Successful release for unique Norfolk Island snail | Parks Australia

Tuesday 23 December 2025

Once thought extinct, a tiny snail found only on Norfolk Island is making a remarkable comeback thanks to a world-first captive breeding and translocation project.

A small population of Campbell's keeled glass snail (Advena campbellii) was found in a single location on the island in early 2020. The thumbnail-sized snails had not been seen for more than 20 years, and they were believed to be lost forever.

The rediscovery of Advena campbellii sparked a recovery program led by the Australian Museum, in partnership with Taronga Conservation Society, Parks Australia, Western Sydney University and Norfolk Island Regional Council.

One of the keys to the recovery was the establishment of Australia's first snail breeding program by Taronga Zoo Sydney. The team began with 46 snails in 2021, and four years later, the captive population had topped 800.

In June, a population of the captive-bred snails were flown to Norfolk to quarantine and acclimatise, and at the end of July, 340 were released into a secluded valley inside Norfolk Island National Park.

Ongoing monitoring of the snails in their new home has shown that they are off to a steady start, and are even breeding, with researchers recording a number of baby snails at the site.

Several Campbell's keeled glass snails sitting on concrete, some climbing a glass wall. They have dark shells that reflect light in a rainbow of colours, like an opal.

Location, location, location

Choice, preparation and ongoing management of the release site are all vital to the species' survival.

The national park team found potential four locations in the park, then chose one that most closely matched the place where the snails were originally found for features including vegetation, temperature, humidity, and predator abundance.

To maintain the moist conditions that Advena campbellii favours, park staff installed an irrigation system to help get them through dry periods.

Acting Norfolk Island National Park Manager, Melinda Wilson said ongoing predator control was extremely important.

"Rodents and feral chickens are a huge threat to our native snails, so we have set up extra bait stations and mechanical control devices for rats in and around the release site, and we stepped up control of feral chickens in the wider area,” she said.

"Invertebrates are a group that don't often get the recognition they deserve, but in this case, Advena campbelli has been front and centre of our conservation efforts for a couple of years now.

"It's been a long path, and seeing the snails arrive on the island and then be released into their new home was such an exciting and emotional time for everyone involved.

"We have learned a lot from this project, and it will continue to inform our conservation efforts into the future.

"I'm so very proud of this team and what we've achieved.”