Key Takeaways
- The Campbell’s keeled glass-snail, a species thought to be extinct since 1996, was rediscovered on Norfolk Island in 2020.
- A team of scientists and conservationists worked to establish a captive breeding program and reintroduce the snails to their natural habitat.
- The reintroduction effort involved transporting hundreds of snails from a breeding facility to Norfolk Island and releasing them into a controlled environment.
- Despite initial challenges, including a mould outbreak that killed many of the snails, the team remains hopeful that the species will thrive in its new habitat.
- The project highlights the importance of conservation efforts for invertebrate species, which are often underrepresented in conservation actions.
Introduction to the Project
On a grey day in early June, a commercial plane landed at Norfolk Island Airport in the South Pacific, carrying precious cargo from Sydney: four blue plastic crates with "LIVE ANIMALS" signs affixed to the outside. Inside were hundreds of thumbnail-sized snails, with delicate, keeled shells, that were part of an ambitious plan to bring a critically endangered species back from the brink. The Campbell’s keeled glass-snail was listed as extinct on the International Union for Conservation of Nature red list in 1996, but in 2020, Dr. Isabel Hyman, a snail scientist, received surprising photos from a Norfolk Island citizen scientist, Mark Scott, of an unusual large snail that he had found.
The Rediscovery and Breeding Program
The photos sparked excitement among the scientific community, and Hyman, along with her colleagues, made a trip to Norfolk Island in March 2020, where they found a lineup of Campbell’s keeled glass-snails hidden under a decayed palm frond. In 2021, 46 of the snails were flown to a captive breeding facility at Taronga Zoo, which the team established as the best bet to save the animal from extinction. The snails give birth to live young from the side of their necks, birthing a new baby every fortnight. Despite initial challenges, including a high mortality rate among the founding snails, the population eventually grew to more than 800 snails.
The Reintroduction Effort
By June 2023, the team was ready to attempt what they believed was the first large-scale snail translocation in Australian history. The snails were transported back to Norfolk Island, where they were held in a dedicated facility for several weeks before their release, to gradually acclimate to the food that they would eat back in the wild. However, disaster soon struck, as a mould outbreak in their holding tanks resulted in a mass die-off, killing 260 of the original 600 arrivals. The 340 surviving snails were released in late July, timed to coincide with favourable wet-season conditions, into a steep, "beautiful valley surrounded by palm trees", with native hardwoods providing shade.
Post-Release Monitoring and Conservation Efforts
The release site was chosen to match the original habitat’s temperature and humidity, and the team installed an irrigation system to add additional moisture in months of scant rainfall. National park rangers set up bait stations and traps to manage the risk of predation by invasive rodents and feral chickens. Each snail was painstakingly tagged, and PhD student Junn Kitt Foon monitored their movements every three days for the first fortnight after release. Although it has become hard to detect the snails, the team remains hopeful that the species will thrive in its new habitat. Researchers have counselled Foon that sometimes released snails disappear for a few years with no trace, only to experience a massive boom in population after a good season of rain.
Conclusion and Future Plans
The team is planning another round of snail reintroductions in 2026, and Hyman adds that they have some paperwork to file, including updating the IUCN listing to show that the Campbell’s keeled glass-snail is not extinct. The project highlights the importance of conservation efforts for invertebrate species, which are often underrepresented in conservation actions. As Melinda Wilson, natural resources program manager at Norfolk Island national park, notes, "Invertebrates are a whole group of animals that are probably underrepresented when it comes to conservation… To have these snails front and centre as part of our conservation actions… has been really rewarding." The team’s efforts demonstrate that even the smallest creatures can make a big impact, and that conservation efforts can lead to remarkable recoveries.