Hawaiian Stilt Reclassified from Endangered to Threatened After Conservation Success

Imagine a bird that was so close to extinction that there were only a few hundred left in the entire world. But then hardwork of scientists and magic of innovation brought them back in large numbers and the same bird is now thriving across parts of its native habitat decades later. That remarkable comeback is that of the aeʻo, or Hawaiian stilt, a graceful, long-legged shorebird whose recovery is now being hailed as one of Hawaii’s conservation success stories. According to reports, after more than 50 years of habitat restoration and wildlife management, the aeʻo has reached a major milestone on its journey to recovery. The U.S. Fish and Wildlife Service has reclassified the bird from endangered to threatened under the Endangered Species Act.

From just 200 birds to over 1,500

It has been reported that the aeʻo was once common throughout the Hawaiian Islands, but its numbers fell dramatically in the 20th century. By the 1940s experts thought there were only about 200 birds left in the wild. That number has since ballooned to over 1,500, a dramatic increase achieved through decades of coordinated conservation efforts. The new classification reflects the steady recovery of the species, but also notes that it still needs protection. The announcement was made in the Federal Register earlier this month.

Why the Ae'o nearly disappeared

The U.S. Fish and Wildlife Service and its findings

While the Hawaiian stilt is on the brink of extinction from a variety of anthropogenic and environmental factors, historically, overhunting and conversion of wetlands to agriculture and urban development destroyed much of the birds’ natural habitat, the report states. Meanwhile, invasive predators such as rats, mongooses, cats and other introduced animals preyed on eggs and chicks, making successful breeding increasingly difficult. In 1973, the aeʻo was listed as endangered, recognizing the severity of the decline, and long-term recovery programs were put in place to protect the birds and their habitat.

Encouraging results after 50 years of research

According to online media reports, new scientific research led by the University of Hawaii at Mānoa’s College of Tropical Agriculture and Human Resilience supports the decision to downlist the species. Published in the journal Ornithological Applications, the study analyzed more than 50 years of nesting records from over 2,000 nests across nine wetlands on Oʻahu from 1963–2020 and the researchers found consistent improvements in nest success and chick survival over time, evidence that habitat restoration and predator management have been key to the bird’s recovery.

Wetland restoration was the difference

If conservationists are to be believed they credit restoring wetlands with being a major factor in the aeʻo's comeback. It is said that decades of rehabilitation of degraded wetlands, careful management of water levels and control of invasive predators have created safer breeding grounds. Scientists have also seen birds quickly return to restored wetlands, including Indigenous wetland agricultural systems that once were part of Hawaii’s traditional landscapes. “This is a bright spot story,” said Melissa Price, associate professor in the University of Hawaii’s Department of Natural Resources and Environmental Management.

U.S. Fish and Wildlife Service has proposed a species-specific rule to allow habitat restoration and management activities to continue while maintaining protections under the Endangered Species Act to facilitate continued recovery. “This is just a step in a much longer conservation journey,” said lead author Jessica Idle, manager with the University of Hawaii at Manoa’s Pacific Cooperative Studies Unit. But downlisting is not the end of the work. It means the work is working. “Continued monitoring and management, particularly by increasing protected wetland habitat, will be critical for maintaining population growth.”