1000th California red-legged frog after its release and seen underwater. (Courtesy photo)

Red-legged frogs making a comeback at Yosemite with help of SF Zoo

After four years, San Francisco Zoo officials wrapped up a successful reintroduction program Monday by releasing the last of more than 1000 red-legged frogs into Yosemite National Park.

The zoo began partnering with the National Park Service and Yosemite Conservancy in 2015 to reintroduce the threatened frogs back into Yosemite National Park, where they underwent a steady decline 50 years ago.

The park now features an all-time high of 1,073 red-legged frogs, all reared at the San Francisco Zoo.

Jessie Bushell, director of conservation at the San Francisco Zoo, said the moment felt “bittersweet.”

“We have reached our goal, but they have been part of our life for four years. This moment was in our brain for quite a while,” said Bushell.

The introduction of the non-native bullfrog, drainage of water and the proliferation of raccoons have contributed to the disappearance of the red-legged frogs in Yosemite.

“If you release 50 [bull]frogs in an area, they are massive predators and can be problematic,” said Bushell.

However, the red-legged frog quickly adapted to the environment after Yosemite got rid of the bullfrogs, an effort that took 10 years.

After two years in the wild, the Zoo-reared frogs have survived and reproduced, and some have doubled in size, according to data collected by the zoo.

“If they are given the chance, they can thrive,” said Bushell.

Yosemite National Park biologists perform regular night surveys and skin swabs to track potential disease and follow health conditions, while the zoo placed transmitters on 45 of them.

The 999th red-legged frog was the last to get tagged with a transmitter.

“The challenge is to see if they will still do well in the next five years,” said Bushell.

20 red-legged frogs are currently on display for educational purposes in the California Conservation Corridor exhibit at the zoo.


Just Posted

SF supervisor candidates back car-free streets

District 5 hopeful Preston pitches network of bike-only roads to prevent traffic deaths

Climate strike organizers say SFUSD blocked student participation

The organizers behind Friday’s Climate Strike in San Francisco are accusing the… Continue reading

City puts closure of long-term mental health beds on hold

In response to public outrage over a proposal to suspend 41 permanent… Continue reading

Here we go again – new dog rules in Golden Gate National Recreation Area

The GGNRA released a 2019 Superintendent’s Compendium that makes significant changes that appear to implement parts of the ill-fated Dog Management Plan.

Most Read