Northern Prairie Wildlife Research Center
PROTECTING ENDANGERED SPECIES
A heavy mist shrouds the forest in shades of gray, but it can't mask the brilliant flashes of red, yellow, and orange that dart through the branches. This is the home of the 'akepa, the 'akiapola'au, the 'i'iwi, and the 'apapane...magical names that befit these unique Hawaiian forest birds. This is Hakalau Forest National Wildlife Refuge(NWR). Managed by the U.S. Fish and Wildlife Service, the refuge was set aside in 1985 to protect and manage endangered forest birds and their rainforest habitat.
Located on the windward slope of Mauna Kea, Island of Hawaii, the 32,733-acre refuge supports a diversity of native birds and plants equaled only by one or two other areas in Hawaii. Eight of the fourteen native bird species occurring at Hakalau are listed as endangered. Sadly, seven species that were part of Hakalau's bird community when Captain James Cook landed on the island in 1778 have since become extinct. Thirteen migratory bird species and 20 introduced species, including eight game birds, as well as the endangered 'ape'ape'a(Hawaiian hoary bat) also frequent the refuge. Twenty-nine rare plant species are known from the refuge and adjacent lands. Twelve are currently listed or proposed for listing as endangered. Two endangered lobelias have fewer than five plants known to exist in the wild.
|PROVIDING ESSENTIAL HABITAT
Hakalau Forest NWR contains some of the finest remaining stands of native montane rain forest in Hawaii. The slopes below 4,000 feet receive very high rainfall--250 inches annually! Bogs, fern patches, and scrubby forest dominate this area which is dissected by numerous deep gulches. Rainfall decreases to about 150 inches at elevations above 4,500 feet, where majestic koa and red-blossomed 'ohi'a trees form a closed-canopy forest. A wide variety of common trees, shrubs and ferns occur here including 'olapa, kolea, ohelo, kawa'a and hapu'u, as well as the rare and endangered haha and oha wai. Further upslope, above 6,000 feet, rainfall decreases to 100 inches or less. The native forest merges into abandoned pastureland where alien grasses and weeds, introduced as forage for cattle, are the dominant vegetation.
RESTORING HABITAT THROUGH EFFECTIVE MANAGEMENT
Hakalau Forest NWR's goal is to promote the recovery of endangered forest birds and their habitat. Current efforts are focused in three areas:
Preventing further deterioration of the native forest
Grazing by domestic cattle has been eliminated. Management units of 500 to 2,000 acres are fenced to exclude wild cattle and pigs. Feral animals are removed from these units by drives, hunting, and trapping. Alien plants are controlled through use of herbicides, hand grubbing, and fire.
Restoring the native forest
Seedlings and cuttings of native trees, shrubs, and ferns are propagated on the refuge and planted in abandoned pasture and forest clearing to restore native habitat decimated by grazing cattle and overrun by alien grasses and weeds. Alien plant and animal removal encourages natural regeneration in areas that already support native trees and shrubs.
Documenting the status of biological resources
The health of native plant and animal populations and their responses to management efforts are monitored. Research is underway to identify the factors responsible for the decline of native plants and animals and to determine how to reverse the downtrends.
LEARNING FROM THE PAST TO PROTECT THE FUTURE
Much of Hawaii's native lowland habitat was degraded following the Polynesians' arrival over a thousand years ago. In the late 1700's, cattle, goats, and European pigs were released into the forests, and hundreds of additional alien plants, animals, and insects have subsequently been introduced. Most lowland plants seen today like the orchid, ginger, and plumeria are aliens or non-native. Mosquitoes, wasps, mongooses, cats, and rats are other examples of animal introductions that have had detrimental impacts on Hawaiian habitat and native species. Grazing pressure by cattle and pigs has resulted in the replacement of Hawaiian plants by more competitive alien grasses and shrubs within the upper portions of Hakalau Forest. Below this pasture area, the native tree canopy is still intact, but the native understory has been replaced by alien grasses, blackberry, banana poka, and English holly. The replacement process may have been accelerated by efforts to create more pasture land through bulldozing and burning, and by logging mature koa and 'ohi'a trees for timber and fence posts. Habitat loss is only one of the factors responsible for diminishing populations of native birds. Diseases carried by alien birds and spread by introduced mosquitoes; competition from alien birds and insects for food and space; and the introduction of predators such as rats, cats, and mongooses are also responsible for population declines.