California frog comeback

Humans and AI assist an amphibious relocation

By Nathan Rott | NPR

Published July 28, 2025 5:00 AM

The California red-legged frog, the largest native frog west of the Rocky Mountains, is listed as threatened under the Endangered Species Act.

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Bradford Hollingsworth

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The San Diego Natural History Museum

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Topline:

California red-legged frogs — amphibians that had been eaten, bulldozed and eventually pushed out of the state decades earlier — are croaking, more like groaning, in Southern California again after a monumental effort to bring them back to their historic range.

The good times: The California red-legged frog is the largest native frog species west of the Rocky Mountains. It used to be found in ponds and waterways from northern Baja California to above the San Francisco Bay, with populations as far inland as the Sierra Nevada. The frog's prevalence made it a popular food source in the 1800s and for miners during the California Gold Rush — and it was the subject of a famous Mark Twain work.

What went wrong? Wetlands were drained for agriculture and homes. Streams were dammed. Diseases struck. And the American bullfrog, a fearsome predator and the largest native frog east of the Rocky Mountains, was introduced. In 1996, the California red-legged frog was listed as threatened under the Endangered Species Act. "It's now occupying less than 70% of its historic range," says Susan North, director of stewardship for the Nature Conservancy in California.

Why reintroduce them to SoCal? The goal of a translocation, or assisted migration, is to either move a species back to a place it's been extirpated from, or to a more suitable habitat. The latter is becoming more relevant as the climate warms and ecosystems change.

Read on ... to see pictures of the frogs and learn how scientists used AI to know if their relocation efforts were working.

It had been five years since the first of the frog eggs had been moved, carefully plucked from Mexico's Baja Peninsula and transported by cooler to Southern California. Anny Peralta-Garcia was getting nervous.

The eggs belonged to California red-legged frogs, an amphibian that had been eaten, bulldozed and eventually pushed out of the state decades earlier. Peralta-Garcia, an Ensenada-based conservation biologist, had helped harvest fresh eggs from a pond in Baja. The efforts to move them back to the frogs' historic range in California had been monumental — involving private landowners, federal agencies, conservation groups, helicopters and an international border.

And now, 87 more moved egg masses later, everyone was waiting to see if it worked. If the re-introduced frogs were breeding.

"We were like, OK, if frogs reach sexual maturity in two years, maybe three, maybe four, we should be seeing something," Peralta-Garcia says. "But then, third year, fourth year, nothing."

California red-legged frog eggs seen from underwater.

Finally this year, the scientists tried something new to listen in on the frogs: artificial intelligence. A customized AI model sifted through thousands of hours of audio recordings from the relocation sites and picked out the sound of mature male frogs calling — grunting, more like — at their new location.

It was the first time the California red-legged frog had been heard in the wilds of San Diego County in 25 years, and a new egg mass soon followed.

It's the latest example of how new technologies like AI are helping muddy-boot biologists and wildlife conservationists fight an ever-worsening extinction crisis.

"It's been like an impossible dream since the '90s to actually be able to go out and see wild frogs at these sites again," says Robert Fisher, a biologist with the U.S. Geological Survey.
Here's how it happened.

The celebrated jumping frog of Calaveras County

At about five inches, the California red-legged frog is the largest native frog species west of the Rocky Mountains. It used to be found in ponds and waterways, from northern Baja California to above the San Francisco Bay, with populations as far inland as the Sierra Nevada.

The frog's prevalence made it a popular food source in the 1800s and for miners during the California Gold Rush, says Bennett Hardy, an amphibian ecologist at the San Diego Natural History Museum. "It was kind of the hot cuisine at the time," he says.

The frog leaped to national fame with Mark Twain's short story The Celebrated Jumping Frog of Calaveras County, which helped launch his writing career.

A frog's face is seen just breaking the surface of water with lots of red plant material on it.

But the next 150-or-so years weren't so great. Wetlands were drained for agriculture and homes. Streams were dammed, diseases struck and the American bullfrog, a fearsome predator and the largest native frog east of the Rocky Mountains, was introduced.

In 1996, the California red-legged frog was listed as threatened under the Endangered Species Act.

"It's now occupying less than 70% of its historic range," says Susan North, director of stewardship for the Nature Conservancy in California. That includes a stretch from Los Angeles to northern Baja California with zero populations.

"So that's a 260-mile gap in the range of the species," she says. "With a gap that size, you're not going to have five-inch frogs re-colonizing their range naturally."

A group that includes the Nature Conservancy was formed in the mid-2000s, and the decision was made to help bring them back. Genetic testing showed the frogs that used to live in Southern California most closely resembled remnant populations in Mexico.

"So in thinking about reintroducing frogs and bringing them back and restoring these ecosystems, it became clear we needed a Mexican source for the frogs," Fisher says.

An overhead image shows people with a cooler walking in a wilderness landscape.

In Mexico, Peralta-Garcia and her nonprofit Fauna del Noroeste set to work preserving the Baja Peninsula's last-remaining populations of red-legged frogs, restoring habitat and boosting their populations with the support of the U.S.-based groups.

Meanwhile, in Southern California, two sites with multiple water bodies were identified as suitable habitats in San Diego and Riverside counties. They were cleared of invasive, predatory bullfrogs.

In 2020, after a tangle of paperwork and permits, the first translocation took place.

"It was like planes, trains and automobiles," Fisher says. "It was just a lot of different moving parts."

An egg mass was moved by helicopter and car, down dirt roads and over the U.S. border to one of the prepared sites in Southern California. Others followed. The wait began.

Tasking AI to listen for frogs

The goal of a translocation, or assisted migration, is to either move a species back to a place it's been extirpated from, or to a more suitable habitat. The latter is becoming more relevant as the climate warms and ecosystems change.

For a relocation to be successful, the moved species needs to be able to survive on its own in its new environment. It needs to be self-sustaining. And to self-sustain, the frogs needed to be breeding.

The easiest way to know if frogs are breeding is by listening for their calls, says Hardy. "When frogs are calling, most of the time, that's the male of the species using those calls as an advertisement."

But trying to listen out for occasional nocturnal mating calls is tedious work. "I'd love to be out there every night at these ponds, with my tent and camping and trying to listen for them, but it's just not feasible," he says.

So instead Hardy and the team set up a series of microphones around the relocation sites.

The microphones recorded audio from dusk to dawn, day after day, week after week, collecting thousands of hours of audio during the frog's winter mating season.

But that led to a new problem. Hardy says they'd need an army of ears "to be able to sort through all these files and find where the frogs are."

To help reduce the time and effort, the team partnered with outside engineers to create a custom machine learning model — similar to the popular birding app Merlin — trained to sort through the data and detect the calls of two species: the California red-legged frog and their competitor, the non-native American Bullfrog.

A pond with brown and green foliage. Tree branches, white clouds and the blue sky reflect off the surface of the pond.

It wasn't perfect at first. Hardy says that early on, the model flagged a call that it thought was a frog but was in fact a hooded merganser, a bird that's also known as the frog duck because its mating calls sound so similar to a frog's. But with time, they've been able to refine the model and are now working on a real-time alert system that will let biologists know instantaneously when a Bullfrog or red-legged frog is detected.

For Clark Winchell, a long-time muddy-boot biologist with the U.S. Fish and Wildlife Service, the technology has been revelatory.

"I spent countless hours by myself in a kayak listening for bullfrogs. It's not the most efficient use of time," he says. "What they've done with AI on this project is incredible. It's systematic monitoring of two species."

Using the model, earlier this winter, they were able to identify the grunts of a California red-legged frog. Soon after, a survey found a new gelatinous ball of fresh eggs near the microphone that recorded it.

North, who'd helped spearhead the effort for more than a decade, says it brought tears to her eyes. There's still work to do, she says. There's still a lot of gaps in the species' historic range.

But in some parts of Southern California, for the first time in decades, she says, "We're hearing them again."

Criminal Justice

OC judge resigns

He also pleaded guilty to mail fraud

Jill Replogle covers public corruption, debates over our voting system, culture war battles — and more.

Published January 12, 2026 4:46 PM

A view of a tall building from closeup and below.

Orange County Superior Court in Santa Ana.

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Jill Replogle

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LAist

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Topline:

An Orange County judge pleaded guilty on Monday to one count of mail fraud for his role in a scheme to defraud California’s workers compensation fund.

Who’s the judge? Israel Claustro was a long-time prosecutor who won election to Orange County Superior Court in 2022.

What did he do? While working as an O.C. prosecutor, Claustro also owned a company that billed the state for medical evaluations of injured workers. That was illegal because, in California, you have to be licensed to practice medicine to own a medical corporation.

Anyone else involved? Claustro’s partner in the business was a doctor who had previously been suspended for healthcare fraud and therefore was prohibited from being involved in workers’ comp claims. Claustro knew this and paid him anyway, according to court filings from the U.S. Attorney’s Office.

Will he go to prison? Claustro could be sentenced to up to 20 years in prison, but the U.S. Attorney’s Office is recommending probation instead as part of the deal. In an email to LAist last week, Claustro’s lawyer, Paul Meyer, said his client “deeply regrets” his participation in the business venture and was resigning as judge “in good faith, with sadness.”

What’s next: Claustro is scheduled to be sentenced on June 26. California’s Constitution calls for the governor to appoint someone to temporarily replace Claustro on the bench for the next few years, followed by an election.

Go deeper … on the latest in Orange County.

Who gets to be a parent is being reshaped by increased access to IVF

The nation's first IVF baby was born in 1981, when the process was such a novelty that she was referred to as a "test tube baby." Since then, its use has surged in the United States, and today, IVF accounts for almost 100,000 births each year. That's up 50% from 10 years ago.

With IVF, which accounts for around 2% of births in America, a woman's eggs are retrieved from her body and fertilized with sperm in a lab. The resulting embryo is then implanted in her uterus, with the hope it will lead to a pregnancy.

This process has opened the door for many people who couldn't otherwise conceive children and reshaped who gets to be a parent, including more LGBTQ+ couples.

It has also become a big driver in the number of older single mothers in the U.S. at a time when the country's overall birth rate is declining. The number of unmarried women in their 40s who are having babies has grown by 250% in the last 30 years, according to data from the government. A portion of these women have partners, but many don't.

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There are many reasons for this rise, says Rosanna Hertz, author of the book Single By Chance, Mothers by Choice. Increasingly, she says, young women are pursuing higher education, focusing on their careers, or fulfilling personal goals such as traveling around the world or buying homes.

And when they're ready to partner up in their mid-30s, "there's no one to settle down with," says Hertz, a sociologist with a focus on gender and family at Wellesley College. "So, am I going to spend my time waiting for somebody to come along?"

Hertz says her research shows most women who want a family would rather do it with a partner. For them, IVF is Plan B. But as their reproductive windows narrow with age, some decide to move forward by themselves.

A framed photograph of two women, both with light skin tone wearing light-colored clothes in front of a white background, pose for a photo where one woman is holding a baby wrapped in a pink blanket. The frame sits on a wooden shelf in front of a brick wall.

Becoming a mother is a marker of adulthood for them, Hertz says.

"There is a sense that I'm now ready to do something that is selfless, that involves the care and nurture of another human being and be part of a broader community," she says. "What a child does is tie you into a community."

Do I really want to have a baby? How do I choose a donor?

Terry saw that care and community in her own sister's family, when it drew her to Nashville to spend time with her nephews.

Once she knew she wanted to be a mom, she started mapping out her path through the language she understood, which is spreadsheets and PowerPoints.

"I made a decision tree," she says.

The root of that tree was a fundamental question: Did she really want a child? It branched from there to examine how she would become a mother and which path would give her the best chance of having a baby. It led her to IVF.

Soon enough, she was faced with another decision: choosing a sperm donor. Faced with an array of choices, she resorted to another spreadsheet "that was like 30 rows long and 30 columns wide."

In it, she started by listing factors like race, height, ethnicity and education. Then she narrowed it down to a few that really mattered to her: "I cared about some physical attributes to look like me. And I cared about family health history."

Terry was extremely lucky with her IVF process: She got pregnant on her first try. She gave birth to Eleanor in 2021 and Margaret came two years later.

"I should be quite grateful for what my process was," Terry says. "The results were beyond what you statistically expect."

A woman with light skin tone, wearing a black shirt with floral print, eats a slice of cucumber facing two children sitting and standing on chairs with peeled and cut cucumbers on cutting boards on a counter.

She's right: The odds of conceiving a child with just one try of IVF are below 50% after a woman turns 35. And the chances drop rapidly each year after that. Many women try multiple cycles of IVF with no guarantee that they'll get pregnant.

Pregnancies at an older age can also carry health risks for both mom and child, with a high chance of miscarriage. All of this can take a huge physical and emotional toll.

Women with higher education are the top users of IVF

When Kate Snyder, who lives in northern New Jersey, was ready to have a kid, she looked for the right guy. "And, you know," she says, "it didn't happen."

Snyder was already in her 40s when she started thinking of IVF.

A woman with light skin tone, wearing a denim shirt, walks down a set of wooden stairs in a home while holding the hand of a small child.

"Once I came to terms with the fact that the father of my child doesn't have to be the person I end up with, and you separate the two, it's very freeing," she says. "And it just took the pressure off."

Now 48, she is the mother of a 2-year-old daughter, who loves to talk and fills their home with chatter. "She comes home from day care with gossip," says Snyder, who is an interior designer and artist. "She's telling me who pooped their pants and how the teacher had a lollipop today and this person got out of her cot."

Snyder says Google, her former employer, covered a small portion of the cost of freezing her eggs. But she paid for the IVF process herself.

Each time a woman tries to get pregnant via IVF, the cost can range from $15,000 to over $30,000. It's why IVF is out of reach for many.

A woman with light skin tone, light brown hair, smiles as she looks at a small child in a car seat.

It's gotten the attention of President Trump. In October, he announced proposals to help reduce the cost of the drugs necessary for IVF. He also encouraged employers to offer broader infertility coverage directly to workers.

Some people go into debt, while others like Snyder use up their savings. Some women, like Terry, have theirs covered by insurance. Even that is not common — only 1 in 4 companies with more than 200 employees pays for a part of the process.

Women with higher education — especially master's degrees, doctorates or professional degrees — are more likely to use IVF than those with less education, according to the U.S. Department of Health and Human Services.

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These women, on average, have higher incomes. All that gives them the agency to start and support their own family.

"My knees hurt"

Both Terry and Snyder were financially comfortable enough to step off the career treadmill and create time and space for their new families. Snyder now works four days a week. Terry took a pay cut for a different role that was less intense — it allowed her to work from home and requires less travel. Neither has qualms about it.

A woman with light skin tone, wearing a denim shirt and jeans, sits on a floor with toys and books around her.

Still, parenting in your 40s is hard.

"It's so physical being a mom. I don't think I expected that," says Snyder, thinking back to her first two years of motherhood and carrying her daughter up and down the stairs or getting her in and out the car. "Motherhood in your 40s, you know, my knees hurt and there are things that are starting to fall apart."

For Terry, one of the hardest parts of being a single mom is not being able to take a break. "If I'm tired or had a rough day at work or I'm frustrated, I'm feeling overwhelmed and I want to step away from my kids, I often can't," she says. "I have to meet their needs first and meet my needs later. And that's hard."

And then there is the weight of decision-making. She discusses her choices with her friends and family, "but ultimately all of that rests on me and that feels really heavy," she says.

A woman and two young children with light skin tone sit on a carpet with an alphabet design.

"Was he sorry I didn't have a husband?"

Even though there are more families like Terry's and Snyder's today, they're still rare. And society hasn't quite caught up with them.

Like when Terry moved to her new home in Nashville, she introduced herself and the girls to a neighbor, who asked what her husband did for work. Terry explained that they were a "mom and kids family" with two cats. The response took her aback.

"He said, 'Oh, I'm so sorry,'" she recalls. "Was he sorry I didn't have a husband? I still don't know to this day. But there is very much like a moment of feeling other and different — and that's often an uncomfortable feeling."

Terry worries about how her daughters will handle such questions. She prepares her oldest child by role-playing with her. But even then, sometimes it doesn't quite play out the way they've practiced.

Recently, she recalls, one of her daughter's classmates said, "'Hey, Eleanor, is that your mom?' And she said, 'Yes.' And they said, 'Well, where's your dad?' And Eleanor just froze in that moment."

But more often than not, the tenderness of motherhood triumphs over such unsettling interactions. Terry treasures the sweet moments she shares with her kids, like when they climb onto her bed in the morning to wake her or when they sit next to each other on the couch to read before bedtime.

"I love moments where they say, 'Mama, I need a snuggle.' Just holding them for a minute or two and seeing how that calms them is really, really powerful."
Copyright 2026 NPR

A woman with light skin tone, wearing a cream-colored sweater, reads a book to two small children sitting at her sides on a couch.

Housing & Homelessness

Eviction lawyer charges

LA eviction attorney faces state bar discipline

David Wagner covers housing in Southern California, a place where the lack of affordable housing contributes to homelessness.

Published January 12, 2026 1:16 PM

Two men with light-tone skin appear in side-by-side windows. Each wears a dark suit and red tie. The chyron at the bottom reads: Q&A session and has contact info for the eviction attorney.

Dennis Block discusses Southern California tenant protections in a video posted by the Apartment Owners Association of California.

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Screenshot via YouTube

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Topline:

Over his nearly 50-year career, Burbank-based attorney Dennis Block has built a reputation as a staunch advocate for Southern California landlords seeking to evict their tenants. But disciplinary charges filed against him last month by the California State Bar raise questions about his treatment of clients.

The allegations: Block faces charges involving a series of clients over a span of years. According to the 10 counts against him, Block allegedly collected fees wrongly described as “non-refundable,” failed to account for his charges and didn’t return a client’s property in a timely manner following termination of his employment. In one case, Block allegedly failed to pay court sanctions on time. In another, he allegedly created a conflict of interest by representing both a tenant and her landlord.

The backstory: This isn’t the first time Block has faced repercussions for alleged ethical lapses in recent years. In 2023, LAist reported on a filing Block’s firm submitted in an eviction case that contained multiple references to fake case law. Legal experts told us the filing, which led to court sanctions, was likely produced through misuse of AI.

Read on… to learn why legal ethics experts say the charges are serious.

Over his nearly 50-year career, Burbank-based attorney Dennis Block has built a reputation as a fierce advocate for Southern California landlords seeking to evict their tenants.

But disciplinary charges filed against him last month by the California State Bar raise questions about his treatment of clients.

Block faces charges involving a series of clients over a span of years. According to the 10 counts against him, Block allegedly collected payments wrongly described as “non-refundable,” failed to account for his fees and didn’t return a client’s property in a timely manner following termination of his employment.

In one case, Block allegedly failed to pay court sanctions on time. In another, he allegedly created a conflict of interest by representing both a tenant and her landlord.

When LAist asked Block how he responded to the charges, he told us to reach out to his defense attorney Erin Joyce. In a statement, Joyce said, “While we cannot comment on the specifics of the case, we believe the matter will be resolved in Mr. Block’s favor prior to trial at the settlement conference.”

The ultimate penalty in California State Bar Court is disbarment, which would prevent Block from continuing to practice law. Lesser punishments could involve a brief suspension or an order to complete an ethics exam.

Should fees have been ‘non-refundable’?

This isn’t the first time Block has faced repercussions for alleged ethical lapses in recent years.

In 2023, LAist reported on a filing Block’s firm submitted in an eviction case that contained multiple references to fake case law. Legal experts told us the filing, which led to court sanctions, was likely produced through misuse of AI.

Legal ethics experts said the new charges against Block are serious.

“The worst thing a lawyer can do is steal a client's money,” said Scott Cummings, a law professor at UCLA. “This is effectively what the bar is saying Mr. Block has done here in roughly half a dozen cases.”

Many counts involve Block allegedly charging up-front fees described by his firm as “non-refundable.” Bar rules state such fees must constitute a “true retainer,” meaning money paid to reserve an attorney’s availability for a specific case or period of time.

LAist previously reported that former clients have complained about poor communication and a lack of availability from Block and his associates.

Richard Zitrin, an emeritus lecturer with UC Law San Francisco, said the rules may sound esoteric, but the bar takes violations seriously.

“When you get right down to what's going on under the surface, it looks like the accusations are that this guy could not do the work for these various clients,” Zitrin said. “If it's one time, it could just be an honest mistake. But if he's doing it repeatedly, serially, of course that's of more concern.”

Representing both sides?

In one case, Block’s firm is accused of taking on a tenant who was in a dispute with her roommate. A few months later, while still representing the tenant, Block’s firm allegedly took on the tenant’s landlord. Block’s firm then sent a letter threatening to evict his own client, according to the charges.

“Lawyers cannot represent opposite sides of a particular case because they owe their duty of loyalty and confidentiality to each client,” said Laurie Levenson, a law professor at Loyola Law School. “It's very likely that one side or the other will feel that the lawyer sold out to the other client.”

Despite the severity and the number of allegations, UCLA’s Cummings said Block’s disciplinary record — which shows no infractions so far — could help him avoid disbarment.

“Suspension seems like — if these facts were all proven to be true — definitely an appropriate sanction in this particular case,” Cummings said.

It’s not yet clear what the charges could mean for Block’s firm, which prides itself on handling a high volume of cases at any given time. Block once reportedly described himself as “a man who has evicted more tenants than any other human being on the planet Earth.”

A status conference in Block’s case is set for Feb. 9.

Hey, LA listener!

The Brief

The celebrated jumping frog of Calaveras County

Tasking AI to listen for frogs

Keep up with LAist.

Who gets to be a parent is being reshaped by increased access to IVF

Do I really want to have a baby? How do I choose a donor?

Women with higher education are the top users of IVF

"My knees hurt"

"Was he sorry I didn't have a husband?"

Should fees have been ‘non-refundable’?

Representing both sides?