S.O.S.
save our snails
The Hawaiian tree snail and the Kamehameha butterfly are close to extinction, but all hope is not lost BY ANNA STEPHENSON
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aving endangered snails and butterflies in Hawaii requires raising them in the safety of a lab, releasing them into carefully crafted environments where they can thrive without getting eaten by predators and then surveying them using tiny field cameras, explained biologists in the Snail Extinction Prevention Program and Pulelehua Project. Despite biologists’ best efforts, the coordinator of the SEPP said they sadly lost the last remaining snail of the species Achatinella apexfulva. His name was George. “George was … the last descendant of a handful that were found in the Ewa Forest Reserve [near Pearl City] about 30 years ago,” said David Sischo, the coordinator of the SEPP and the Pulelehua Project. He said George and other snails were brought to the University of Hawaii. He explained, “Prior to those founding individuals being discovered, the species were thought to be extinct. These were the last known individuals. “A pathogen or parasite that came through the lab caused mortality in all the individuals except for George. He was the last known individual and passed away in 2019 on New Year’s Day.” Sischo said the cause of death was likely old age. When an endangered species is down to one individual, as was the case with Achatinella apexfulva, the species is functionally extinct because they have no one to breed with. However, there is still a chance for their genes to live on. George was planned to be bred with a snail from a closely-related species,
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Achatinella concavospira. Unfortunately, Sischo said the breeding never came to pass. “It was unlikely to work anyways,” said Sischo. “It was kind of a last-ditch, Hail Mary effort. ... By the time we received approval to make that happen, he passed away. He may have been too old to reproduce anyway. We don’t really know.” Because all Achatinella species are considered endangered under the Endangered Species Act, he said any actions involving captive breeding must be approved by the Hawaii Department of Land and Natural Resources Division of Forest and Wildlife, which oversees the protection efforts. “The Hawaiian Islands had about 750 distinct species of snails that existed nowhere else in the world,” he explained. “About half our snail species have been lost already, and about 100 species are likely to go extinct soon without prevention.” Hawaii’s delicate ecosystem has been hard hit since European contact, and the Hawaii Invertebrate Program officials say it is working to reverse this. Sischo describes SEPP as a shield against extinction. Its lab on Oahu is a captive-rearing facility housing close to 40 species of snails, he said, all of whom are extinct in the wild. The endangered snails were gathered to the SEPP lab in order to grow and breed them safely away from predators and other threats. Major threats to the snails include invasive predators the snails never evolved a defense against, such as rosy wolf snails, rats and Jackson’s chameleons, Sischo explained. All
three species find the slow-moving, colorful snails to be a tasty and easy-to-get treat. At the program’s small lab complex on Oahu, there are a few trailers and gardens where several dwindling species of native invertebrates are carefully maintained. In the hopes of one day repopulating the Hawaiian Islands, Sischo said the snails are watched after in small but stable breeding populations. On both Oahu and Maui, captive-bred snails are released into special patches of land that have been searched inch by inch to remove predators, Sischo explained. They also have a predator-proof fence erected around them. The released snails, from that point, will only face the threats naturally found on Hawaii, such as heavy rain or competing with other native snails for food. Under these circumstances, the snails can thrive like they once did, Sischo said. These patches of land, called exclosures, require maintenance, which is one of the duties of SEPP intern, Lilly Thomey. She said she lives in Halawa and began working for SEPP through Kupu and Americorps. She also works to restore native habitats and survey the habitats snails were once recorded living. “A favorite story of mine is when I first camped in the northern Koolau mountain range for an overnight snail survey,” Thomey shared. “My co-workers and I spent the day working in a snail exclosure, performing upkeep duties and then set aside time to watch the sunset over the Waianae mountains with the silhouette of Kauai in the background. Once it was sufficiently
