20 December 2007

Squirrels Use Snake Eau de Cologne

by Kate Melville

Animal behaviorists have observed California ground squirrels and rock squirrels chewing up rattlesnake skin and smearing it on their fur to mask their scent from predators.

Reporting their observations in the journal Animal Behavior, the researchers noted that adult female squirrels and juveniles apply snake scent more often than adult males, which are less vulnerable to predation by snakes. "The scent probably helps to mask the squirrel's own scent, especially when the animals are asleep in their burrows at night, or to persuade a snake that another snake is in the burrow," said researcher Barbara Clucas, from the University of California - Davis.

The squirrels are not limited to the use of shed snake skins, added co-researcher Donald Owings. "They also pick up snake odor from soil and other surfaces on which snakes have been resting, and use that to apply scent. Other rodents have been observed using similar behavior," he explained.

In earlier work, Owings' lab had found that squirrels can also heat up their tails to send a warning signal to rattlesnakes (which can "see" in the infrared); assess how dangerous a particular snake is based on the sound of its rattle; and display assertive behavior against snakes to deter attacks. "It's a nice example of the opportunism of animals," Owings said. "They're turning the tables on the snake."

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Source: University of California - Davis