Haleakalā National Park (HALE) on Maui Island encompasses 12,215 ha (30,184 acres) of Mount Haleakalā and contains populations of endangered ʻuaʻu (Hawaiian Petrel, Pterodroma sandwichensis) and nēnē (Hawaiian Goose, Branta sandvicensis). Predation by non-native mammals including feral cats (Felis catus), mongooses (Herpestes auropunctatus), and rats (Rattus sp.) has been identified as a factor limiting the population growth and survival of these species. Predator control for the protection of ʻuaʻu and nēnē has been ongoing at HALE since the 1970s, and has been effective in maintaining a relatively low rate of mortality from predators. HALE is currently developing a Predator Control Management Plan, which will guide managers in developing and implementing predator control trapping strategies to protect ʻuaʻu and nēnē as well as other endangered birds. Methods other than trapping (predator exclusion fencing, hunting, toxicants and GPS-collared sentinel cats) were considered but were deemed less practical, less effective, or financially infeasible at HALE. The Predator Control Management Plan gives resource managers the tools to prioritize and maximize predator control effort using the Decision Making Process for Predator Control as a guide.
1. Survey for predator activity
2. Identify predator hotspots
3. Assess characteristics of the hot spot
4. Create and execute a local trapping plan
5. Monitor traps
One of the biggest challenges to the trapping program at HALE is the large size of the park (12,215 ha; 30,184 acres), with about half that area containing ʻuaʻu and nēnē habitat. Other challenges are accessibility of areas and staff limitations. To improve the efficacy of the predator trapping program, strategy is evolving from an extensive, constantly armed trapping presence to targeted predator monitoring and trapping.
In 2016, field trapping methods were evaluated by Island Conservation and historical trapping data from 2000-2014 were analyzed by USGS. Utilizing the results, the Decision Making Process for Predator Control was developed as a guide for managers as part of the HALE Predator Control Management Plan.
Prioritizing areas for predator survey and trapping considers data on endangered bird nesting habitat as well as predator home ranges.
In addition, management considerations of staffing, accessibility, remoteness, and cost are incorporated. Priority areas for trapping (1) are important nesting areas for ʻuaʻu and nēnē, (2) encompass or contain predator hot spots, and (3) are accessible by hiking, ground transportation or both.