raccoon smart box
Why are raccoons so good at living in cities? One theory is that this is because they have flexible thinking. To test this idea, cognitive ecologist Lauren Stanton of the University of California, Berkeley, employed a classic laboratory experiment called the reversal learning task. In this test, animals are rewarded by learning to consistently choose one of two options, but then the correct answer is reversed and the other option results in a reward. People with flexible thinking are better able to deal with reversals. “They should be able to switch their choices more and become faster over time,” Stanton said.
To test the learning abilities of wild urban raccoons in Laramie, Wyoming, Stanton and her team built a series of “smart boxes” to be deployed on the outskirts of the city. Each box was fitted with an antenna to identify previously captured and microchipped raccoons. Inside the box, the raccoon found two large buttons procured from an arcade supplier and pressed them, one of which gave him a reward. Hidden in a separate compartment, an inexpensive Raspberry Pi computer board powered by a motorcycle battery recorded which buttons the raccoon pressed and toggled the reward button as soon as it answered nine out of 10 questions correctly. . A motor rotated a perforated disc under the funnel, dispensing the reward dog kibble.
Many raccoons and some skunks were surprisingly enthusiastic participants, which made it difficult to obtain clean data. “We put multiple raccoons into the device at the same time. Three or four raccoons competed to get into the device at the same time,” Stanton said. I also had to use super glue to keep the buttons on because a few particularly enthusiastic raccoons ripped them off. (She had placed some grains inside the transparent buttons to encourage the animals to press the buttons.)
Surprisingly, the smart box revealed that shy and docile raccoons were the best learners.
jumping spider eye tracker
What intrigues behavioral ecologist Elizabeth Jacob about jumping spiders is their attitude. “They always have such a curious look on their faces,” she says. Unlike other arachnids, which spend most of their time motionless in their webs, jumping spiders roam outside, hunting prey and courting mates. Jacob is interested in what goes on inside their sesame-sized brains. What’s important to this little spider?
barrett klein
For clues, Jacob looks at their eyes, specifically the two primary eyes with highly sensitive color vision located at the center of the boomerang-shaped retina. She uses a tool developed more than half a century ago from an ophthalmoscope that was specially modified to study the eyes of jumping spiders. Generations of scientists, including Jacob and his students at Massachusetts Amherst, built on this design and turned it into a mini-cinema that tracks the retinal tube as it moves and twists behind the spider’s main eye. It has slowly transformed.
A spider is tethered in front of a tracker, and a video of the silhouette of, say, a cricket is projected through the tracker’s lens into the spider’s eye. At the same time, the infrared rays are reflected by the spider’s retina, passed back through the lens, and are recorded by the camera. Recordings of those reflections are overlaid on video to show exactly what the spider was seeing. Jacob discovered that the only thing more interesting to a jumping spider than a possible cricket dinner was a growing black spot. Could it be an approaching predator? The spider’s low-resolution second eye glimpses a looming spot in the corner of the video screen, prompting it to move away from the cricket to get a better look at its master’s eye.
