Post-implementation assessment of novel rodent control devices for protection of high elevation endangered species at Hawai`i Volcanoes National Park

• Main Authors: Coad, Heather, McDaniel, Sierra, Misajon, Kathleen, Forbes-Perry, Charlotte
• Format: Report
• Language: English
• Published: Pacific Cooperative Studies Unit 2017
• Subjects: Invasive rodent; self-resetting trap; endangered species; Rattus rattus
• Online Access: http://hdl.handle.net/10125/61852

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. Invasive species, including rats, threaten the existence of many of Hawai`i’s native species pushing them to the brink of extinction. Hawai`i Volcanoes National Park has a long history of successfully managing ecosystems and providing rare species habitat through systematic invasive species control. Landscape level rodent control is prohibitively expensive; however, localized control has proven cost-effective while providing significant resource benefit. A trapping program using self-resetting Goodnature® A24 technology was implemented at two remote sites in Hawai`i Volcanoes National Park in an effort to protect five endangered plant species and three endangered bird species from black rat (Rattus rattus) predation. This trapping method has been successfully implemented on other islands, but implementation requirements are site specific. Techniques and maintenance schedules were investigated specifically for subalpine dry shrubland environments and also high elevation wet forest environments. Trap performance, recommended grid spacing, and a new chocolate long-life lure formula were evaluated over the course of this investigation. Apparent rodent control trends and subsequent native species responses were captured over the course of four months by conducting biweekly trap visits and analyzing motion triggered camera footage. Clear declines in rodent activity were documented at each site during the four month intensive monitoring period. At least 38 rodents were removed from the subalpine dry shrubland test site during this period, while at the high elevation wet forest site at least 102 rodents were removed. It is suspected that the number of total kills was underestimated using available monitoring techniques. Trapping activity appeared to prevent major damage to flowers and diminish damage to fruit of endangered Campanulaceae species at the forested test site, however it ...