Some of the most destructive wildfires in Southern California history killed 10 people, with more than 5,300 structures destroyed or damaged from the Palisades fire in Pacific Palisades and Malibu, and 7,000 more in Altadena, Sierra Madre and Pasadena from the Eaton fire.

The fires in Los Angeles County that have raged since Tuesday have forced evacuations of about 180,000 people, many who are staying with family or friends, while others sleep in motels, their cars or temporary shelters.

Alongside this unprecedented human tragedy are nearby wildlife — silent victims who have also evacuated, fleeing tall flames and choking smoke with no place to go.

Scientists, nonprofit animal groups and environmental organizations could not yet count the toll on the animals, but they are fairly certain the effect on all sorts of critters, from mountain lions in the Santa Monica Mountains to rare frogs in forest rivers, will be significant.

Wildlife crossing

“This will impact everything from mountain lions to monarch butterflies,” said Beth Pratt, California regional executive director for the National Wildlife Federation and founder of The Wildlife Crossing Fund on Friday. “It will be a tough go for people, and wildlife. My heart is breaking.”

In Altadena, north of Pasadena, where the wind-whipped fire destroyed rows of homes and businesses in a scene that some described as looking like a bomb went off, a baby deer was caught on video running down a street, at one point stopping and turning to look for safety.

The viral image of a helpless deer fleeing flames underscored the crushing sadness of the entire situation for both humans and wild animals.

This is true especially in Altadena, a unique, unincorporated county community near the San Gabriel Mountains that mixes suburbia with a touch of rural life.

“The Altadena foothills community are where people and wildlife are neighbors,” said Barbara Goto, director of operations for the Arroyos & Foothills Conservancy. “They might own chickens, llamas or horses. People live up there because they love wildlife. They love that environment.”

The conservancy has preserved close to 100 acres of open space in Altadena, Glendale and Pasadena. Goto said she’s almost sure two preserves have been blackened by the Eaton fire.

For those who see wildlife, Goto recommends calling the local humane society and also placing bowls of water outdoors to support them.

“You may see animals fleeing affected areas; they are most likely exhausted and scared,” the group wrote in an email to members.

The first set of injured animals from the fires was transported from the Pasadena Humane Society to the Wetlands and Wildlife Care Center in Huntington Beach on Thursday afternoon.

The center reported receiving: two male peafowl, two opossum, and a newborn racoon who could not be saved.

“The stress of losing its mother and the stress of the fire was too much for the baby,” the center reported.

Another TV news video captured a cougar cub with a sibling and its mother fleeing the Palisades fire by crossing Topanga Canyon Boulevard unharmed. Most experts said they are escaping with their lives and also checking out better hunting habitat.

Lions will explore new territory that has more cover, making it a safer place to hunt. But this has drawbacks because it can bring them face to face with other hungry lions.

“By going into overlapping areas there is a risk of mountain lions killing each other” over territory, said Tiffany Yap, senior scientist with the Center for Biological Diversity.

The trio most likely came from the Santa Monica Mountains, home to about a dozen mountain lions under study by the National Park Service. This included the beloved Hollywood Cat, P-22, who crossed freeways to live for 10 years in Griffith Park. P-22 died from several factors, including being hit by a car.

These big cats are isolated by a prison of freeways and roadways; they can’t find mates and face extinction. Many have died from eating carrion like squirrels that have ingested rat poison, or are killed by vehicle strikes while trying to cross to find a mate or food.

This cougar family went from one dangerous situation, a raging fire, to another, a busy thoroughfare. The fires add more stress to an almost unlivable situation, experts said.

“I’m just glad they made it safely across,” said Pratt. “Mountain lions will either be lucky and cross the road safely. Or not.”

Scientists studied how recent fires, which are continuing to get larger and hotter, are affecting local wildlife.

The 2018 Woolsey fire that started in the Santa Susana Mountains and spread from L.A. County to Ventura County was huge, killing three people and burning through 96,949 acres while destroying 1,643 structures.

Pratt said two mountain lions died in that fire. One expired two weeks later from starvation.

“He couldn’t get out of the fire zone,” she noted.

A mountain lion whose paws were burned in the 2020 Bobcat fire in the Angeles National Forest was found wandering in a nearby backyard of someone’s home, said Yap.

She was rehabilitated by UC Davis veterinarians using tilapia skin as a healing patch, she said.

“She was released back into the wild,” Yap said.

Pratt is leading the building of the Wallis Annenberg Wildlife Crossing in Agoura Hills. The massive wildlife bridge is under construction and set to open in early 2026. It will span 10 lanes of the 101 Ventura Freeway at Liberty Canyon Road and connect cougars living in the Santa Monica Mountains to a vast rural territory of open space to the north.

Badgers, deer mice and ground squirrels make burrows and go underground for protection during a fire. Snakes and lizards find safety living under logs, Yap said.

But Yap’s group is very worried about the survival of the mountain yellow-legged frog, an endangered species that lives in streams in high elevations in the San Gabriel, San Bernardino and San Jacinto mountains.

After the current spate of fires, stream slopes may become denuded and vulnerable to landslides from rainstorms.

Mudslides can wash into their habitat, causing them to die or no longer procreate, Yap said.

“Some of these wildfires could impact their long-term survival,” Yap said.

Bird survival

Some bird species, such as woodpeckers, can find a charred tree that’s still standing and use it for their nesting spot, said Chris Spurgeon, program chair for Pasadena Audubon.

“A dead tree can turn into a condo and actually increase habitat,” he said.

Other birds in Eaton Canyon, such as wrentits, scrub jays and turkey vultures may thrive after a firestorm, he said. Most birds can fly away from flames. Turkey vultures may be seen hovering over the Eaton Canyon fire zone looking to snack on deer carcasses, he said.

“They have a super keen sense of smell,” Spurgeon said.

Two weeks ago, Spurgeon went to look for great-horned owls in Eaton Canyon. On Friday, he was thinking they escaped the fire but may have difficulty reproducing come spring, bird breeding season. Owls will look for green, tall trees elsewhere to build their nests.

“They may have escaped this fire and found other areas to live and hunt,” he said. “It’s quite likely they will skip breeding this year and wait another year to raise a family.”

This could reduce their population next year, he said.

Studies during a wildfire in Washington state found a correlation between smoke and bird health.

“Birds are more likely to be vulnerable to wildfire smoke,” said Olivia Sanderfoot, an interdisciplinary ecologist at UCLA’s Department of Ecology & Evolutionary Biology.

It is because they need to breathe in air more deeply, in order to fly, she said.

“Birds use air sacs around their lungs and they get double the amount of oxygen with each unit of air they take in,” she explained. “This is important because birds fly. Birds are excellent breathers to support the way they exist.”

Unfortunately, birds are more vulnerable to the particles, known as PM2.5, and tiny metals, found in the air of a wildfire.

Humans are also very susceptible to lung and heart issues, asthma or even heart attacks from breathing in smoky air.

Studies show smoke from fires was connected to a drop in bird body mass, changes in migration patterns and bird songs, she said.

“We found smoke was linked to a decline in bird song and bird calling,” she said.

One scientific article said bird watchers noticed an “eerie silence” in a wooded area filled with wildfire smoke. The studies point out that this nascent research underscores emerging evidence that says smoke from a fire is damaging to animals and humans.

“Everywhere we look we are finding the effects of smoke,” Sanderfoot said.