Squirrels as Models for Human Behavior? Indeed!
Posted by dlende on July 7, 2010
A delightful article on squirrel behavior, biology, and sociality today highlights just how great a model squirrels can be for some true comparative research. Here’s another species with phenomenal elasticity, good learning and sociality, and even specialized brain and body parts!
Behind the squirrel’s success lies a phenomenal elasticity of body, brain and behavior. Squirrels can leap a span 10 times the length of their body, roughly double what the best human long jumper can manage. They can rotate their ankles 180 degrees, and so keep a grip while climbing no matter which way they’re facing. Squirrels can learn by watching others — cross-phyletically, if need be.
In the acuity of their visual system, the sensitivity and deftness with which they can manipulate objects, their sociability, chattiness and willingness to deceive, squirrels turn out to be surprisingly similar to primates. They nest communally as multigenerational, matrilineal clans, and at the end of a hard day’s forage, they greet each other with a mutual nuzzling of cheek and lip glands that looks decidedly like a kiss.
The gray squirrel is diurnal and has the keen eyesight to match. “Its primary visual cortex is huge,” said Jon H. Kaas, a comparative neuroscientist at Vanderbilt University, A squirrel’s peripheral vision is as sharp as its focal eyesight, which means it can see what’s above and beside it without moving its head.
“We’ve seen seeds that were recached as many as five times,” said Dr. Steele. The squirrels recache to deter theft, lest another squirrel spied the burial the first X times. Reporting in the journal Animal Behaviour, the Steele team showed that when squirrels are certain that they are being watched, they will actively seek to deceive the would-be thieves. They’ll dig a hole, pretend to push an acorn in, and then cover it over, all the while keeping the prized seed hidden in their mouth. “Deceptive caching involves some pretty serious decision making,” Dr. Steele said. “It meets the criteria of tactical deception, which previously was thought to only occur in primates.”