UCSD - University of California - San Diego

09/09/2026 | Press release | Distributed by Public on 09/09/2026 15:51

Birch Aquarium Releases 223 Endangered Frogs Back Into the Wild

Published Date

September 09, 2026

Article Content

This summer, Birch Aquarium at Scripps Institution of Oceanography at UC San Diego released 223 Mountain Yellow-legged Frogs into their native habitat in Southern California's San Jacinto Mountains. The release marks Birch Aquarium's second successful reintroduction of this endangered amphibian and another hopeful step toward recovery.

"It was incredibly exciting to be part of another successful release of Mountain Yellow-legged Frogs. After watching these frogs grow from tadpoles into healthy juveniles, there's something especially rewarding about seeing them take that final leap back into their native habitat," said Sean Bruce, Assistant Curator of Fishes and Invertebrates.

The aquarium received the frogs as tadpoles from the San Diego Zoo Wildlife Alliance (SDZWA) last summer and raised them behind the scenes until they were ready for release. To support a healthy, widespread population, the frogs were then released in two groups at different locations throughout the San Jacinto Mountains. Researchers from SDZWA and the U.S. Forest Service joined Birch Aquarium at both releases to help support the effort.

Mountain Yellow-legged Frogs are carefully released into a creek. Photo by Jordann Tomasek.

Frogs Gone Wild

The first release took place in early August, when approximately 74 frogs were released along a creek near Idyllwild, California. The site also offered encouraging signs of recovery, as researchers spotted several adult frogs that SDZWA had previously released as tadpoles. Researchers were even able to tag one of the frogs, allowing them to track its progress in the years ahead.

A few weeks later, Birch Aquarium completed its second release just a few miles down the road along another creek, releasing 149 frogs. Alongside the aquarium, SDZWA also released two additional frogs and 170 tadpoles as part of their ongoing reintroduction work.

"Spotting wild frogs at one of the release sites was especially meaningful, as it was an encouraging sign of a healthy habitat and gave me hope that our newly released frogs can thrive there, too," said Bruce.

Going forward, researchers will continue to monitor the frogs at the release sites several times a year, tracking their progress and looking for further signs of recovery.

A Mountain Yellow-legged Frog rests along the edge of a creek. Photo by Jordann Tomasek.

A Leap Forward, Together

To date, Birch Aquarium has reintroduced more than 440 Mountain Yellow-legged Frogs into the wild as part of an ongoing collaborative effort with partners across the region.

"The San Diego Zoo Wildlife Alliance has been an amazing partner, and I'm incredibly proud of the work we've done together to support this important conservation program for our region's native wildlife," said Bruce.

Alongside SDZWA, several other partners are involved in this long-running recovery program, including the U.S. Fish and Wildlife Service, U.S. Geological Survey and California Department of Fish and Wildlife. Together, these partners are working to enhance the genetic diversity of captive and wild populations, improve reintroduction efforts and increase wild frog populations.

This ongoing conservation work is also at the heart of Birch Aquarium's Imagine Wild: Mountain Yellow-legged Frog exhibition, presented by The Lodge at Torrey Pines, which highlights the collaborative efforts underway to help bring this endangered species back to the wild.

Researchers from Birch Aquarium and San Diego Zoo Wildlife Alliance release Mountain Yellow-legged Frogs into a creek. Photo by Jordann Tomasek
UCSD - University of California - San Diego published this content on September 09, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on September 09, 2026 at 21:51 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]