What do jumping spiders find sexy? How DIY tech is offering insights into the animal mind.

The raccoon good field

Why are raccoons so good at metropolis dwelling? One idea is that it’s as a result of they’re versatile thinkers. To check this concept, UC Berkeley cognitive ecologist Lauren Stanton tailored a traditional laboratory experiment, known as the reversal studying process. For this take a look at, an animal is rewarded for studying to persistently select one among two choices, however then the proper reply is reversed in order that the opposite possibility brings the reward. Versatile thinkers are higher at reacting to the reversals. “They’re going to be extra in a position to swap their decisions, and over time, they need to be sooner,” Stanton says.

To check the training expertise of untamed city raccoons in Laramie, Wyoming, Stanton and her crew constructed a set of “good containers” to deploy on the outskirts of the town, every with an antenna to determine raccoons that had beforehand been captured and microchipped. Contained in the field, raccoons discovered two giant buttons—sourced from an arcade provider—that they might push, one among which delivered a reward. Hidden in a separate compartment, a reasonable Raspberry Pi laptop board, powered by a bike battery, recorded which buttons the raccoons pushed and switched the reward button as quickly as they made 9 out of 10 appropriate decisions. A motor turned a disc with holes in it under a funnel to dispense the reward of canine kibble. 

Many raccoons—and a few skunks—have been surprisingly desperate to take part, which made getting clear knowledge a problem. “We had a number of raccoons simply shove contained in the system on the similar time, like, three, 4 animals all making an attempt to compete to get into it,” Stanton says. She additionally needed to make use of stronger adhesive to carry the buttons on after a couple of significantly enthusiastic raccoons ripped them off. (She had positioned some kibble contained in the clear buttons to encourage the animals to push them.) 

Surprisingly, the good containers revealed that the shyer, extra docile raccoons have been the very best learners. 

The leaping spider eye tracker

The factor about leaping spiders that intrigues behavioral ecologist Elizabeth Jakob is their demeanor. “They give the impression of being so curious on a regular basis,” she says. Not like different arachnids, which spend most of their time immobile of their net, leaping spiders are out and about, searching prey and courting mates. Jakob is fascinated with what goes on inside their sesame-seed-size brains. What issues to those tiny spiders? 

For clues, Jakob watches their eyes, significantly their two principal ones, which have high-acuity coloration imaginative and prescient on the middle of their boomerang-­formed retinas. She makes use of a software advanced from an ophthalmoscope that was specifically modified to review the eyes of leaping spiders greater than a half-century in the past. Generations of scientists, together with Jakob and her college students at UMass Amherst, have constructed on this design, slowly morphing it right into a mini movie show that tracks the retinal tubes shifting and twisting behind the spiders’ principal eyes as they watch. 

A spider is tethered in entrance of the tracker whereas a video of, say, a cricket silhouette is projected by way of the tracker’s lenses into the spider’s eyes. A beam of infrared mild is concurrently mirrored off the spider’s retinas, again by way of the lenses, and recorded by a digital camera. The recording of these reflections is then superimposed on the video, displaying precisely what the spider was . Jakob discovered that virtually the one factor extra attention-grabbing to a leaping spider than a possible cricket dinner is a black spot that’s rising bigger. Might it’s an approaching predator? The spider’s lower-resolution secondary eyes catch a glimpse of the looming spot within the nook of the video display screen and immediate the first eyes to shift away from the cricket to get a greater look.