Home Science Wildfire Brought Wolves Back to Southern California after 150 Years

Wildfire Brought Wolves Back to Southern California after 150 Years

0
Wildfire Brought Wolves Back to Southern California after 150 Years

[ad_1]

Years of drought and rising temperatures have turned California into a tinderbox. Since 2020 millions of acres have burned across the state. The fires have killed forests and people. But fire also brings life: California’s blazes have renourished soil, supercharged grass growth and set the stage for a top predator to reclaim part of its historical stomping grounds.

After the smoke cleared on 2021’s Windy Fire, a pack of wild wolves settled in the burned-out area just three hours north of Los Angeles. It’s the first time in about 150 years that gray wolves have roamed this part of the Golden State.

“If you walk through a burned landscape with lots of dead trees, you’ll be surprised by the vibrant life which springs from the ashes,” says Andrew Stillman, an ecologist at the Cornell Lab of Ornithology.

Wolves once ranged across all of North America, from Arctic Alaska to Mexico—and even east to present-day Manhattan. But as settlers swarmed the continent, development, hunting and the fight for space dramatically reduced wolves’ numbers. Climate change and still relentless development are now putting pressure on the few that remain.

Today most wolves in the U.S. occupy scattered pockets in a few Western states—mainly Alaska, Wyoming, Montana and Idaho—after several dozen were reintroduced into Yellowstone National Park in the mid-1990s. In the early 2000s a small number of wolves traveled from Canada into Oregon, and in 2011 an adult male first crossed the border into California. A couple of dozen wolves now live in the remote, mountainous northeastern corner of the richest and most populous state in the U.S.

California’s Department of Fish and Wildlife confirmed the wolves’ expanded presence this past August by evaluating scat, photographs and videos. That evidence showed at least one adult female and four cubs were living in Sequoia National Forest. DNA tests also revealed the adult female was a direct descendant of that first wolf that crossed into California more than a decade ago. The female traveled about 200 miles from the nearest known wolf pack, scaling the mighty Sierra Nevada mountains.

Why did the wolves move so quickly into a burned landscape? When fires kill trees, more sunlight is able to reach the blackened soils; this stimulates dormant plants such as grasses to sprout. The nutritious grasses attract deer and other species, offering wolves a buffet.

One of the wolves sighted in Sequoia National Forest
One of the wolves sighted in Sequoia National Forest, the first to dwell in Southern California in about 150 years. Credit: Michelle Harris

Additionally, “it’s much easier to hunt in an open forest,” notes William McDarment, a former firefighter who now works as a rancher on the Tule River Reservation. The return of the predators has also led to some conflict with humans: McDarment and other reservation residents say wolves have killed their livestock. And people have reported tracks and suggested that more wolves than officially documented may be dwelling in the area.

Burn scars additionally provide good den sites for wolves when they give birth because an open forest provides better views of intruders such as bears, coyotes or other predators that could threaten the cubs.

“There are other examples of wolves using fires as habitat, both in Montana and outside of the U.S.,” says Ellen Whitman, a forest fire research scientist at Natural Resources Canada. And wolves in Alberta also “preferentially select habitats that had burned or were near to burns,” she points out, because of the moose and other prey that flock to such spots.

Animals besides wolves and ungulates thrive in places where wildfires have blazed through as well. “Black-backed Woodpeckers are almost fire-dependent and are well-known for the tendency to nest in burns,” Whitman says, adding that beetle grubs and other food are easily available there. And burn zones are a haven for pyrophilous (fire-loving) insects, which “use the scent of smoke to navigate toward burned trees, where they lay their eggs,” says Olivia Sanderfoot, an ecologist at the University of California, Los Angeles.

Trees can also benefit. “The jack pine produces serotinous cones that are sealed shut with resin and only open when heated,” Sanderfoot says.

Such results of wildfire are not just a North American phenomenon. African vervet monkeys are known to expand their ranges and become more efficient at foraging after savanna blazes because hunting insects is much easier on grasslands when there’s very little grass for the arthropods to hide in.

Of course, there’s such a thing as too much fire—even for species with an affinity for burned landscapes. Stillman, the Cornell ecologist, says that Black-backed Woodpeckers prefer the charred trees they nest in to be next to leafy living trees, which help protect and conceal the birds’ young. Fires in and around California’s Yosemite National Park underscore this balance: After the 2013 Rim Fire burned more than 250,000 acres, there was ample prime woodpecker habitat. But a year later the King Fire burned another 97,000 acres nearby. When these areas were studied in 2014 and 2015, very few woodpecker nests were found.

Though such species have adapted to fire, and low-intensity fire is necessary for the health of these ecosystems, today’s megafires—fueled by climate change and decades of humans suppressing smaller blazes, allowing brushy tinder to build up—can burn much hotter and easily rage out of control. That can destroy some of the seeds of even fire-dependent trees, prolonging recovery. And treeless soil is more prone to flash floods and erosion.

As global temperatures rise and as hotter, drier forests build fuel, “a warming climate in California is likely to bring with it more chances for those large, catastrophic fires,” says Morgan Tingley, a U.C.L.A. ecologist.

What that means for wolves and other species may be a mixed bag. “Wolves are generalists. They go from Arctic tundra all the way down to forests,” says Karen Hodges, an ecologist at the University of British Columbia’s Okanagan campus, who has studied fire-related issues since 2002. “As long as they have prey, they’re capable,” she says, meaning that the new pack is likely safe for now, even in crowded California.

But as for the broader outlook for these ecosystems, “it’s bleak,” she says. “There are about 1,000 animal species directly threatened by extinction [worldwide] because of the changes in fires.” Whole forests could be lost if it’s too hot or dry for seeds to grow or if fires repeatedly sweep through.

While no one can control today’s trajectory, allowing small wildfires to burn naturally could help restore the balance, says Rod Linn, a senior scientist at Los Alamos National Laboratory. “That’s an integral part of sustainability,” he adds, but it’s not without risks. “Some people still think fire is always bad—people who lost loved ones or their houses. It’s understandable. But we should allow more low-intensity fires to persist so they can do their job. It’s a political hot potato if you decide to not put it out, and it burns down homes. But how do we allow fire to reestablish itself in a safe and responsible manner? That’s the big question.”

[ad_2]

LEAVE A REPLY

Please enter your comment!
Please enter your name here