Farming Frogs Can Save Them From Extinction

Diseases are killing off many of Panama’s frog and salamander species. Are there enough animals left to breed them in captivity?
Panama's critically endangered lemur leaf frog. (Photo: Matt McClain/'The Washington Post' via Getty Images)
Jan 7, 2016· 2 MIN READ
John R. Platt covers the environment, wildlife, and technology and for TakePart, Scientific American, Audubon, and other publications.

Panama’s frogs and other amphibians are in crisis.

The Central American nation—which is home to hundreds of frogs found nowhere else on Earth—has lost several species to extinction over the past 20 years. The cause is a deadly pathogen called the chytrid fungus, which infects amphibians’ skin and destroys their ability to breathe.

The fungus has been blamed for more than 100 extinctions worldwide and has been observed on hundreds of additional species.

Can future extinctions be prevented? A paper published this week in the journal Animal Conservation examines Panama’s 214 known frog species and comes up with a complex answer.

The paper, by a team of researchers from around the globe, concludes that targeted captive-breeding efforts will help to save a good number of these frog species from extinction.

It also concludes that a few of the 13 species in captive-breeding programs don’t need that help and can be left to survive on their own.

Perhaps most troubling, the study finds that eight Panamanian frog species are likely already extinct, while dozens more may be too rare to benefit from such programs because there are just too few left alive to collect and breed.

RELATED: A Rare Chance to Save an Entire Nation’s Frogs From Extinction

“This paper was very difficult to write because it involved so many people, but I think it was worth it in that it was time we actually did a clear-eyed view of what we’ve got and where we’re going,” said Brian Gratwicke, lead author of the paper and the international coordinator of the Panama Amphibian Rescue and Conservation Project.

Gratwicke said that some of the previous decisions about which frogs to breed in captivity were based on the species’ apparent uniqueness or even their popularity with certain herpetologists. The new paper develops a more rigid, systematic approach and looks at each species based on three criteria: whether a “founding population” of 20 males and 20 females could be located; whether the species could be successfully bred in captivity (not always easy); and whether a species would go extinct without help.

“If you ignore those three things, you’re doing yourself and the species a disservice,” Gratwicke said.

Using that approach, the paper came up with a list of 14 species that the authors concluded should be considered priorities for captive breeding. They include the Darien stubfoot toad, the horned marsupial frog, and the banded horned tree frog.

Not making the list were species like the La Loma tree frog, which researchers have never been able to successfully breed because life in captivity stresses it out too much.

Breeding frogs in captivity requires determining the adult frogs’ and tadpoles’ ecological needs, including food, water flow, lighting, and temperature. Learning those requirements will be critical to many species’ survival. “We need to learn to be effective frog farmers and do it sustainably,” Gratwicke said.

In addition to prioritizing species for conservation, the new paper may have another long-lasting effect. By compiling all of the known information about Panama’s frogs, it helped to identify the knowledge gaps for these species as well as the dozens of species that researchers have not been able to observe in the wild for many years. “There’s nothing like a blank in the data to get someone out into the field looking for a missing species,” Gratwicke said.