Development of tree snail protection enclosures: From design to implementation

• Main Authors: Rohrer, Jobriath, Costello, Vincent, Tanino, Jamie, Bialic-Murphy, Lalasia, Akamine, Michelle, Sprague, Jonathan, Joe, Stephanie, Smith, Clifford
• Format: Report
• Language: English
• Published: Pacific Cooperative Studies Unit, University of Hawaii at Manoa 2016
• Subjects: Predator proof fence; Achatinella mustelina; endangered tree snails; snails - Hawaii; Rattus rattus
• Online Access: http://hdl.handle.net/10125/40823

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in. The Hawaiian land snails in the endangered, endemic genus Achatinella have experienced major declines in population and distribution over the last 100 years. Threats to Achatinella today include invasive, non‐native predators (Euglandina rosea, Rattus rattus and Trioceros jacksonii), habitat degradation due to human disturbance and possibly climate change, and historically, collection by humans. The O‘ahu Army Natural Resources Program (OANRP) is required to stabilize select remaining populations of A. mustelina. Stabilization goals are to maintain 300 mature snails at eight managed sites and control threats within sites. This report describes OANRP efforts to combat invasive predators by means of predator‐free and ‐proof snail enclosures. A couple of prior attempts at excluding predatory snails were marginally successful but the identification of additional predators required substantial additional barriers. The design and construction of the enclosure at Pu‘u Hapapa is used as a case study. This report includes detailed information on the physical development of predator‐proof barriers, construction and costs. Additional needs for monitoring and maintenance, predator removal, Achatinella reintroduction, Achatinella population monitoring, and habitat improvement were also developed. Funded by: U.S. Army via U.S. Army Corps of Engineers Cooperative Agreement W9126G-10-2-0017