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St. Louis Zoo marks the milestone of releasing 10,000 hellbenders back into the wild

Hellbenders are among the largest amphibians in North America, growing nearly two feet long.
Mark Wanner
/
St. Louis Zoo
More than 10,000 hellbender salamanders have been released in the wild by conservationists at the St. Louis Zoo and the Missouri Department of Conservation.

Missouri conservationists have reached an important milestone in their effort to save hellbender salamanders.

In August, the number released into the wild topped 10,000, following two decades of work to collect salamanders and restore their populations.

The salamanders, also known as “snot otters,” are an endangered species and some of the largest of their kind in North America. Missouri has two subspecies, the Ozark hellbender and the eastern hellbender. The amphibians can grow up to 24 inches long and can be found under rocks and swimming through rivers in the Ozark region.

Conservationists released the first hellbenders back into the wild in 2008.

Climate change, siltation, pollution and disease are all factors in the species’ decline, said Justin Elden, the St. Louis Zoo’s herpetology curator.

“It's possible that certain populations of hellbenders have been collected for, whether it be fishing bait or pets or who knows,” Elden said. “But all these different things over the years have caused this massive decline. And that's one of the reasons why it's so important for us to be doing this work here at the zoo.”

The zoo keeps the salamanders in captivity for up to five years at the Karen Goellner Center for Hellbender Conservation, a wild care institute led by Elden.

Some scientists estimate that there were about 45,000 hellbenders in Missouri 40 years ago. A project funded by the Missouri Department of Conservation in the 1990s found that hellbenders had declined by about 77% on average. Most of the hellbenders that were found were also older.

“The real goal here is to get these animals back to their population densities that they were at 30 years ago, 40 years ago, where they were fairly common, fairly abundant,” Elden said.

Conservationists began collecting hellbenders and their eggs to breed them in captivity, said Jeff Briggler, state herpetologist for the Missouri Department of Conservation.

“It quickly led to this animal being listed as state endangered in Missouri, and then later, they got listed as federally endangered,” Briggler said. “We realized very quickly that we probably should start trying to find a way to collect eggs or breed this animal in captivity in order to save it for the future.”

Hellbenders reach their reproductive age between five and six years of age. Briggler said scientists hope at least a third of those animals make it to that age, when their probability of surviving is about 90%. Hellbenders are an important link in the food chain and an essential part of the state’s biodiversity.

Salamanders have lived in North America for 160 million years. Briggler said learning more about the amphibians helps scientists learn more about the surrounding environment.

“They breathe through their skin, so they can absorb a lot of things through their skin,” he said. “For long-lived animals, such as a hellbender, that can live 25 to 35 years, we can learn a lot about what's in the river by what's in the tissue and blood of a hellbender.”

Follow Chad on Twitter: @iamcdavis

Chad is a general assignment reporter at St. Louis Public Radio.

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