A decade-long effort is starting to turn the tide for California’s state amphibian — the California red-legged frog (Rana draytonii). This week, the Santa Barbara Zoo, in partnership with the National Park Service, assisted in the release of a group of California red-legged frog tadpoles into a carefully selected site in the Santa Monica Mountains — marking an important step in expanding the species’ range and supporting its long-term recovery.

The California red-legged frog once thrived across much of the state but experienced dramatic population losses due to habitat degradation, invasive species, and disease. Recovery efforts have made meaningful progress in recent years, with successful translocations and in situ breeding marking important milestones for the species.

The release reflects over 10 years of sustained commitment to reestablish California red-legged frogs into the Santa Monica mountains through translocation: moving portions of egg masses into historic territories to establish breeding populations. The program now includes a supplemental headstarting program where egg masses and tadpoles are raised in managed care to improve survival before returning to the wild, to mitigate the effects of recent severe environmental threats such as wildfires and intense storm systems.

This latest effort was made possible in part by the Santa Barbara Zoo’s new conservation collaboration at California State University Channel Islands (CSUCI), which has significantly expanded the Zoo’s ability to headstart the species. The dedicated space at CSUCI provides the controlled conditions needed to safely hatch and raise early life stages—an important step in improving survival rates.

The Zoo’s animal care experts provided the tadpoles the same high-quality daily care that is given to any animal in an AZA-accredited facility, and the dedicated space at CSUCI offers additional space for the conservation need to provide safer growing conditions for the tadpoles given the increasing severity of climatic events.

On March 4, National Park Service biologists collected an egg mass from the Santa Monica Mountains and transported it to the Santa Barbara Zoo’s conservation facility at CSUCI, where Santa Barbara Zoo animal care experts carefully monitored their development and raised them through the most fragile stages. The added space and resources at the site allowed the Zoo to scale up their support of this significant program.

“The new pilot facility at CSU Channel Islands has been a gamechanger for our conservation programs,” said Dr. Estelle Sandhaus, vice president of conservation & science at the Santa Barbara Zoo. “For the first time, we were able to hatch and raise a cohort of California red-legged frog tadpoles in a dedicated conservation space, giving us much-needed capacity. Releasing these tadpoles with our partners at the National Park Service brings us one step closer to restoring a federally threatened species that had disappeared from the Santa Monica Mountains for decades.”

The Santa Monica Mountains site represents a promising new chapter. By introducing tadpoles into suitable, restored habitat, conservation teams are working to reestablish a foothold for the species in an area where it can once again play its role in the ecosystem.

“The California red-legged frog recovery project has been underway for more than a decade, and while we’ve seen encouraging success, some of our reintroduction sites were heavily impacted by the 2018 Woolsey Fire,” said Dr. Katy Delaney, a wildlife ecologist with the National Park Service and the project’s lead. “We are grateful for the support of the Santa Barbara Zoo’s new center for conservation at CSUCI and hopeful these tadpoles will mature and help establish resilient new populations of this federally threatened species in the Santa Monica Mountains. Efforts like this are critical to protecting the region’s biodiversity and demonstrate the value of long-term conservation partnerships.”

Allison Alvarado, associate professor of biology at CSU Channel Islands, said, “This work highlights the power of place-based conservation in our own backyard. Through this partnership, CSU Channel Islands students are able to connect directly with ongoing recovery efforts for the California red-legged frog in the Santa Monica Mountains, gaining hands-on experience while contributing to the long-term health of local ecosystems.”

Amphibians, like the California red-legged frog, are considered indicator species, meaning their health reflects the condition of the environment around them—particularly water quality and ecosystem stability. Their recovery offers important insight into the broader health of California’s landscapes, especially as climate pressures continue to reshape habitats statewide.

As California’s largest native amphibian, the California red-legged frog’s role as an ecological indicator means they are well positioned to serve as a potential early warning system for any possible threats to freshwater systems, safeguarding critical riparian and wetland habitat. Their return to areas in the Santa Monica Mountains after decades-long absence signifies a commitment to not only species restoration, but to the long-term stability of a treasured national recreation area.

Researchers are also observing early signs that some California red-legged frog populations may exhibit a degree of tolerance to some strains of chytrid fungus, the pathogen that causes chytridiomycosis, a disease that has impacted amphibians worldwide. While the threat remains of critical concern to amphibian population sustainability, these findings offer cautious optimism for long-term recovery for the California red-legged frog.

While challenges such as drought, wildfire, and shifting climate conditions continue to affect habitats across California, conservation efforts are focused on building resilient, self-sustaining populations that can persist in the wild over time.

The Santa Barbara Zoo’s work is part of a broader network of conservation partners across California dedicated to restoring native species and ecosystems. Together, these efforts aim to support the long-term recovery of the red-legged frog and reduce the need for ongoing human intervention.

Additional releases and monitoring efforts will continue as part of the ongoing program, with scientists tracking survival, habitat use, and long-term population trends.

The Santa Barbara Zoo remains committed to advancing conservation efforts for California’s native wildlife, working collaboratively to protect biodiversity and supporting healthier, more resilient local ecosystems.