A group of researchers has recently published a study in the journal Nature Communications in which they explained that the raccoon population could be controlled by the use of fear.

Raccoons have become a menace in the British Columbia, Canada since they got the top position in the circle of life of the area. Larger predators like bears, wolves, and cougars have disappeared after being killed by humans and left the area at the mercy of the raccoons.

Raccoons are famous for their capabilities of causing extreme damages wherever they are. Large predators were able to control the raccoon population over the Gulf Islands in British Columbia, but after their disappearance, raccoons did exactly what they were expected: caused trouble and also decimated the crab, fish and worm populations.

Photo: NatGeo
Photo: NatGeo

Bears, wolves, and cougars meant a threat to humans so many of them were killed and others were relocated at a more safe distance. After raccoons were free to do as they pleased, not only the crab, fish and worm population is decreasing drastically, but raccoons leave the remaining parts of their feast anywhere they want, directly affecting the ecosystem of the islands.

A solution was needed

Justin Suraci, an ecologist at the University of Victoria, spent several years on the Gulf Islands on the study which was basically a sounding project. He and his colleagues found that the sound of a dog barking scared raccoons and they left the place immediately. Currently, domestic dogs are the only natural predator existing in the area, so they would probably be the only solution to the raccoon problem.

Suraci explained that larger predators played an important role in the ecosystem in which they controlled smaller predators by causing terror. Raccoons were kept under control since they were scared of the big, scary animals, and they were kept from wandering around.

According to the researchers, fear balances the ecosystem. It makes animals respect the natural order of things. They spend less time eating and more time protecting themselves avoiding to get eaten. Since larger predators could not be reintroduced, researchers experimented with sounds of mad barking dogs to scare the raccoons.

The experiment and its results

Researchers installed speakers along two parts of the coastline and played mad dogs barking sounds. They also installed a camera to capture the raccoons’ reactions.

After several months of doing this, results showed that the hunting of raccoons decreased by 66 percent and stopped coming out on the coastline. They also became more alert and only went out in the search for food.

“Following the month-long large carnivore playbacks, there were 97% more intertidal crabs, 81% more intertidal fish, 59% more polychaete worms and 61% more subtidal red rock crabs compared with after the non-predator playbacks”, researches wrote at the results section of their study.

Raccoons did not have to actually see dogs take protective measures. Just the sound was enough to get good results. Maybe, actual dogs could also help in controlling the raccoon population in the islands.

Source: Journal Nature