UNH: Black Bears May Protect Gray Fox Population

Researchers at the University of New Hampshire say that black bears may be shielding the gray fox species from predators like coyotes.

Coyotes compete with foxes for food and space, and this research is one of the first to show how black bears might provide a buffer to allow other, smaller carnivores to safely co-exist.

“Even though black bears and coyotes are the two most common carnivores in North America, we’re still learning how they affect the ecosystems around them,” Rem Moll, assistant professor of wildlife ecology and lead author of the study, said in a statement.

Moll said bears are unique because they hibernate, so they disappear for half the year, which can shift animal habits in the ecosystem.

In the study, published in the journal Oecologia, researchers took a closer look at the hierarchy of carnivores to see if a major life trait, like hibernation, had a significant effect.

In the western part of Nevada, near Lake Tahoe, researchers tracked and monitored the top species of carnivores, according to a press release from UNH Media Relations.

That included black bears - which are the largest and most dominant species - followed by coyotes, bobcats, and gray foxes.

Researchers found that in the summer, gray foxes stayed close to areas populated by black bears.

In the winter, when bears were hibernating, this pattern reversed and coyotes were three times more likely to move into the now-vacant bear territories and the gray fox, no longer secure by the presence of the black bear, moved out, according to a press release.

This pattern suggests that the top carnivore - black bears – provided a shield for the gray fox from coyotes. But this “bear shield” was only seasonal, disappearing when the bears hibernated.

“In our field of research, there is something called the 'landscape of fear' – the idea that there is a pecking order and that both predators and prey will change their behavior to avoid getting killed,” said Moll. “For decades this was overlooked, so there aren’t a lot of studies showing the connection between black bears and coyotes – two of the most common carnivores in the U.S. - but this work suggests that fear is important in defining the species roles in the ecosystem.”

The researchers say even though this study was done near Lake Tahoe, where black bears were nearly extinct a few decades ago, they believe these instinctual actions could be a very common dynamic in any area where black bears, gray fox and coyotes co-exist.

Contact Managing News Editor Kimberley Haas at Kimberley.Haas@townsquaremedia.com.