Karen A. Iwamoto
WAIANAE MOUNTAIN RANGE — On a clear morning, here, thousands of feet above Schofield Barracks, a pair of conservationists from the Oahu Army Natural Resources Program scanned the sky, waiting for the approach of a Black Hawk helicopter scheduled to sling load supplies for an enclosure that will protect a population of endangered Oahu tree snails.
They heard the aircraft’s approach before they saw it. It cleared the tree line, hovered over the marked drop zone, and released its load of wooden pallets before continuing its flight back to Schofield.
Over the course of three days, from March 8 to 10, Black Hawk pilots and crew chiefs from the 2nd Battalion, 25th Aviation Regiment, 25th Combat Aviation Brigade, 25th Infantry Division, with ground and sling load assistance from the 209th Aviation Support Battalion, 25th CAB, 25th ID, delivered 21 loads of building supplies – everything from wooden pallets and plastic sheeting to a wood chipper and concrete – each load weighing up to approximately 4,000 pounds.
It would have taken a smaller, private helicopter over twice as long to drop the supplies to this remote area, which is not accessible by automobile.
Chief Warrant Officer 3 Brent W. Gregory of the 2-25th Avn. Regt., one of the pilots, said the mission allowed the team from the 25th CAB to prove its ability to successfully coordinate with flight crews, ground crews, sling load teams and drop-zone personnel. Together, they overcame challenges associated with executing unique rigging procedures, conducting long line sling load drops and negotiating delivery to an unfamiliar drop zone in the Waianae Mountain Range.
“The mission strengthened our skills as a unit by exercising our ability to conduct unique external loads in a real world environment,” he said, crediting the sling load team from the 209th ASB for ensuring the loads were rigged, certified and air worthy.
“What people don’t realize is the Army is a major conservation partner in the state of Hawaii because of the effort by OANRP to fund endangered plant, bird and snail protection work,” said Dan Sailer, natural resources manager for OANRP, which is part of U.S. Army Garrison-Hawaii’s Directorate of Public Works.
He and Jamie Tanino, a rare snail conservation specialist with OANRP, were here to assist the Soldiers with the sling loads for the so-called “snail jail,” which will be built next to another enclosure that is already home to hundreds of the endangered kahuli snails, also known as Achatinella mustelina.
The snails, which measure in at about three quarters of an inch, were once abundant in the island’s forests, Sailer said, adding that stories from generations past describe them as covering the leaves of trees “like barnacles.”
They were revered by the Hawaiian people for their beautifully patterned shells, which vary by region and range in color from yellow, orange and red to gray, black and white.
“If you look at the snails enough, you can know, ‘Oh this guy is from the (Koolau) area’ or ‘This guy is from the (Waianae) area,’” Sailer explained. “There are enough variations in the color patterns and banding patterns (on the shells).”
Hawaiian chants describe forests alive with the sound of the snails’ singing. (Scientists note that the snails do not have vocal cords, and the singing, or chirping, was likely from insects living in the snails’ habitat.)
At their peak, the tree snails thrived from sea level to the upper regions of the Koolau and Waianae mountain ranges, according to the U.S. Fish and Wildlife Service, but today are found only at elevations above 1,300 feet.
People began noticing a drop off in the number of native forest snails around the late 1950s, Tanino said.
In 1981, they were placed on the state of Hawaii’s and the U.S. Fish and Wildlife’s lists of endangered species. The Army is tasked with protecting them, along with about 100 other endangered native species within the Army’s training area.
The main threats to their existence are non-native predators, such as rats, Jackson’s chameleons and the carnivorous rosy wolf snail, as well as loss of native habitat. These challenges are exacerbated by the low fertility rate and slow maturation rate among the native snails, which are believed to reach breeding age at about 7 years old. Research has shown the snail enclosures are successful at stabilizing kahuli populations, Sailer said, noting that outside of the enclosures, there are very limited threat-control measures to prevent predators from destroying the kahuli population.
“The snails are still declining throughout the Waianae and Koolaus, except in the snail jails, so what’s been really great for me is seeing the snail jails have been working,” Sailer said. “We built … (one of the) first ones about six years ago, and now the population there is well over 1,000 and thriving.”
The Army, in partnership with the state and the U.S. Fish and Wildlife Service, manages five snail enclosures in the Waianae Mountain Range and plans to build two more, for a total of seven.