team.

The scientists used night vision cameras to monitor how raccoons negotiated a trio of complex obstacles, such as: B. using a latch to open a small door to get a treat, and then had to toggle to slide a window, for example – when the latch option was locked.

Animals that could successfully open doors in three different ways were, according to Dr. Lambert super performers; those who opened two doors were mediocre, and so on. However, all three groups had comparable amounts of neurons in a brain region that processes sensory information from their paws. This indicated that mere skill was not the whole truth.

The researchers found that the supersolvers had more support cells called glia in the hippocampus, a brain region crucial for learning and memory. Glial cells protect against inflammation and help communicate between neurons — the brain cells that store memories and underpin movement, hearing, and other complex behaviors. Having more glial cells is associated with more adaptive cognition, the researchers said.

Daniela Hernandez from the WSJ explains how the raccoon brain fares compared to the human brain and why it is becoming increasingly important in laboratory experiments. Illustration: David Fang

A small study found that Albert Einstein’s brain had more glial cells supporting neurons than the brains of men of average intelligence. “Maybe we had little Einstein raccoons,” says Dr. Lambert.

Other research has found that the density of neurons in raccoon brains relative to size is similar to that of humans. “There are neural reasons why we can’t figure out garbage cans that they can’t get into,” she says.

Lauren Stanton, a cognitive ecologist at the University of California, Berkeley, uses sardines and peanut butter to attract raccoons. She then tags them with electronic tracking beacons and releases them into the wild so she can study how smart they are.

Raccoons seem to remember the trick, making them difficult to recapture using the same strategy. fool you twice? Unlikely, man.

Cognitive ecologist Sarah Benson-Amram and graduate student Liz Babbitt release raccoons near where they were trapped earlier that day.

For a study published in September in the Journal of Experimental Biology, Drs. Stanton and her team test mental flexibility, the ability to change strategies when an approach no longer works. They tagged raccoons with the beacons and watched them mess around with a two-button box. Raccoon contestants named Allspice, Caper, Chia, and Tarragon had to learn who gave out a treat, a dog food. The win button was not the same every time.

It turns out that carefree raccoons who spent time learning the rules of the game were rewarded, while aggressive raccoons gave up and ran away.

Perhaps “more docile individuals are actually the masterminds,” says Dr. Stanton.

Night vision cameras show that raccoons have a rich social repertoire. They greet each other sometimes. Some use their butts to push other raccoons out of the way. Sarah Benson-Amram, a cognitive ecologist at the University of British Columbia and author of the study, says that she and her team are mapping raccoons’ social networks to assess whether their box-opening strategies are permeating social groups. However, scientists assume that most people appreciate raccoons from afar.

“Everything looks very nice,” says Dr. Stanton. But “they can be quite a handful.”

A raccoon in Vancouver, British Columbia, is released hours after it was caught for testing.

write to Daniela Hernandez at [email protected]