First Zoo-Raised Hellbender Reproduces in the Wild

The Missouri Department of Conservation (MDC) have announced that for the first time they have recorded a zoo-raised ozark hellbender reproducing in the wild. Conservationists from MDC were able to confirm the milestone during a survey of nesting hellbenders in October 2022.

This male discovered by biologists from MDC was released in 2019. It was first seen attending a nest of 128 eggs and on a follow up visit was observed protecting the eggs as they began to hatch.

“We are very excited to announce this news,” said Missouri State Herpetologist Jeff Briggler. “This is the first documented event of a zoo-raised animal fathering a clutch of eggs in the wild.”

Ozark hellbenders once numbered as much as 27,000 in the wilds of Missouri but this has dropped to just 1,000 leading to them being listed on the federal endangered species list. MDC formed a partnership with the Ron and Karen Goellner Center for Hellbender Conservation, a part of the Saint Louis Zoo WildCare Institute in the early 2000s to try and reverse this decline.

A key strategy of their turnaround was head starting. This involves collecting eggs from wild hellbenders and raising them at the Saint Louis Zoo for between 3 and 8 years. These hellbenders which are then larger in size and more able to defend themselves are released to the wild. The program started in 2008 with numbers growing to 1,000 per year by 2012.

Over 10,000 ozark and eastern hellbenders have been returned to the wild as a result of this program helping to bolster populations of the threatened species.

Another part of the recovery effort is regular monitoring by biologists from the MDC. The work to monitor the population and locate nests which may be suitable candidates for the head-start program.

“The majority of the hellbenders existing in the wild and all 10,000-plus released animals have a small chip embedded under their skin with a unique number to allow us to identify the animals in future encounters,” Briggler explained.

Despite releases beginning in 2008 most of the individuals are only just now reaching sexual maturity and reaching a point where they can breed. Few nests are found each year and this makes it hard to capture a male attending to his nest.

“We’re lucky to find 20 nests in the wild a year and finding a tagged father that was raised at the Saint Louis Zoo was like finding a needle in a haystack,” said Briggler. “We have been patiently waiting for this significant achievement to occur.”

“Our ultimate goal was to see the successful reproduction of a zoo-reared animal in the wild,” explained Briggler. “And we’ve now accomplished that goal in our journey to save the unique Ozark salamander.”

Saint Louis Zoo have a dedicated team with 20 years of experience in raising hellbenders. “We have a dedicated team of hellbender keepers, life-support systems technicians, and veterinary staff who work tirelessly to make sure these animals get the best care possible at the Saint Louis Zoo,” explained Justin Elden, Curator of Herpetology and Aquatics at the Saint Louis Zoo, and Director of the Saint Louis Zoo WildCare Institute Ron and Karen Goellner Center for Hellbender Conservation.

In addition to the Saint Louis Zoo, MDC partnered with the National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, and the Arkansas Game and Fish Commission to enhance propagation efforts to ensure hellbenders remain a part of Missouri’s biodiversity.