4 | June 27, 2019 | Malibu surfside news news

Glimmers of hope remain for threatened frogs

Scientists seek to

restore species’ fireravaged


Suzanne Guldimann

Freelance Reporter

The Woolsey Fire and

the record rains that followed

the disaster have had

a devastating impact on the

native amphibians of the

Santa Monica Mountains,

especially the California

red-legged frog — a species

threatened with extinction.

The red-legged frog is

listed as a threatened species

under the Endangered

Species Act and is an International

Union for Conservation

of Nature vulnerable

species. On June 19,

the National Park Service

shared details depicting the

impact area disasters had on

the species as well as what

scientists are doing to aid

the amphibians.

The large frog has been

entirely missing from its

former range in Malibu and

the Santa Monica Mountains

since the 1970s, but a population

of the amphibians was

discovered north of the 101

Freeway in the Simi Hills in

1999. Those frogs have been

carefully monitored for two

decades, and for the past five

years have been used to reestablish

the species in four

spots south of the 101.

National Park Service

ecologist Katy Delaney

has led the red-legged frog

study for more than five

years. She told the Malibu

Surfside News that prior to

the fire, the project to reintroduce

the frogs was going

well. In March of 2017, her

team found evidence that

the relocated frogs were

breeding without human intervention

and that they had

sufficient habitat, despite

the drought. That changed

when the Woolsey Fire

struck in November 2018.

Red-legged frogs need

year-round access to deep

pools of clean water to survive

and breed. They also

need vegetation for shelter,

shade and food. Only

a few streams in the Santa

Monica Mountains meet

the criteria, and three of

the four areas being used to

reintroduce the red-legged

frog were “annihilated,”

Delaney said.

“All of the sites burned,

three really severely,” Delaney

explained. “There is

no aquatic habitat left and

not much vegetation.”

Each of the streams had

a complete population of

frogs, from tadpoles to mature

adults. After the fire

and the subsequent floods,

the pools were almost entirely

filled with sediment

and debris, and only a few

adult frogs were located.

“If there is a frog here

and there that’s great, but

there are no breeding pools

left,” Delaney stated in a

press release. “They are all

filled in with debris.”

It is not all bad news. The

fourth site did not burn.

Sediment and debris from

upstream caused temporary

impacts, but, at the end of

the rainy season, some of

the deep pools the frogs

rely on were free of debris

and still retained pre-fire


That’s good news not

only for the red-legged

frog, but for the California

newt, another fragile amphibian

species that also

depends on clean, deep

pools to breed.

The red-legged frog study team looks for survivors of the Woolsey Fire in December 2018. Three of the four streams

where the frogs have been reintroduced were destroyed in the fire, but one area was not burned and the population

source in the Simi Hills survived, despite that area burning. Photos by National Park Service

Delaney explained that

both the newts and the reglegged

frogs are long-lived

species, and there is a good

chance fire survivors of

both species will be able to

breed in the future, provided

there is enough rain to

wash out the fire sediment

and restore the pools.

“Some streams filled up

with a lot of sediment,”

Delaney said. “It will depend

on the drought, and

climate change, but in 10

years, probably, with decent

normal rainfall, the

habitat will come back.”

Delaney confirmed

that there is still hope for

the frogs. While the area

around the Simi Hills

source site for the frogs

burned, their habitat was

Please see frogs, 5

Biologist Mark Mendelsohn reacts to the March 2017 discovery of California red-legged

frog egg masses in the Santa Monica Mountains.

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