HAWAI'I'S ENVIRONMENT
Reforested land proves to be native attraction
By Jan TenBruggencate
Advertiser Columnist
When wildlife officials replanted Big Island pasture land with koa, they hoped that the native birds and insects would return.
Some natives have been populating the area for a while now, and researchers recently have gotten the first indication that endangered forest birds are beginning to use the region.
More than 230,000 trees, 208,000 of them koa, have been planted since 1987 on former cattle pastures in the Hakalau Forest National Wildlife Refuge.
Recently, biologists heard the call of an endangered native forest bird chick, an 'akiapola'au, from within the replanted forest. They also heard adult birds calling to the chick. It was not known whether the chick was hatched in a nest in the replanted forest, or whether the family moved in from nearby older forest.
It was the first time an endangered forest bird has been detected in the new forest.
The Hakalau forest was acquired for refuge use in 1985, and included forest habitat and open pasture formerly used for cattle ranching. About 4,000 acres of the 32,700 acres of the reserve were in pasture.
The remaining forested land was in varied condition, including some fairly unspoiled forest.
"The grassland area was forested 150 to 300 years ago, before cattle and ranching were established on the Big Island," said Dick Wass, the refuge manager.
Volunteer labor was a key to the control of weedy species in the region, including gorse, banana poka, blackberry and holly, which had been planted for possible sale at Christmas.
Cattle and pigs have been removed from the area, which is now fenced.
In addition to the koa, the volunteers put in 15 different species of common native forest plants and six endangered species.
Biologists have found that the native plants do better when planted under koa trees than if planted alone in open fields.
Some native plants are coming up naturally, but not as fast as researchers would like, he said. That's why other native species were planted.
Wass said more common native birds have already been seen nesting in the reforested area, but the rare insect-eating species seem to be moving in more slowly.
"It appears that it takes a while longer to develop a good insect fauna" to give these birds a food source, he said.
The 'akiapola'au is an insect eater with a deeply curved beak that is used to pry up tree bark to get at food underneath. Only about 300 of the birds are known to exist in Hakalau, and only 1,000 islandwide.
Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. Contact him at (808) 245-3074 or jant@honoluluadvertiser.com.
