Key Findings
According to research from UNH, black bears may shield gray fox from predators like coyotes, allowing smaller carnivores to co-exist. This is one of the first studies to show how black bears provide a buffer to support the survival of other carnivores.
About the CO-Author
Rem Moll, Assistant Professor of Natural Resources and the Environment
Contact information: Remington.Moll@UNH.edu, 603-862-3054, Moll Lab website
This research first published in Oecologia.
Researchers: R. Moll, P. jackson, b. wakeling, c. lackey, j. beckmann, j. millspaugh, r. montgomery
Bears are known to be protective of their cubs, but new research from the University of New Hampshire shows that black bears may also play a role in shielding gray foxes from predators like coyotes. These smaller carnivores compete with the foxes for food and space. This study is one of the first to demonstrate how black bears can help other smaller carnivores safely coexist.
Lead author of the study, Rem Moll, explains that even though black bears and coyotes are the two most common carnivores in North America, we are still learning about how they impact the ecosystems around them. The unique trait of hibernation among black bears, where they disappear for half a year, can shift animal habits in the ecosystem.
“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 study published in the journal Oecologia took a closer look at the hierarchy of carnivores to see if a major life trait like hibernation had a significant effect. Researchers tracked and monitored the top species of carnivores in the western part of Nevada near Lake Tahoe. They found that in summer, gray foxes stayed close to areas populated by black bears, which appeared to provide a top-down buffering effect, helping to protect the gray foxes from coyotes. However, in 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 foxes moved out.
“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,” says 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 found that the top carnivore, black bears, provided a shield for the gray foxes from competition with coyotes. However, this “bear shield” was only seasonal, disappearing when the bears hibernated. Moll notes that this work suggests fear is important in defining the species roles in the ecosystem. The researchers believe that these instinctual actions could be a very common dynamic in any area where black bears, gray foxes, and coyotes coexist, even though this study was done near Lake Tahoe, where black bears were nearly extinct a few decades ago.
Funding for this study was supported by the Nevada Department of Wildlife $3 Predator Fee Program and statewide game management support.
