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Researcher Helps to Find Extinct Frog


Rana fisheri
Drawing by Aleta Karstad-Schueler

A genetic analysis undertaken by a Fordham professor has uncovered proof that the only species of North American frog long thought to be extinct is alive—and living 250 miles from Las Vegas.

Evon Hekkala, Ph.D., assistant professor of biology, teamed up with researchers from the Las Vegas Springs Preserve, University of Nevada-Las Vegas, University of Arizona and Tulane University to sequence 100-year-old museum samples of DNA taken from the “extinct” Vegas Valley Leopard Frog (Rana fisheri).

Initially, Hekkala said, the team set out to discover whether the extinct Leopard frog was related to today’s Relict Leopard Frog (Rana onca), which lives along the Colorado River and is a candidate for the endangered species list. The sequencing, however, showed the two frogs were not related despite their physical similarities.

Hekkala then compared the Vegas Valley Frog’s DNA to Genbank, a database that includes DNA sequencing for 62 other species of North American frogs. There, she found that the Vegas Valley Leopard Frog, which was last reported seen in the summer of 1942, was virtually genetically identical to the existing Chiricahua Leopard Frog (Rana chiricahuensis). That species’ habitat is located some 250 miles from the Vegas Valley, near the Mogollon Rim in central Arizona.

“What it means is that the only North American frog species listed as extinct is not extinct at all,” said Hekkala, lead author on the study. “For conservationists, this opens up a second chance to protect and proliferate the species.”

Hekkala was able to do the DNA sequencing using samples extracted from Vegas Valley Leopard Frogs collected in Las Vegas in 1913 and housed for a century at the California Academy of Sciences in San Francisco.

The study, “Resurrecting an Extinct Species: Archival DNA, Taxonomy, and Conservation of the Vegas Valley Leopard Frog,” was initiated by Raymond Saumure, Ph.D., a biologist at Springs Preserve, and has been published in Conservation Genetics.


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