Where Do Wildlife Go When Fires Strike?

If you had told me a year ago that we would live through the largest wildfire season in California’s history in 2020, I wouldn’t have believed you. Already, over 4 million acres of the state have burned — more than five times the five-year average. To be honest, it’s hard to imagine but, then again, much of 2020 has felt that way to me.

Maybe I shouldn’t be so surprised? For decades, science has warned us that a warming climate will create larger, more frequent, more destructive fires. And, in fact, the number of extreme fire days in the state has already doubled since the 1980s. Locally, this means a longer, hotter late summer and fall which results in a longer fire season with fires that can burn much hotter, spread faster and consume more than ever before. Clearly we are living in the “new normal,” but these changes are happening faster than most of us can fully comprehend.

Lightning in mid-August 2020 ignited fires across the Bay Area. The CZU Lightning Complex spread through the heart of our local redwoods, damaging all of Big Basin State Park, Little Basin Campground and portions of Butano State Park and Pescadero Creek County Park. 

A Natural Ingredient

Only now is the media beginning to cover the fact that in the United States, we have actively suppressed fire on the landscape for over 100 years. Prior to that, fire was a natural part of many ecosystems. For thousands of years, the Indigenous people of California have used fire as a way to cultivate the land, sustain their communities, stimulate their crops and prevent large blazes by reducing fuel, such as dry grasses and leaf litter, with frequent, small, hand-set burns.

But the scale at which we’re actively burning — what’s now commonly referred to as “prescribed fire” — has dramatically changed. To put things in perspective, before European settlement, somewhere between 5 and 10 million acres would burn each year.

Escape or Hide, The Only Options

California has dozens of ecosystem types, and locally, these landscapes are home to myriad animals that are iconic and treasured by many of us. From stately pumas to colorful snakes, western fence lizards, rabbits and woodpeckers. As a wildlife enthusiast I’ve been worried about their wellbeing as we watched the CZU Lightning Complex burn through the heart of the Santa Cruz Mountains. But conversations with two local experts helped set my mind at ease a little.

Chris Wilmers, a Professor in the Social Sciences Division of UC Santa Cruz (UCSC) had some good news to share. He heads the Santa Cruz Puma Project — a partnership between UCSC and the California Department of Fish and Wildlife. Using radio telemetry collars on mountain lions, they collect data on the animals’ movements in order to answer important questions about how they live, their habitat needs and the important passages for lions within and between the Santa Cruz Mountains and surrounding area.

“Fire is a natural process that these animals are well adapted to,” he said. And early indications from the CZU Lightning Complex fire are that the three collared mountain lions with territory in the burn area have survived. Welcome news, to be sure!

But not every species has such an optimistic story. The old-growth Douglas fir within this redwood forest — home to the elusive and endangered marbled murrelet — suffered greatly. We are concerned about how this potential loss of habitat will impact the birds.

Wes Gray, a long-time natural resource manager for California State Parks in the Diablo Range, where the massive 396,624-acre SCU Lightning Complex fire is burning, further quelled my anxiety over the loss of wildlife to fire. “All the animals that can get out of the way — mountain lion, bobcat, coyote, deer and birds — they just run away from the fire, simple as that,” he said. “And what can’t run will hide, mostly burrowed underground.” It’s not that every animal made it out of these fires – surely many have perished — but those that had the means to escape certainly did so.

For birds, fire during the nesting or fledgling season is the most dangerous. Because our recent fires were past this season for most local birds, they were likely able to escape ahead of the fires. Much like many of us in the Bay Area though, unfortunately birds may suffer damage to their notoriously sensitive lungs from smoke.

With smaller ground animals, escape may have been trickier. In areas that burned extremely hot, burrowing into the soil may not have been sufficient to save them. But in lightly to moderately burned areas, burrowing into networks of underground tunnels to escape the worst of the fire will have likely kept them safe from harm.

Reports from POST staff that have visited the burned areas are that they have come across several dead animals, and in general the forest feels notably quieter; the woodpeckers are out in force, but it seems that there are fewer other birds, and the woodrats’ nests which dotted the forest everywhere are gone — completely gone.

How it Burns Defines What Survives

The severity of the fire — how hot and fast it burns — is the greatest indicator of its destructiveness on a landscape and the animals that live there. The larger, fast-moving fires burn so intensely they incinerate everything in their path.

“Fires that hot can crash an entire ecosystem,” Gray said, meaning that a very hot fire can actually burn into and beneath the soil, destroying the micro-organisms, seeds and other living creatures that can rebuild an ecosystem literally from the ground up. When this happens, it takes decades for the land and the animals to recover.

That’s why resource managers like Gray look for signs of lower intensity fires that help increase the “patchiness” of a landscape and create a wider variety of microhabitats.

“We’re always hoping to see a mosaic of unburned green sections, so there’s still food available to forage — still some refuge,” Gray said. Having these patches of green means that different habitats will survive after a fire to support the food and shelter needs of a range of species and the ecosystem as a whole.

While we are still assessing the impacts, it appears that fires in both the Santa Cruz Mountains and the Diablo Range burned with varying intensity across the landscape.

“We’re always hoping to see a mosaic of unburned green sections, so there’s still food available to forage — still some refuge,” Gray said.

In August, a large portion of Henry W. Coe State Park in Morgan Hill burned in the SCU Lightening Complex fire. According to Gray’s analysis of the damage to habitat there, the majority of this fire burned at a low intensity, primarily burning grass and brush while not burning the tree canopies.

According the Gray, “there were some sections where the topography increased the fire behavior and a higher percent of the vegetation burned, including oaks and pines. Overall this burn was good for the ecology of the park. It burned very similar to how a planned prescribed burn would. There was a lot of consumption of downed trees and other fuel loads, while not burning so hot as to damage seed banks or consume old heritage trees.”

Wins and Losses

It is very difficult to estimate the number of animals that die in wildfires. As a result of the immense fires in Australia in 2019 and 2020, scientists had to assemble over 100,000 studies and then extrapolate that data to arrive at a staggering estimate of the loss of animal life.

But here’s a hopeful thought: There is no documented case of a fire — or even something as severe as the Mount St. Helens eruption — wiping out an entire population or species. However, wildfires do spark a succession of changes as life recolonizes or reclaims the landscape. So many things will impact how our lands and wildlife recover from the recent fires. It’s a lot of “if-then” scenarios to which only Mother Nature knows the answers.

As I ended my conversation with Wilmers, I took solace from his parting comments. “There’s going to be a whole lot of food for deer out on the landscape as things re-sprout,” he said, “and that means potentially more deer, which is a good thing for mountain lions.”

It’s clear we’ve witnessed a profound transformation within this landscape, one that will take time to fully understand. And while the loss of life is heartbreaking, I take strength in the natural resilience of California’s wildlife and natural systems.

One thing is for certain, life will return.