Before the wildfire came, California red-legged frogs had regained a tenuous foothold in the Santa Monica Mountains — and the small population of rare amphibians was thriving.
That was good news for the National Park Service experts who had reintroduced them to the Southern California mountains starting in 2014. The frogs had vanished from the region by the 1970s, but a population discovered in the Simi Hills north of U.S. Highway 101 gave ecologists the perfect opportunity to transplant some to the mountains, according to a news release from the Santa Monica Mountains National Recreation Area.
But the deadly Woolsey Fire “doomed” the project in 2018, park rangers said.
The fire tore through Southern California in November, threatening humans, homes and wildlife. And it “annihilated” most of the stream habitat the rare frogs relied on, said Katy Delaney, the ecologist who led the project and is now “essentially starting over,” according to the National Park Service.
“With three of the four sites, there is no aquatic habitat left and not much vegetation,” Delaney said. “I don’t even know if they are alive. They were doing great before the fire.”
Seven months later, ecologists estimate the blaze killed hundreds of frogs. The frogs are considered threatened under the Endangered Species Act.
The fire left behind burned debris and was followed by intense rain in the winter, which washed mud and silt into the streams the frogs had been living and breeding in, according to the National Park Service. That combination means that, even if some of the frogs survived the blaze, hopes for a population rebound in the near future have been dashed.
“If there is a frog here and there, that’s great but there are no breeding pools left,” Delaney said. “They are all filled in with debris.”
Luckily, the frogs from the original population in the Simi Hills managed to survive the blaze — despite the fact that it was also burned last year.
“The frogs there seem to have survived relatively unscathed,” park rangers said in the news release. “During a night survey that was done in December of that particular area, biologists found 90 frogs in the charred landscape.”
Ecologists took 1,000 eggs from that population to the Santa Barbara Zoo so they could hatch into tadpoles in safety. Those tadpoles have now been reintroduced to the wild, the news release said.
“California red-legged frogs require deep pools of year-round water, which are not easy to find in the arid climate of the Santa Monica Mountains,” park rangers said. “Many of the streams in the Santa Monica Mountains are infested with non-native species like crayfish, which can prey on frog eggs and tadpoles.”
The rare California red-legged frogs aren’t the only wildlife impacted by the blaze.
At least one mountain lion likely died in the fires, and it destroyed the habitat other mountain lions and bobcats called home, McClatchy reported last year.