A California ground squirrel is on the lookout. A new study shows that some of the rodents use snake skin to mask their scent to predators.
Credit: U.S. Fish and Wildlife Service
Rattlesnakes often chow down on unwary squirrels, but new research shows the rodents fight back by eating, rubbing and even bathing themselves with pieces of discarded snake skin.
The reptilian musk helps California ground and rock squirrels mask their natural scent and thereby avoid detection from their slithering nemeses.
"It's a nice example of the opportunism of animals," said psychologist Donald Owings at the University of California Davis. "They're turning the tables on the snake."
Owings co-authored the study with Barbara Clucas, a graduate student in animal behavior, and others in a recent issue of the journal Animal Behavior.
Clucas saw squirrels picking up pieces of shed snakeskin, chewing it and then licking their fur — a trick that can fool snakes, which have poor eyesight but an advanced sense of smell.
The resourceful squirrels also bathe in soil that snakes have rested in.
Owings said the newfound tricks are just a few in the squirrel's snake-fighting arsenal; the rodents can also heat up their tails to warn rattlesnakes, as well as gauge threat level based on a snake rattle's sound. These behaviors are learned, Owings said, but if they fail, squirrels have also evolved biological resistance to snake venom, other studies have found.