This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
The National Wilderness Institute no longer exists. Its Web site has disappeared, its phone number has been disconnected and the founder has moved on to become a senior advisor for the conservative Heritage Foundation. But the legacy of the organization, founded in part to attempt to repeal the Endangered Species Act, lives on. Back in 1997 the National Wilderness Institute petitioned the U.S. Fish and Wildlife Service (FWS) to remove the Hawaiian hawk, or 'io, (Buteo solitarius) from the Endangered Species Act (ESA). FWS finally moved forward on that proposal last week, asking the public for comments on the proposed delisting.
The Hawaiian hawk joined the Endangered Species List in 1967, fewer than six months after passage of the original Endangered Species Preservation Act, the predecessor to the current ESA, which followed in 1973. The only hawk species native to Hawaii, the 'io once lived on six of the archipelago's islands. Today it can only be found on Hawaii Island (aka Big Island). The original causes of its decline are not known but appear to be linked to the settlement of Hawaii by Polynesians.
Legal protection and more than 40 years of recovery efforts seem to have helped the Hawaiian hawk. In 1967 the species's population was estimated at just a few hundred birds with a very limited range. Today FWS estimates the population at closer to 3,000—a number that seems to have been stable since 1998. As their population has grown, the hawks have also spread back over the island and now range across nearly 60 percent of Big Island.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
We have also learned a lot more about the hawk during this time. In 1967 scientists thought the bird only nested in pristine native habitat. Research conducted in the 1980s revealed that the hawk could use a much broader range of habitat; nests built in nonnative vegetation had a 65 percent success rate, compared with 77 percent in native vegetation. By the time a species recovery plan was published in 1984, FWS researchers suggested that a population of 2,000 birds would be enough to consider downlisting the species from "endangered" to "threatened" and wrote that because of the hawk's "high breeding success, the relatively low levels of predation and human disturbance, and the absence of environmental contaminants affecting the 'io, the population appears to be in a more secure condition than previously thought."
FWS itself first proposed reclassifying the hawk as "threatened" in 1993, which kicked off a few years of meetings, demographic studies and reviews. In 1997 a working group formed to study this possibility passed the issue back to FWS, saying that a simple population count was not enough to reevaluate the species's status and suggesting that trends and other threats should also be considered.
The National Wilderness Institute filed its petition to delist the hawk at about this time but FWS declined to act on the petition for more than a decade, saying that other species took a priority over the agency's scant resources.
Then, in 2009, the agency formally proposed not just reclassifying but removing the Hawaiian hawk from the endangered species list. That proposal initiated a public comment period, a normal process under the ESA. Those comments yielded new information, which, according to a filing February 12 in the Federal Register (pdf), "shows negative habitat trends due to urbanization and nonnative plant species invasion" but also identified several ongoing reforestation projects that would benefit the hawk. That proposal was withdrawn pending investigation of the data that came in during that public comment period.
Now FWS has once again proposed delisting the hawk and has launched a new public comment period, which runs through April 14. The agency seeks any additional information on the hawk and either its recovery or threats, including the bird's ecology, population trends and positive or negative effects of land management practices.
But West Hawaii Today found that many Hawaiians don't think the 'io should be delisted. The owner of an animal sanctuary told the paper that people still shoot the birds—she recently rehabilitated two hawks that had been shot with a BB gun—and that their habitat continues to shrink. Others said they see the birds less often than they did 10 or 20 years ago. The hawks are valued in Hawaiian culture as a symbol of royalty.
Even if the hawk is delisted, it will still be protected under the Migratory Bird Treaty Act, a 1918 federal law that protects about 800 species. FWS would also develop a post-delisting monitoring program that would last at least five years to survey populations and make sure that new threats do not emerge. (Hawaii is, after all, the extinction capital of the world.)
What happens next? It's hard to say. This saga has already stretched on for decades. The only thing we do know is that the Hawaiian hawk's protected status has outlasted the organization that sought to remove it. Hopefully it will survive any additional threats that emerge as well.
Photos by Pat McGrath via Flickr. Used under Creative Commons license
Previously in Extinction Countdown: