Breeding Experts Puzzled by Death of 104 Endangered Frogs


More than 100 endangered mountain yellow-legged frogs have died in a captive breeding program in Fresno, California, the Los Angeles Times reports. The 104 frogs died over the past month after recently metamorphosing from the tadpole stage. Experts are still struggling to figure out what went wrong.

“We have two frogs left,” Scott Barton, director of the Fresno Chaffee Zoo, told The Times. “We’re trying to determine exactly what happened.”

It is estimated that fewer than 200 mountain yellow-legged frogs exist in the wild. Native to California’s San Bernardino, San Gabriel and San Jacinto mountains, the species’ population has been dramatically affected by loss of habitat and the introduction of nonnative species such as trout, crayfish and bullfrogs. The frogs are also vulnerable to pesticides and fungal infections.

The frogs at the Fresno Chaffee Zoo were rescued from the San Gabriel Mountains after a devastating fire in 2009. Renowned for its amphibian husbandry, Chaffee Zoo is one of three facilities currently breeding the mountain yellow-legged frog for reintroduction.

In San Diego, experts have encountered similar barriers. Seven adult frogs died at the San Diego Zoo’s Institute for Conservation Research in 2006. Last year, the Institute released 36 tadpoles; researchers have been unable to find evidence of their survival.

“These frogs are very specific in their requirements. What works for one group may not work for another,” said U.S. Geological Survey ecologist Adam Backlin. “The problem is that zoos do not have the space, staff or the funds … [the frogs need] almost constant attention.”

“We were thrown a curve ball with a species that was new to us,” said Barton.

Barton added that the Chaffee Zoo may send its remaining pair of frogs to another facility, “to see if someone else will have better luck.”

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Photo credit: USFS Region 5


Charlie Parkinson

Chytrid strikes again???

April W.
Angela Weber6 years ago

Terribly sad! People try to correct the mistakes of others only to have this happen. I hope they try again.

K s Goh
KS Goh6 years ago

Thanks for the article.

Linda James
Linda James6 years ago

While studying Biology in college, an astute professor said, frogs are like the Canary birds in the underground mines. If they suffer in that environment, we, as humans, will also soon suffer. What ill effects the frogs are under must be understood, for it will soon affect us. Anyone there also attuned? Do not let your voice be silent. Frogs, honey bees, birds, butterflys, aquatic life and others are telling us humans something. Please in some way get involved. I find that the NRDC (Natural Resources Defense Council) an easy first step in having a voice on how others, including the government, makes decisions toward the impact of our small earth. Please, do and/or say SOMETHING.

Judith Corrigan
Judith Corrigan6 years ago

Fingers crossed!

Shelby Hooyenga

Poor little guys, I hope they make a comeback! Please save them!

Lindsey Williams
Lindsey Williams6 years ago

thanks for sharing.

tracey p.
tracey p6 years ago

How sad for these lovely frogs.

Cyndi P.
Cynthia P6 years ago

Oh how tragic! Thank you for keeping us informed!

Carrie Anne Brown

sad news! but thanks for sharing :)