The San Diego Natural History Museum (The Nat) has been studying the ecosystems of San Diego County and Baja California for over 100 years. Their goal? To ensure this corner of the continent remains healthy and enjoyable – for many species – long into the future. You could say their research is what makes conservation possible. One recent success story is the return of California red-legged frogs to San Diego County.
The California State Amphibian once ranged from northern California down into Baja California. Red-legged frogs thrived in mountainous ponds until they made it onto the menus of gold miners in the 1800s, and displaced by invasive bullfrogs in the 1900s. Other exotic species, fungal disease, drought and habitat destruction continued to eat away at their populations. By 1970, the California red-legged frog was extinct in San Diego County.
But in the Sierra San Pedro Mártir, just a few hours south of the border, these frogs were hanging on. Yet only 10 populations remained on the peninsula, all with fewer than 50 adults. In 2018, The Nat teamed up with Mexican conservation organization Fauna del Noroeste (FAUNO) to build new ponds for the frogs.
Once they had settled into their new, more resilient habitat, the time came to reintroduce them to southern California. In 2020, the team partnered with organizations and government agencies on both sides of the border to translocate freshly laid eggs from Baja to ponds in San Diego and Riverside Counties.
The first-ever translocation mission happened in March 2020. Hundreds of frog eggs stored in a cooler were helicoptered out of the mountains, driven across the border to their new homes on protected land, and released.
Spring 2022 marked the third round of translocation missions, and each year has been more successful than the last. The next milestone will come when the relocated frogs mature and begin to breed on their own. To learn more about The Nat’s research and conservation work, visit www.sdnat.org/science.
