The Mauna Loa-Kilauea Forests Important Bird Area is located on the island of Hawaii and encompasses the eastern flank of Mauna Loa Volcano and lands surrounding Kilauea Volcano. Both these volcanoes are active, and Kilauea has been erupting continuously since 1983. The IBA includes about 109,068 hectares extending from 500 to 7,000 feet (150 to 2,130 meters) elevation. Land parcels within the IBA include all or part of Hawai`i Volcanoes National Park, Pu`u Maka`ala, Kahaualea, and Waiakea 1942 Lava Flow State Natural Area Reserves, Kipuka Ainahou State Nene Sanctuary, Upper Waiakea Bog Sanctuary, Mauna Loa, Ola`a, Waiakea, Upper Waiakea, and Wao Kele O Puna State Forest Reserves, Kulani State Correctional Facility, and Keauhou Ranch and other private lands owned by Kamehameha Schools. The terrain consists of gentle to moderate slopes, punctuated in some areas by volcanic craters and vents. Areas of older lava are densely vegetated, but lands downslope from active volcanic vents are barren and covered by recent lava flows. Moisture-laden northeasterly tradewinds cause rainfall to be higher on the eastern slopes, peaking at over 150 inches (4 meters) per year around 2,000 feet (600 meters) elevation. Dense rainforest covers most of the eastern portion, grading into mesic woodland, shrubland, and grassland in leeward areas to the west. Native plants dominate many areas, but alien plants are widespread, particularly at lower elevations. The western boundary of the IBA follows the 7,000-foot (2,130-meter) contour, because land above this is mostly barren lava. The northern edge follows the boundary between lava flows from Mauna Loa and Mauna Kea, which often coincides with the Saddle Road. The Mauna Kea Wet Forests IBA is a short distance to the north. The Kau Forests IBA, which occupies the southwestern flank of Mauna Loa, is separated by intervening areas of barren lava and open grassland cleared for cattle ranching and sugar cane cultivation.
The Mauna Loa-Kilauea Forests Important Bird Area supports one of the most important remaining concentrations of endemic Hawaiian birds, including populations of four species that are endemic to Hawaii Island and are listed under the U.S. Endangered Species Act, the `Akiapola`au (Hemignathus munroi), Hawai`i Creeper (Oreomystis mana), Hawai`i `Akepa (Loxops coccineus), and `Io or Hawaiian Hawk (Buteo solitarius). The `Akiapola`au, Hawai`i Creeper, and `Akepa are sparsely-distributed and occur only in native forest above 5,000 feet (1,500 meters). The `Io is widespread and is seen frequently over much of the area. The Mauna Loa-Kilauea area also supports important populations of three other endemic Hawaiian forest birds of global conservation concern, the `I`iwi (Vestiaria coccinea), Oma`o (Myadestes obscurus), and Hawaii `Elepaio (Chasiempis s. sandwichensis). The `Apapane (Himatione sanguinea) and Hawai`i `Amakihi (Hemignathus virens) are the most abundant native birds in the IBA and also occur on other islands, but still have globally restricted ranges. Hawai`i is the only island on which the Nene or Hawaiian Goose (Branta sandvicensis) was never extirpated, and the wild Nene population has been augmented in several locations with numerous captive bred birds, particularly in Hawai`i Volcanoes National Park. Small numbers of the Hawaiian Petrel (Pterodroma sandwichensis), another endangered species endemic to the Hawaiian Islands, are known to transit the area while commuting to nesting areas higher on Mauna Loa, and it is possible that a few petrels nest along the top margin of the IBA.
Habitat and land use
The Mauna Loa-Kilauea Forests Important Bird Area is located between 500 and 7,000 feet (150 and 2,130 meters) elevation on the eastern side of the island of Hawai`i. The terrain in this area consists of gentle to moderate slopes, punctuated in some areas by volcanic craters and vents. The distribution of habitats is determined by age and chemical composition of the lava substrate, elevation, and rainfall. Recent lava flows downslope from active volcanic vents are covered by barren lava that is slowly colonized by pioneer species such as `ohi`a (Metrosideros polymorpha), `ohelo (Vaccinium spp.), and a variety of ferns. Gradual weathering of lava produces soil that allows establishment of more diverse and complex plant communities. Moisture-laden northeasterly tradewinds cause rainfall to be higher on the eastern slopes, peaking at over 150 inches (4 meters) per year around 2,000 feet (600 meters) elevation. Areas with high rainfall are covered in dense rainforest. `Ohi`a is the dominant canopy tree in this habitat type, and other common tree species include `olapa (Cheirodendron trigynum), kolea (Myrsine lessertiana), pilo (Coprosma spp.), loulu fan palms (Pritchardia spp.), tree ferns (Cibotium spp.), and a variety of non-native plants such as strawberry guava (Psidium cattleianum). Mesic forest and woodland occur in drier leeward areas to the west and at higher elevations. Koa is a dominant canopy tree in this habitat, and mamane (Sophora chrysophylla), naio (Myoporum sandwicense), and non-native fire tree (Myrica faya) are also common in some areas. Areas of lowest rainfall support open shrubland and grassland where `a`ali`i (Dodonaea viscosa), pukiawe (Leptecophylla tameiameiae), and `ohelo are the dominant plant species.
Most of the land comprising the Mauna Loa-Kilauea Forests Important Bird Area is used for conservation purposes. Hawai`i Volcanoes National Park is also used for scientific research and public education and outdoor recreation. The park contains the Hawai`i Volcano Observatory, the Kilauea Field Station of the U.S. Geological Survey, visitor centers, campgrounds, hiking trails, a hotel and other visitor services, and numerous other buildings for management and research purposes. Entry into the Pu`u Maka`ala, Kahaualea, and Waiakea 1942 Lava Flow State Natural Area Reserves is restricted by permit to protect delicate natural ecosystems and prevent the spread of invasive species. Kipuka Ainahou State Nene Sanctuary and Upper Waiakea Bog Sanctuary are also used primarily for conservation. The state forest reserves are used for conservation in addition to other purposes, such as public hunting and hiking. The Kulani State Correctional Facility contains important high-elevation forest bird habitat that is managed for conservation in a manner compatible with its primary use as a prison. Privately-owned lands on Keauhou Ranch are used for a variety of purposes, including conservation, forestry, and cattle ranching. Other lands owned by Kamehameha Schools are leased to the Zoological Society of San Diego and contain the Keauhou Bird Conservation Center. Birds raised in this facility are released into the wild to re-establish or augment wild populations, and may also be viewed by school groups for educational purposes. The Ola`a-Kilauea Watershed Partnership was formed in 1994 between federal, state, and private landowners as a cooperative land management effort to protect and restore native ecosystems. At 169,000 hectares, the partnership encompasses most of the land included in the Mauna Loa-Kilauea IBA, as well as additional parcels, and consists of all major land owners in the area.
Pressure/threats to key biodiversity
The greatest threats to birds in the Mauna Loa-Kilauea Forests IBA are diseases carried by alien mosquitoes, invasive alien plants, alien ungulates, predation by alien mammals, and logging. Abundance of endemic forest birds is higher above 1,500 meters elevation because the parasite that causes avian malaria and the alien mosquito that carries malaria and avian pox cannot tolerate cold temperatures. `Akiapola`au, Hawaii Creeper, and `Akepa occur only above 1,500 meters. Nectarivorous `I`iwi and `Apapane move altitudinally in search of flowering trees and can be exposed to diseases when they descend. Global warming may allow mosquitoes to increase in range, reducing the amount of disease-free habitat. Feral pigs degrade native forest by uprooting understory plants, preventing regeneration of native trees, spreading the seeds of invasive alien plants, and creating wallows where mosquitoes breed. Hollowed trunks of tree ferns toppled by feral pigs are the primary breeding site for mosquitoes in some areas. Invasive alien plants displace native plants needed by forest birds for nesting and foraging and often grow in monocultures that reduce floristic diversity. Some of the worst invasive plants are strawberry guava, fire tree, Tibouchina urvilleana, and christmasberry. Black rats are the most serious predator on nests of many forest birds. Mongoose (Herpestes auropunctatus) and feral cats are the most serious predators on ground-nesting Nene and Hawaiian Petrels. Koa trees are logged on some private lands. Most of Hawai`i Volcanoes National Park is fenced against ungulates and predators are controlled in parts of the park. The Ola`a-Kilauea Watershed Partnership is working to protect native habitats through fencing and control of invasive plants and feral pigs. Collisions with vehicles are a cause of mortality for Nene, and this problem is exacerbated by public feeding even though this practice is prohibited.
Lands comprising the Mauna Loa-Kilauea Forests Important Bird Area are owned by several different government agencies and private groups. The single largest parcel within the IBA is a portion of Hawai`i Volcanoes National Park, but the State of Hawai`i owns the largest proportion of the IBA overall. State lands include all or part of Pu`u Maka`ala, Kahaualea, and Waiakea 1942 Lava Flow Natural Area Reserves, Kipuka Ainahou Nene Sanctuary, Upper Waiakea Bog Sanctuary, Mauna Loa, Ola`a, Waiakea, Upper Waiakea, and Wao Kele O Puna Forest Reserves, Kulani Correctional Facility, and unencumbered lands between Kahaualea and the national park. Kamehameha Schools owns two parcels within the IBA, Keauhou Ranch and a smaller parcel leased to the Zoological Society of San Diego that contains the Keauhou Bird Conservation Center.