UW research explores the cognitive abilities of urban wildlife
In Laramie’s urban raccoon population, who fares better? The docile or the aggressive? Animal cognition researchers at the University of Wyoming dig into that question in a new paper.
Anyone who has taken a stroll through the tree neighborhood after sunset will know Laramie has a thriving raccoon population.
The raccoons are such a visible feature of Laramie that the University of Wyoming hosts its own research group dedicated to the study of the famously clever creatures.
But in an urban environment like Laramie, which raccoons are likeliest to succeed — the more docile, or the more aggressive?
That’s what some UW researchers sought to answer in their recent paper, “Environmental, individual and social traits of free ranging raccoons influence performance in cognitive testing” published in the Journal of Experimental Biology last month.
Lead researcher Lauren Stanton and her team tested the cognitive abilities of wild raccoons in Laramie.
“The study was inspired by wanting to understand the role of cognitive abilities, like problem-solving, of wildlife living in urban environments,” Stanton said. “Our research group is really interested in how animals use learning and problem-solving abilities and behavioral flexibility to live alongside humans.”
Stanton said that the team decided to conduct research on raccoons because the species is highly adaptive and can be found in most urban areas across North America.
The team wanted to step outside of the lab, by having the testing take place in a field setting. That ensured that a raccoon’s cognitive abilities were tested in the raccoon’s natural environment, rather than in captivity.
The team trapped 204 raccoons between August 2015 and September 2019. All raccoons were returned to trapping sites once biological samples were taken and a passive integrated transponder, or PIT, tag was administered for tracking. PIT tags are similar to microchips used to track dogs or cats.
“During the whole trapping process, we would trap raccoons and bring them from the field to Red Buttes lab, where we would process them. That whole time while trapping and bringing the raccoons to the lab we were recording their behavior towards us.” Stanton said. “We were interested in how much they were moving in the trap, whether they were sticking their paws outside of the trap, and most importantly when they would vocalize at us — so anytime they would admit some kind of aggressive vocalization, like a growl, snarl or bark, we would record that and use it as a measure of their temperament.”
The raccoons were rated with different scores for their level of docility or aggressiveness, depending on their responses to their human captors.
Back in their home habitat, the raccoons encountered “Skinner boxes” — devices left by the researchers which could distribute either the reward of food or the punishment of an unpleasant sound.
The Skinner boxes were made from plywood and contained a long-range RFID (Radio Frequency Identification) antenna. The boxes would activate when a PIT tag was detected and it would emit food for the raccoon.
The boxes also had two buttons that, when pressed, would either supply the raccoon with more food or make an unpleasant noise for a short time.
The team found that the more docile animals possessed more ability to interact with the Skinner boxes.
The team found juvenile raccoons were more likely to interact with the boxes and more likely to figure out how to operate the boxes than older raccoons.
“Part of the study we were really interested in was linking individual traits of raccoons to their cognitive abilities and their success at different tasks. We were thinking of things like age, sex and temperament.”
As Wyoming-based bear biologists have highlighted, close proximity to humans can shape animal behavior and the temperamental make-up of a wildlife population.
The same is true for raccoons.
“For a long time we’ve thought that urban environments were making animals bolder — they are more likely to approach people, they’re less afraid of people, they’re getting habituated to people and human environments,” Stanton said. “That certainly could be the case in some species and some populations.”
But a simultaneous change might be going on with raccoons, Stanton said, when raccoons considered a nuisance are removed from the population.
“Whether it's lethally or just moved, if an animal gets too high of a level of boldness it could be that they are considered problematic individuals,” Stanton said. “Animals that are potentially more docile towards humans and are more habituated to stimuli in urban environments are maybe more favorable for some species in urban areas.”
Reactive or docile animals could be more favorable in urban settings than those that are proactive or aggressive and bolder.
“We typically tend to think of bold or aggressive animals as more problematic in conflict situations but that might not be the full story,” Stanton said. “It could be that the more docile animals are better learners and problem-solvers, so they are the real masterminds and are able to capitalize on human resources. Which can unfortunately also lead to conflict. So an important takeaway is if we are taking away certain individuals from the population, what does the remainder look like?”
UW raccoon research frequently makes national and international news for its contributions to the field of animal cognition research.