Partulina physa, a beautiful tree snail endemic to hawaii island, was once so abundant in the kohaladistrict, that historical accounts describe shell collectors riding up to trees on horseback filling…

The U.S. Department of the Interior Fish and Wildlife Service Region 1 awarded a $666,667 Project Grant to the Hawaii Department of Land and Natural Resources (DLNR) under the Competitive State Wildlife Grant (C-SWG) Program (CFDA 15.634) to help safeguard the critically endangered Partulina physa tree snail on Hawaii Island. DLNR will partner with the Kohala Watershed Partnership and Parker Ranch to establish a predator-proof fence and translocate Partulina physa individuals to a protected habitat area where diverse host plants will be planted to mitigate the impacts of the Rapid Ohia Death disease. These actions aim to immediately reduce the risk of extinction for this endemic Hawaiian tree snail species, which has experienced severe population declines due to habitat loss and invasive predators.

Partulina physa, a beautiful tree snail endemic to hawaii island, was once so abundant in the kohaladistrict, that historical accounts describe shell collectors riding up to trees on horseback filling theirsaddlebags with shells. Today the species is on the very brink of extinction due to habitat loss andextreme pressure from introduced predators such as carnivorous snail species in the genus euglandina, jacksons chameleons, and rats. P. Physa is only known to persist on portions of parker and ponoholoranches, both private working cattle ranches on the slopes of kohala mountain. The snails mostly occurmarooned in lone, old-growth, ohia trees in cattle pasture surrounded by grass. We believe the snails havepersisted in these trees in part because the lone trunks are a small target for introduced predators like thecannibal snail euglandina rosea, and because predators like rats and jacksons chameleons may be lessinclined to cross large open areas of grass. Recently, rapid ohia death (rod), a fungal disease killingmillions of ohia trees on hawaii island, has been detected on the ranch land where p. Physa arepersisting. When these trees DIE of old age or succumb to rod, the snails will perish as well. IT is clearthat p. Physa is on borrowed time, and urgent action is required to secure its existence.here we propose to partner with the kohala watershed partnership and parker ranch to establish apredator-proof fence on the ranch. Once free of predators, individuals will be directly translocated to theprotected area. The habitat within the fence will be out-planted with a diverse assemblage of snail hostplants to safeguard the habitat from rod, should ohia trees inside perish due to the disease. Theseactions will immediately and drastically reduce the risk of extinction of partulina physa.