The Relict Leopard Frog was once found in wetlands throughout northwest Arizona, southeast Nevada and southwest Utah. It was thought extinct until isolated populations were found in Nevada in 1991. Since then, searches for suitable habitats for Relict Leopard Frog reintroduction have been underway.
The Arizona Game and Fish Department identified Pakoon Springs, a small oasis in the northwest corner of Arizona, as suitable habitat, but for one major drawback… It was full of bullfrogs! Native to the eastern U.S., bullfrogs are invasive and highly detrimental in wetlands throughout the west. Voracious predators, bullfrogs prey heavily upon leopard frogs, and they also spread a fungal disease that is deadly for leopard frogs and other amphibians.
Bullfrog removal at Pakoon Springs, by multiple parties including the University of Arizona and the University of Nevada-Las Vegas, began in 2010 and was completed in 2019, when the last bullfrogs were removed. After repeated surveys confirmed the bullfrogs were gone, Relict Leopard Frogs, raised in a captive breeding program at the University of Nevada-Las Vegas, were finally released at Pakoon Springs in 2022. Follow-up surveys confirm that a self-sustaining population now thrives at Pakoon Springs.
University of Arizona researchers are conducting a similar species recovery effort for the threatened Chiricahua Leopard Frog in southern Arizona wetlands.
Amphibian species are in serious decline, world-wide. The success of these leopard frog recovery programs provides hope for other species in peril.
This Earth Note was written by Steve Schwartz and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
