Fish and Wildlife Service Proposes Delisting Hawaiian Hawk from Endangered Species List

While the Hawaiian hawk has soared in numbers over the last 40 years, its resilience is the exception for endangered native birds in Hawaii

Staff Writer Elijah Kahula
Graphics by Leah Wyzykowski

Despite its reputation as a paradise hosting thousands of unique endemic species, the Hawaiian Islands are often referred to as the world capital of extinction. As people from the rest of the world began to colonize Hawai`i, so too arrived invasive species carrying diseases. Many of these species targeted native birds for predation, driving their numbers down dramatically.

Today, the archipelago serves as a mass grave for dozens of extinct bird species. Additionally, the U.S. Fish and Wildlife Service (USFWS) currently lists 42 separate endemic bird species in its list of endangered and threatened species in the Pacific islands. Soon, however, this list may lessen by one due to a bird that seems to be thriving despite the odds: the Hawaiian hawk.

On Oct. 31, the FWS has reopened a comment period considering their proposal from 2014 to remove the Hawaiian hawk from the Endangered Species Act, citing new evidence supporting the population’s stability.

Known in Hawaiian as `io, Hawaiian hawks were one of the first birds to be put on the USFWS’s Endangered Species List shortly after it was created in 1967. Since then, they have enjoyed protection and habitat restoration efforts on both the federal and state level. USFWS has been wary of delisting the Hawaiian hawk from its status as “endangered” for a long time, believing that they could only survive in pristine, native habitats, many of which were rapidly declining.

When first studied, surveyors estimated only a few hundred Hawaiian hawks remaining on the island. Now however, their numbers are estimated to be closer to 3,000.

What accounts for this success in restoring the hawks’ numbers? Dr. Patrick Hart, an ecologist who has worked in the field of bird conservation for over 30 years and now serves as the assistant chair of the Conservation Biology department at UH Hilo, says the answer is adaptability.

“As long as they have trees, Hawaiian hawks seem not to care whether it’s native or non-native forest.” He notes that while they originally evolved to target other birds as a food source, they now also hunt for invasive species like mice and rats. Furthermore, you can find hawks in diverse environments on both sides of the island, as well as in both low and high elevations.

In the world of bird conservation, the condition of the Hawaiian hawk’s population is viewed as a rare exception. Hart cites avian malaria, which is carried by mosquitoes, as a primary reason so many native species’ populations are now in decline.

Though Hawaiian hawks are unaffected by avian malaria, Hart estimates that virtually all honeycreepers on the island will become extinct in the next century due to the disease. Feral cats have also been a driving factor and threat to bird populations, especially those that nest on the ground.

Though he notes reservations about Hawaiian hawks originally having gone extinct on all other Hawaiian islands except the Big Island for mysterious reasons, overall, Hart doesn’t currently see a strong argument against their removal from the Endangered Species Act. “They don’t seem to have the same threats as other birds have; their populations seem to be stable or increasing, and they’re found in a variety of habitats.”

To sum up the relationship of the Hawaiian hawk to the rest of bird conservation efforts in Hawaii, Hart told Ke Kalahea, “I’m not someone who’s pushing for the delisting of the Hawaiian hawk, but I would be much more engaged and up in arms if it were almost any other native bird.” In the fight against native bird extinction in Hawaii, it seems that the Hawaiian hawk may be the rare, triumphant exception.