O‘ahu tree snails return to Hawaii forests after 33 years in captivity
The Achatinella fuscobasis species was reintroduced to a protected enclosure in the Ko‘olau Mountains following decades of laboratory breeding.
The O‘ahu tree snail, a species once considered lost in the wild, was released into a protected area in the Ko‘olau Mountains on December 10, 2024, according to a Times of India report. The first group of Achatinella fuscobasis was placed inside a specially prepared enclosure in the Honolulu Watershed Forest Reserve on O‘ahu.
The Hawaii Department of Land and Natural Resources (DLNR) announced the reintroduction on December 18. This move follows more than 33 years of captive breeding after conservationists rescued the final 11 known individuals of the species in 1991.
The species declined due to predators, including the rosy wolf snail, which was introduced in the 1950s to control the invasive giant African land snail. While intended to manage garden pests, the predatory snail also hunted native Hawaiian snails. Other threats include rats, New Guinea flatworms, and Jackson's chameleons.
To protect the snails, conservationists spent five years preparing a quarter-acre exclosure. The site features five-foot-high polyethylene walls, copper wire mesh, and a hood barrier to keep out predators. The DLNR's Snail Extinction Prevention Program grew the captive population to over 1,000 individuals to facilitate this return.
The reintroduction involved partnerships between the DLNR, the US Fish and Wildlife Service, the University of Hawaii, and volunteers. A second group of snails was scheduled for release in February 2025.