Pūpū kani oe (Partulina physa) snail. - Photo: Courtesy of Bill Mull

In Kohala, an effort to
save native 'singing snail'

It's last known refuge is in rainy Honokāne Valley

By Liza Simon / Ka Wai Ola

The pūpū kani oe is immortalized in Hawaiian legend as the "singing snail." In the epic Lā'ie'lohelohe, the critter gets credit for contributing music to the wedding celebration of high Chiefess Kākalukaluokēwā – a romantic role that is also described in a composition of the late Nona Beamer. As it turns out, this species of tree snail is a cousin of the common 'opihi and utterly without pipes. It cannot sing. But it was once so abundant in our island forests that Hawaiians in traditional times attributed to the tiny creatures the chirping of birds.

Sam 'Ohukani'ōhi'a Gon, a scientist and cultural adviser at the Nature Conservancy, delights in telling this story as a way of putting into perspective a new 15-year conservation partnership that aims to rescue the one-of-a-kind Hawaiian tree snail species from creeping any closer than it already has to the brink of extinction. While not yet on listed officially as endangered, the native Partulina physa – as its known by its species name, has dwindled in numbers. Its last known refuge is a wet, rain-forested plateau, located 4,000 feet above Honokāne Valley in Kohala, Hawai'i Island.

Pūpū kani oe tree snails feeding on 'ōhi'a leaves. - Photo: Courtesy of Melora Purell

Under the new agreement between the Nature Conservancy and Honokāne Valley landowner Ponoholo Ranch, field studies will begin soon to determine its remaining population and identify existing threats to the creature and its habitat. This will provide information for a management plan that has already inspired not snail songs but praises for collaborative stewardship: "The pūpū kani oe was for so long a source of beauty and pride in Hawai'i. To be able to bring it back showcases cultural significance and is a shining example of what can be accomplished when many organizations work together," said Gon.

In his agreement with the conservancy, ranch owner Pono von Holt represented the interests of the Kohala Watershed Partnership, of which he is a member along with 10 other private and public landowners interested in protecting the region's water resources. They have expressed concerns that the near disappearance of the Hawaiian tree snail could be a canary in the coal mine signaling escalating environmental threats to important biodiversity, according to Jon Griffin, the Nature Conservancy's Hawai'i Island field representative.

"Biodiversity means that all the parts of nature fit together in the right and beneficial way," he said. "If you lose one part, you never know what kind of disasters can occur. But we have seen in the past that the negative impacts include the loss of watershed areas, soil erosion and even serious drought.

Map showing Pūpū Kani Oe parcel within Kohala Watershed Partnership area. - Map: Courtesy of The Nature Conservancy

The focus of the new partnership is a 96-acre parcel of Ponoholo Ranch's rugged terrain. The Kohala Watershed Partnership has already started work in the area by raising funds for fencing out wild cattle that have damaged the pūpū kani oe habitat with decades of uncontrolled grazing in the area.

Problems for the pūpū kani oe go back to the early 1900s when Hawai'i's lowland forests were cleared for agriculture and rats and other predators including the so-called "cannibal snail" were introduced by plantation owners as a form of ill-conceived "biocontrol," said the conservancy's Sam Gon.

But memories of the pūpū kani oe never entirely faded for many Hawaiians, Gon added. "The zigzag patterns on the snail shells are very beautiful. There was likely interest in gathering the creatures from the native 'ōhi'a forests," he said.

Biologists have also shed light on the benefits pūpū kani oe can bring to the complex forest ecosystem. "The snail survives by eating fungus from the tree leaves and this allows the tree to accomplish more photosynthesis. So you have a mutually beneficial relationship overall with the plant getting a good cleaning and the snail receiving a place to live," Gon explained.

The area also provides vital habitat for the 'io, the endangered Hawaiian hawk, as well as the Hawaiian owl, pueo and many other native forest birds. - Photo: Courtesy of Brooks Rownd

The management plan, which will be hammered out under the new partnership, could include weed control, removal of feral pigs and predatory species as well as the fencing off of affected koa trees. Landowner rights and access to land are not expected to be affected.

The work to save the Hawaiian tree snail marks the Nature Conservancy's first partnership with a major landowner in the Kohala area. "The conservation management agreement will enhance our ability to practice good land stewardship by combining Ponoholo Ranch resources with the expertise, experience and resources of The Nature Conservancy," landowner von Holt said in a news release. "The restoration of native forest in the Pūpū Kani Oe parcel will benefit the watershed of the Kohala Mountain, the livestock entities that depend on it and the community of Kohala."

Griffin, of the conservancy, added, "We are happy that the landowners stepped forward and we are hopeful to have more of these partnerships to support stewardship."

Overlooking Pūpū Kani Oe parcel in Kohala. - Photo: Courtesy of Melora Purell