MARINE CORPS BASE HAWAII, KANEOHE BAY, Hawaii -- Mud flew from the tracks of four Amphibious Assault Vehicles, as 12 Marines from the AAV Platoon, Combat Support Company, 3rd Marine Regiment, tore through the pickleweed infestation around the Nu'upia Ponds, March 6 and 7, to improve the habitat for the endangered native Hawaiian Stilt.
For 19 years, the 26-ton machines have been plowing through the muddy waters, under close supervision by the MCB Hawaii Environmental Compliance Protection Department staff, crushing the pickleweed and destroying the mangrove roots in a training operation aimed at fighting the war on wildlife extinction.
"In the late 1970's, the AAV unit used the pond perimeter to get to Ft. Hase beach," said Dr. Diane Drigot, senior natural resource manager for the MCB Hawaii Environmental Department. "Once, the birds tried to nest in the tire tracks, so the unit became concerned and called state and federal wildlife biologists for advice."
Subsequent studies showed that the birds would benefit in an environment similar to that created by the tracks of an AAV. To create a "win-win" situation, the every day "tank trail" used by the AAV unit was moved north to avoid harm to ground stilt nests.
Once a year, though, just before nesting season, the Marines are able, under environmental staff supervision, to drive their vehicles through the mud to help the local wildlife.
"This is the first time I have done this," said Lance Cpl. Ryan Bonham, a driver for the platoon. "I thought it was a good thing that we did for the environment and the birds seem to benefit."
The Hawaiian Stilts do benefit from the two days of plowing.
In 1982, there was an estimated 60 Hawaiian Stilts in the ponds, according to Drigot, but as of January 2001, the number has jumped to 135 birds. Increased habitat for nesting with AAV help is one of the factors contributing to their increase.
"This is a unique project and has received international attention," said Mark Rauzon, senior wildlife biologist with Sustainable Resources Group International, Inc, who has helped MCB Hawaii monitor bird response to AAV work. "I wrote a paper with Dr. Diane Drigot on the progress of the birds and brought it to a conference in New Zealand. People there were pleased to see the military taking such a proactive approach in helping the wildlife."
The vehicles used a grid pattern on March 6 to break up the plants that were growing along the shore. This also made square-shaped islands that the birds could use to nest in.
On the following day, the AAV's were used to make circles in the mud. This created "donut-shaped" nesting areas also used by the birds. Both island shapes are surrounded by protective "moats" of water. These discourage access to the birds and their young by predators like the mongoose and feral cat, said Drigot. The islands also provide the young birds better access to their food, such as small fish and insects that reside in the surrounding water.
After driving through nearly 200 acres of mud, the destructive power of the AAV rendered the weeds of the ponds helpless, allowing the Hawaiian Stilt to nest in the Nu'upia Pond wildlife management area for another year.