World-first successful wild release of endangered broad-headed snake

Studying the broad-headed snake over such a long period has allowed Professor Webb to not only better understand the reclusive reptile’s life cycle, but also to tease apart the effects of fluctuations in rainfall, and droughts and fires, on population numbers.

The species has a slow life cycle compared to other snakes, such as the fast-growing brown snake or red-bellied black snake. It can take five years for broad-headed snakes to reach adulthood, and females only reproduce every two or three years. In the wild, adults can live for up to 23 years.

This slow life cycle means even small population losses can take decades to recover. Natural disasters such as bushfires and drought, as well as habitat destruction due to the removal of bush-rocks for landscaping, has led to a dramatic decline in numbers.

“The removal of bush rocks from rock outcrops means juvenile broad-headed snakes don't have shelter or food, because they only eat other small, rock dwelling lizards such as geckos and skinks,” said Professor Webb.

“In 1999, the NSW government officially recognised bush-rock removal as a Key Threatening Process because it harmed native reptiles, plants and mammals, but the rules need to be enforced. We need a permit system that requires the people selling bush-rocks to prove that they haven’t taken rocks from areas where threatened species live.

“You can still buy rocks and boulders taken from the bush at your local landscape supplier, which is something I find really frustrating. Feature boulders can sell for $450 each. That’s a pretty strong incentive for people to remove rocks from the bush.”

Professor Webb’s monitoring revealed that the broad-headed snake population declined during the 2017–19 drought. The 2020 bushfires dealt another blow, with little breeding recorded for the following three years, contributing to a decline of around 64 per cent by 2023.

So far, eight broad-headed snakes have been bred in captivity through the Aussie Ark program, which started in October 2024. Two were retained because of their valuable genetics, with six released into habitat restoration sites in mid-May 2026.

The juveniles were released beneath specially designed artificial rocks, developed by Dr Benjamin Croak, who completed his PhD at UTS under Professor Webb’s supervision. The rocks have the right crevice size and mimic the thermal properties of natural rocks.

“The artificial rocks have been critical to the survival of the juvenile snakes. Broad-headed snakes are nocturnal so they shelter under these rocks during the day and rely on them for warmth, protection and to attract prey,” said Professor Webb.

The reintroduction program also includes training and support for Indigenous rangers to help monitor and protect the species On Country. Professor Webb and the team have conducted fortnightly surveys to monitor survivorship.

When the snakes were first released, Indigenous Ranger Ashley Thomas said the project meant far more than conservation alone.

“I love it, it’s not a job for me, it’s a passion of mine. It’s about all of us coming together to do what’s best for Country. Healing Country,” Mr Thomas said.

Traditional Owner Frank Connolly Jr. said the program is helping connect younger generations with culture and Country.

“The broad-headed snake is important to our culture. It’s great for our young people growing up to learn all of this, to keep it going for the next generation coming through,” Uncle Frank said.

Aussie Ark Founder Tim Faulkner said the release of the juvenile snakes into the wild was a proud and emotional moment for everyone involved.

“We have worked for many years, navigating so much red tape, to get to this moment. We now have a unique, multi-faceted, holistic program that’s a model for threatened species conservation Australia-wide, and I couldn’t be prouder of our team and our partners,” Mr Faulkner said.

Professor Webb said the focus over the next few years would be on restoring habitat and releasing more captive-bred snakes at selected sites, building on the success of the initial trial.

“It’s exciting to go out there and see how the snakes are doing. I feel like a kid again. Hopefully, we’ll see these populations stop declining and start increasing again.”

If you would like to support Aussie Ark’s work to protect the broad-headed snake you can donate via their website.