Extremely rare tree frog died in Atlanta, likely marking species' extinction

The last known member of a rare tree frog species has died.

The male Rabbs' fringe-limbed tree frog was found dead in its enclosure at the Atlanta Botanical Garden during a routine daily inspection on Monday, reports the Atlanta Journal-Constitution. Staff had nicknamed the frog "Toughie," and the animal was estimated to be at least 12 years old.

But even a frog named "Toughie" couldn't tough it out alone. The only other Rabbs' frog known in captivity died at Zoo Atlanta in 2012, and that one was also a male.

Scientists didn't even know about the Rabbs' fringe-limbed tree frog (Ecnomiohyla rabborum) until 2008, when Zoo Atlanta herpetology curator Joseph Mendelson first identified the new species.

A team of researchers from the zoo and Southern Illinois University had traveled to central Panama in 2005 to collect live animals in a race to beat a fungus that devastates amphibian populations to the region. When the team returned, Dr. Mendelson discovered the new species of frog among the new collection. He named the frog for conservationists George and Mary Rabb.

Subsequent field studies suggest the deadly chytrid fungus swept through Toughie's former home in central Panama, wiping out as much as 85 percent of all the amphibians in the region. In that area, the Rabbs' frog lived in a very small range, so it's presumed that the Rabbs' frogs are extinct in the wild, making Toughie the last of his kind.

"Science had a very short window to learn about the species in the wild before this disease struck the only known locality for the frog and the species vanished," Mary Pat Matheson, the garden’s president and CEO, told the Atlanta Journal-Constitution. 

The staff at the Garden tried to save the species, and had successfully bred the male with a female, she added. But the tadpoles did not survive.

Still, Toughie has left his mark on the world. 

This frog's image was projected onto St. Peter's Basilica, his call was played for the world to hear him, and he met race car drivers and movie directors, National Geographic reports. Toughie even has his own Wikipedia page.

"A lot of people were moved to tears when they saw him," photographer Joel Sartore told National Geographic. "When you have the very last of something it's a special deal."

Although the frog had quite the following, his own voice wasn't heard by the world until 2014. Then, Mark Mandica, the head of the Amphibian Foundation who worked with Toughie for seven years, recorded the Rabbs' fringe-limbed tree frog's call one morning.

"I heard this weird call coming out of the frog [area], and I knew it had to be him, because I knew what all the other species sounded like," he told National Geographic. "I was able to sneak in and record him on my phone."

This report contains material from the Associated Press.