The wildlife reintroduction project has been a struggle. 104 mountain yellow legged tadpoles from Southern California have died at the zoo over the last several months.
The Chaffee Zoo's large collection of colorful, exotic frogs coupled with its reputation of having a successful frog breeding program made it the natural choice to help save an endangered species.
After the destructive 2009 Station Fire in Southern California, 106 tadpoles were rescued from a stream in the San Gabriel Mountains. They were taken to Fresno's Chaffee Zoo in hopes they would grow into adult /*mountain yellow legged frogs*/. But after about a year the tadpoles began to die.
Scott Barton, Chaffee Zoo Director said, "There's something going on that we're unaware of and they're showing the symptoms when they metamorphose between the tadpole stage and the adult stage."
Barton says no pesticide residue was found in the tadpoles.
"We know it's not the chytrid fungus. We know it's not the common things we would find," said Barton. "In fact what it looks like is a calcium deficiency."
The /*San Diego Zoo*/ has been able to successfully breed the mountain yellow legged frog. It even released tadpoles back into the wild in hopes of increasing the frogs' population.
Jeff Lemm, Research Coordinator said, "This is a critically endangered species. There's maybe 200 left in the wild."
The Chaffee Zoo was unable to duplicate San Diego's success. The two remaining mountain yellow legged frogs in Fresno are being kept in a quarantined area but they appear to have the same metabolic issues.
Barton said, "We are seeing some of the same symptoms we've seen the past frogs so realistically we are not optimistic about these."
Scott Barton calls it a very humbling experience.
The zoo has had a great deal of success with frogs but the massive deaths of these tadpoles have been a real mystery.