The Hawaiian stilt – known in Hawaiian as the Aʻeo – has been reclassified from endangered to threatened under the US Endangered Species Act, marking a rare conservation milestone for a native Hawaiian species that once numbered fewer than 200 individuals.

The US Fish and Wildlife Service published the reclassification in the Federal Register alongside a new study led by researchers from the University of Hawaiʻi at Mānoa’s College of Tropical Agriculture and Human Resilience, published in Ornithological Applications.

The research draws on more than five decades of data – representing more than 2,000 nests across nine wetlands on Oʻahu between 1963 and 2020 – and documents measurable improvements in nesting and chick fledging success over time. It’s a case study that provides crucial evidence that predator control, habitat restoration, and sustained management are key to driving recovery.

Once abundant across the Hawaiian Islands, the long-legged waterbird was pushed to the edge by overhunting, wetland loss to agriculture and development, and invasive predators. By the 1940s, fewer than 200 a’eo remained.

Listed as endangered in 1973, the population has since climbed to more than 1,500 birds today.

“This is a bright spot story,” said Melissa Price, associate professor in the Department of Natural Resources and Environmental Management at CTAHR. “So many species across Hawaiʻi are in decline. The aeʻo demonstrates how community can work in partnership with conservation managers to achieve recovery and rebuild relationships with our native species.”

Expanding managed wetland habitat remains the key to continued recovery. The Aʻeo readily colonises restored wetlands and has recently been documented nesting in restored Indigenous wetland agro-ecosystems – placing cultural stewardship and ecological recovery on the same ground. As sea-level rise threatens existing coastal wetlands, these community-led restoration efforts offer both new habitat and a model for long-term stewardship.

The reclassification is accompanied by a species-specific rule that allows habitat management and restoration activities to continue even where they might otherwise be restricted under the Act, preserving the flexibility that the partnerships behind the recovery depend on.

The authors have described the Aʻeo as a ‘conservation success story in progress’. The species remains reliant on these conservation efforts, and dependent on continued predator control, water management and habitat protection to sustain the gains made over five decades.

“Downlisting doesn’t mean the work is done,” said lead author Jessica Idle, a manager with the UH Mānoa Pacific Cooperative Studies Unit. “It means the work is paying off. Continued monitoring and management, especially expanding protected wetland habitat, will be essential to keep the population growing.”

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