Rarely do species presumed extinct reappear with renewed hope for a better future. But researchers in Australia not only discovered a wild population of Campbell’s keeled glass-snail on Australia’s Norfolk Island in 2020 — they’ve now bred the snail in captivity and recently released more than 300 individuals back into the wild, where they’re multiplying.
This translocation, according to the Australian Museum, is the first large-scale reintroduction of a snail species in Australia.
Officially, Campbell’s keeled glass-snail (Advena campbelli) is still listed as extinct on the IUCN Red List, based on a 1996 assessment. In Australia, it’s considered critically endangered.
In 2020, Isabel Hyman and colleagues from the Australian Museum, with the help of a Norfolk Island resident, confirmed there was still a small population of the snail living in a sheltered rainforest valley in Norfolk Island National Park.
To boost its survival prospects, organizations including Sydney’s Taronga Zoo, Norfolk Island National Park, Western Sydney University and the Australian Museum started collaborated on a snail-breeding program at Taronga Zoo in 2021.
The teams knew very little about the snail’s life history, diet, behavior, or what negatively impacts it, Hyman told Mongabay by email. But with “a lot of careful, painstaking work and record keeping from the husbandry team,” they began seeing progress, she said.
The zoo-bred population of Campbell’s keeled glass-snail has now grown to more than 800 individuals. In June, the teams flew about 600 snails to Norfolk Island, which sits in the South Pacific, closer to New Zealand than to the Australian mainland. A month later, they released 340 of the snails, each marked with an ID label, into a part of the national park where the species was once found.
The conditions of the release area closely resemble the ones where the wild population lives, Hyman said. “None of our chosen release sites overlap with the wild population. This was intentional; in order to mitigate the risk of extinction for the species, we felt it better to establish our second population in a different area of the National Park.”
The team prepared the release area by installing rodent traps and cameras to monitor predator levels. It also has a sprinkler system, Hyman said, for use when conditions become dangerously dry for the snails.
Since the release, the team has observed several newborn snails. “We realize that it is still early days and that the population needs more time to become fully established,” Hyman said. “However, the fact that we are seeing live snails including some neonates at the site is promising. We have not seen many signs of rodent predation, which is also promising.”
Hyman added they’re planning another reintroduction in June 2026 at the same site, “to bolster the new population and give it the best possible chance of becoming established.”
Banner image: A Campbell’s keeled glass-snail with a number tag. Image courtesy of Junn Kitt Foon.
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