but climate change is now carrying new threats up its slopes.
From our vantage point, roughly a mile above sea level, the land below us undulates, covered in a verdant carpet of impenetrable green. Our small yellow dragonfly of a helicopter, a four-seater Hughes 500D, bucks and bounces through turbulence, as we climb along a deep gash in the eastern side of Haleakalā, the 3,055-meter-high (10,023-foot) shield volcano that dominates Maui’s eastern lobe. Below us unfurls the remote Kīpahulu Biological Reserve, part of Haleakalā National Park and one of the United States’ most pristine yet threatened biological sanctuaries. Through occasional breaks in the vegetation, we can see boulder-strewn streambeds and towering cliff faces in the rugged and unforgiving landscape.
Few members of the public have ever been allowed to visit this remote sanctuary. But after years of inquiries, I was invited to join a scientific expedition into the valley. Leading the trip is 42-year-old Seth Judge, a wildlife biologist from the University of Hawai’i at Hilo. He sits beside me, snapping photos and taking videos of the forbidding terrain, where he has been conducting bird surveys for the past two years. “Look at this place,” Judge says through radio static and the percussive thwack of the blades. “It never gets old coming up here.”
It’s no accident that the Kīpahulu Valley is one of Hawai’i’s last bastions of near-pristine biodiversity. This massive erosive scar running down Haleakalā’s eastern flank is more than 750 meters (2,500 feet) deep in places. That challenging topography makes it an almost perfect natural fortress, protected by near-vertical cliffs and dense vegetation. The terrain has isolated the valley, keeping its ecosystems mostly intact while driving a stunning adaptive radiation of unique organisms. “A lot of species are endemic here because they were able to evolve without interference from species from the rest of the island,” says Woody Mallinson, Haleakalā’s natural resources program manager. Today, as many as 13 threatened and endangered species of animals and more than 40 species of plants inhabit its roughly 3,400 hectares (8,500 acres). Dozens are found nowhere else on Earth; dozens more have disappeared. “For some of the listed species, they are historic and haven't been seen in decades,” Mallinson says.