Foxes may confuse predators by rubbing themselves in puma scent

A smelly solution?

Maresa Pryor/Lightwave Photography Inc./NGS Creative

By Richard Gray

They have a reputation as cunning creatures, and some foxes appear to be living up to it as masters of disguise.

Gray foxes living in the mountains of California have been filmed deliberately rubbing themselves in the scent marks left by mountain lions.

They may be using the scent of the big cats, also known as pumas or cougars, as a sort of odour camouflage against other large predators such as coyotes.

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Coyotes often kill gray foxes, which are half their size, to reduce competition.

Max Allen, an ecologist at the University of Wisconsin at Madison, had been studying pumas visiting sites known as “community scrapes”, where males leave scent “signposts” to communicate with others.

Surprise visitors

He was surprised when remote cameras set up to monitor the mountain lions revealed foxes also regularly visiting these sites.

Analysis of footage taken over four years at 26 different sites revealed the foxes were rubbing their cheeks on bits of ground that had been freshly marked by the mountain lions, often within hours of a big cat’s visit.

“The foxes rub very specifically on the areas where the pumas mark,” says Allen. “Coyotes are very reliant upon smell when hunting and are much bigger than the foxes. The foxes have a hard time fighting back, so they use this to give themselves a chance to escape.”

Allen and his colleagues found 92 out of 903 documented visits by foxes involved cheek rubbing. And 85 per cent of the foxes that exhibited this behaviour did so on spots where pumas had deposited their scent. The team did not see any similar behaviour from coyotes or bobcats, which also visited the sites far less frequently than the foxes.

Many animals rub their cheeks and bodies on stones, trees and the ground to leave their scent behind. Allen’s video footage, however, showed the foxes rubbing themselves in the puma scrape five times more often than they did on shrubs or unmarked ground at those sites.

This suggests they were focused on applying puma scent onto themselves, rather than depositing their own scent.

Escape strategy

There are various reasons why foxes might do this. But Allen’s team says that predator avoidance seems the most likely hypothesis and is worth exploring further.

“Gray foxes climb trees to avoid predators,” says Allen. “In many cases, they probably only need a few seconds’ hesitation from a coyote for them to get up a tree. Smelling like a puma might give them that time.”

But there may be another explanation, says Steve Harris, an ecologist who studies foxes at the University of Bristol in the UK.

“Foxes use their saliva as scent and have glands in the region of the lips,” he says. “My impression is that the gray foxes are stimulated by the strong odours left by the pumas and are depositing their own scent.”

Allen and his colleagues hope to use tags on some gray foxes to study whether foxes that have rubbed themselves in puma scent are more likely to survive predation.

Journal reference: Journal of Ethology, DOI: 10.1007/s10164-016-0492-6

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