Why do squirrels rub snake scent on themselves, and what does it actually do?

Most prey animals shun the scent of their predators. The discovery of some ground squirrels deliberately covering themselves with the scent of a predator surprised many scientists. In the case of California ground squirrels and rock squirrels, researchers observed that the animals actually chewed on pieces of shed rattlesnake skin and applied the scent on their fur.

At first, the action seemed to be risky or even irrational. However, scientists think that the animals could be practicing chemical camouflage by applying the snake's scent to their body. The theory is fairly simple, although very unique. A squirrel that smells less like a prey animal and more like the general snake scent in its surroundings will confuse the rattlesnake while it searches for prey. It has come to be one of the most surprising examples of prey animals adapting to their predators.

The bizarre activity of the squirrels


This phenomenon was detailed in a research article published in the journal Animal Behaviour. The scientists observed that California ground squirrels and rock squirrels actually chewed on shed rattlesnake skins and applied the scent on themselves. The behavior was termed a "novel anti-predator behavior" by the scientists who noted that it could decrease the probability of the squirrel being detected by snakes.

Significantly, the contact between the squirrel and the snake skin seemed intentional rather than accidental. The University of California, Davis, later stated that squirrels use snake scent to cover up their odor from predators. This is important as it alters the way scientists understand the behavior. Instead of signaling a danger, the scent could be used as a form of camouflage.

How the scent of a predator can help prey

Using the scent of a predator is counterintuitive since prey animals are supposed to avoid predator odors. However, animal behavior experts note that animal scents have multiple roles depending on the circumstances.

According to a government report on olfactory camouflage, some animals such as ground squirrels use predator odors for strategic reasons. Some animals use the environment odor to decrease their detectability. Essentially, the squirrel would smell less like a squirrel and more like part of the snake's environment.

Scientists find this significant since rattlesnakes depend largely on chemical signals while hunting. It means that when the signals get confused or diluted, the predator will have difficulty identifying the prey in its environment. The review on predator odor biology also mentioned that olfactory camouflage reduces the information gathered by the predators from scent.

There are many anti-snake defenses used by squirrels

It is just a small component of a wide range of defenses employed by the squirrels. California ground squirrels are famous for the sophisticated anti-predator strategies they adopt against rattlesnakes. They include defending burrows, harassing snakes, and issuing warning signals whenever a predator approaches.

For instance, squirrels were found to be able to heat and wave their tails in such a way that interferes with the rattlesnakes' heat sensing abilities. These strategies have developed through long-term interactions between the squirrels and the snakes.

According to scientists who wrote an article on squirrel venom resistance and behavior physiology, the squirrel-rattlesnake relationship represents a highly specialized predator-prey system. The above explanation shows why chemical camouflage easily becomes a part of the system.

The squirrel’s behavior is not random

Scientists discovered that the scent strategy was mostly exhibited by squirrel populations that live around rattlesnakes. The phylogenetic analysis conducted by the Behavioral Ecology and Sociobiology found that the application of rattlesnake odor among several squirrel species correlated with areas where squirrels were under historical snake pressure. However, such results could not be found for any other predator scents.

This indicates that the evolution of the behavior is specific to rattlesnakes and is not the result of random grooming behavior. It is also known that ground squirrels can distinguish various predator dangers quite elaborately. Studies have shown that they behave differently when reacting to rattlesnake sounds or danger signs. This proves that their reactions are intentional and deliberate, and not accidental.

What the behavior tells us about animal survival

The squirrel-snake case demonstrates how complicated animal survival methods can become over millions of years of evolution. Instead of using just one mechanism for defense, squirrels employ several mechanisms simultaneously. Some of them are visual, some of them auditory, tactile, or chemical.

Chemical camouflage is one more weapon in the arsenal of squirrel survival techniques. Experts warn against assuming that the smell makes squirrels invisible to predators. The smell could only have the effect of reducing their detection or making it more difficult for the snakes to recognize them as prey.

Even a slight advantage would make a difference in the predator-prey relationship that evolved over thousands of generations. It is this very reason that makes the behavior so intriguing to researchers. It demonstrates how animals can use environmental chemicals strategically.