Nature Takes a Post-Fire Walk on the Wild Side

The skies above charred hillsides are filled with hawks, many circling in places, such as the coastline, they normally avoid.

On the ground, wood rats the size of small cats are invading houses that withstood last autumn’s brush fires, nesting in garages, pantries and cars.

And in creeks within the fire-ravaged Santa Monica Mountains, tree frogs, normally a pale beige or gray, have turned as black as their burnt surroundings.

Across Southern California, wildlife experts and even casual observers cannot help noticing the ways the wildfires have changed the behavior of animals. Although many animals inevitably were killed, the survivors have quickly and relentlessly demonstrated how life reaffirms itself.

To people living in or near the fire zones, that fierce will to survive shows up in ways riveting and revolting--from the sudden appearance of brilliantly hued mountain bluebirds that blanketed Laguna Canyon after the fires to the beady-eyed wood rats gnawing their way into hillside homes.

“It may seem eerie or weird to some people,” said ecologist Sean Manion of the Topanga-Las Virgenes Resource Conservation District, “but in actuality it’s a pretty normal event following fire.

“Fires are a naturally occurring phenomenon in the mountains here,” he noted. “It’s been going on for thousands of years.”

A post-fire rat invasion is so typical that the Federal Emergency Management Agency’s disaster recovery center in Malibu offers leaflets on the prevention and control of rodent infestations. Just like human fire victims, the rats become homeless when the large, twiggy nests they build above ground are consumed by flames. Survivors head for the nearest source of refuge and food--often a house.

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Though a different species than the disease-spreading, garbage-grubbing Norway rat, so-called “pack rats” can nonetheless damage property and even rattle homeowners accustomed to wildlife.

Mary Ellen Strote said her bunker-like, concrete house, set on 40 pristine acres in Calabasas, has become a rat magnet--”the final nightmare” after the trauma of the Nov. 2 blaze that consumed 18,000 acres in the Santa Monica Mountains. The rats have colonized her garage and woodpile, eaten shrubs she has tried to plant, and chewed up the wires of her 1971 Mercedes-Benz. She had to have one dead rat steam-cleaned off the car’s engine.

“The mechanics told me Mercedes are good for anything--even barbecue,” Strote said.

“I would see them when I would go to get wood out of the woodpile,” Strote said of her unwelcome visitors. “I hear them. They’re nocturnal so I’ll go walk outside and I’ll feel them right next to me. I’ll hear them shuffling around. But I’ve started to avoid it. I don’t go out more than I have to ‘cause it gives me the creeps.”

The rats, in turn, have drawn stray cats--20 of them--to the Malibu home of Alan Jensen. After the brush fire that spread between western Topanga Canyon and Pepperdine University, Jensen said, “we counted as many as 37 rats the cats killed, and they were almost as big as the cats. . . . You could not walk around the property at night for fear you’d step on the rats.”

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Jensen at least knew of this aftereffect of a major fire. After one in 1985, he saw the rodents leaping from palm tree to palm tree on and near his property.

As the rats and other small mammals are displaced by the fires, they are followed by hawks, ravens and other birds of prey--producing unusually large numbers of them in the Santa Monicas these days, naturalists say.

What looks like wasteland becomes a great feeding ground for the hawks. With the chaparral burned off, they have a bird’s-eye view--literally--of what’s to eat on the ground.

The same phenomenon has been seen in the San Gabriel Mountains, where the October fires seared 5,700 acres around Pasadena, Altadena and Sierra Madre. An unusual variety of hawks--Cooper’s, sharp-shinned, red-tailed and red-shouldered--have been circling the San Gabriels’ burnt, south-facing slopes.

Not long after the fires, a western meadowlark was spotted over the Eaton Canyon Nature Center, the first reported sighting of that species there in 10 years.

Center Director Mickey Long said he has not a clue where the meadowlark came from, or why, because the aptly named bird prefers meadows over the rugged chaparral. But he assumes that its unexpected presence was somehow related to the fire.

A recent bird count throughout the region between the Santa Monicas and San Gabriels showed that birds were jammed much more tightly than usual into the pockets of vegetation spared by the fires. Despite the high concentrations, the number of species was lower, indicating that not all local birds survived, said John Fisher, who supervised the annual count for the Pasadena Audubon Society in the San Gabriels.

Two mountain lion sightings in San Gabriel Valley suburbs also have given rise to speculation that the brush fires drove the highly mobile but extremely shy cats from their usual habitats. Both back-yard sightings occurred Jan. 8, eight miles apart in Altadena and La Crescenta.

“We get occasional sightings but nothing like this,” said Los Angeles County Sheriff’s Lt. Mike Wenrich of the Altadena substation.

Much more common--and not unexpected--have been the displaced coyote and deer discovered in the suburbs abutting the fire areas.

While some creatures migrate, others adapt. Lee Kats, a Pepperdine University biologist who studies amphibians in the Santa Monicas, uncovered one of the most striking examples inland from Malibu.

Hiking into Cold Creek Canyon soon after the fire, he spotted California tree frogs that were black rather than their customary pale beige or gray. As he watched them more closely he realized that the frogs were not covered with soot but had changed color, closely matching the charred ground.

“I’ve never seen one that dark in four years,” Kats said.

For Kats, the color change is a reminder that fire is a naturally occurring phenomenon in the Santa Monicas. It shows that at least one native, the tree frog, has been equipped with “the genetic makeup to deal with post-fire conditions,” he said.

“It means . . . this frog, this species, has evolved in a habitat that semi-regularly burns.”

Experts are anticipating more such drama in the fire zones’ ever-changing ecological theater. As different plants begin to revive, they will attract a succession of hungry insects, which, in turn, provide food for birds and other wildlife.

“We’re going to see an absolute turnover in the diversity and abundance of different species,” said biologist Dennis Murphy, director of the Center for Conservation at Stanford University.

Just after the October fires in Laguna Beach, Murphy said, the hills were covered in bright, almost phosphorescent mountain bluebirds, a thrilling sight against the stark, lunar landscape left by the flames. The bluebirds, unusual in that habitat, were drawn by the army of insects displaced as the Laguna fire consumed 16,680 acres.

This spring, Murphy predicts, visitors will see a disproportionate number of a small green butterfly called the bramble hairstreak. Its favorite food, a type of lotus, grows abundantly after fire in the ash-enriched soil, and thrives also because it has less competition from other plants.

It is just one example of how the regeneration works.

New plants tend to be particularly tender and nutritious after brush fires, providing the perfect forage for starved animals, said Suzanne Goode, an ecologist for the state parks system. Invigorated by the enriched vegetation, the native wood rats, in turn, will probably have larger litters and thus replenish their ranks, she said.

That is not to say that the fires did not kill many animals or that they will not hasten the demise of threatened creatures such as the California gnatcatcher and cactus wren, two songbirds whose habitat in Orange County’s coastal sage scrub, a victim of continuing suburban development, shrank another 10% during the Laguna fire.

“For every species able to flee and now trying to adapt, there were many other species totally lost in those areas, like brush rabbits, lizards and snakes,” Murphy said.

But the quirky behavior that has alternately delighted and startled animal watchers in recent weeks could provide important leads in more methodical studies of how the post-fire environment recovers.

The National Park Service’s Santa Monica Mountains headquarters is trying to coordinate a number of proposed studies, staff ecologist Ray Sauvajot said, including one led by an Occidental College biologist that will compare the recovery of reseeded hillsides with those left to nature’s devices. The impact of animals on plant regeneration will be included, said Prof. Jon Keeley.

Murphy, of Stanford, fears that there is not enough funding available to mine the wealth of information presented by last fall’s brush fires, a pity because fires of such magnitude occur only every 10 to 20 years.

“This opportunity,” he said, “is just something we won’t be able to take advantage of.”

Times staff writer Berkley Hudson contributed to this story.