Hamakua Forests

Country/territory: USA

IBA Criteria met: A1, A2, A4i (2009)
For more information about IBA criteria please click here

Area: 51,168 ha

Audubon / American Bird Conservancy
Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2012 not assessed not assessed medium
For more information about IBA monitoring please click here

Site description
The Hamakua Forest Important Bird Area is located on the eastern flank of Mauna Kea volcano on the island of Hawaii. It encompasses about 51,168 hectares (126,436 acres) of predominantly native forest extending from about 450 to 2,130 meters (1,500 to 7,000 feet) elevation. The 13,252-hectare Hakalau Forest National Wildlife Refuge is the centerpiece of the IBA and was established in 1985 specifically to protect populations of endangered forest birds and their habitat. The IBA also encompasses adjacent parcels that contain additional important habitat, including Laupahoehoe State Natural Area Reserve, Hamakua, Hilo, Hilo Watershed, and Manowaiale`e State Forest Reserves, and several privately-owned parcels. Together, these lands form the single largest area of intact native forest in the Hawaiian Islands. The terrain consists of gentle to moderate slopes with steep rocky gulches cut by numerous streams. Rainfall is high throughout the area, peaking at over 6 meters per year around 500 meters elevation and declining gradually upslope. The lower and middle elevations are covered in dense `ohi`a and `ohi`a-koa rainforest. The upper elevations support mesic koa-`ohi`a woodland. The upper forest boundary in many areas is an abrupt, unnatural edge created by koa timber harvesting and clearing of forest for cattle ranching. The lower forest boundary is also abrupt in some areas due to clearing of forest for sugar cane cultivation. Most of the area is dominated by native plant species, but alien plants are common along the edges and dominate some areas, particularly at lower elevations. The dense vegetation, high rainfall, and steep stream gullies of the Hamakua region have limited human use and helped to protect it from disturbance and development, and it remains one of the most remote and little-visited areas in Hawai`i.

Key biodiversity
The Hamakua Forests IBA supports one of the most important remaining concentrations of endemic Hawaiian forest birds, including the largest populations of three species that are endemic to the island of Hawaii and listed under the U.S. Endangered Species Act, the `Akiapola`au (Hemignathus munroi), Hawai`i Creeper (Oreomystis mana), and Hawai`i `Akepa (Loxops coccineus). Several species reach their highest density in Hakalau Forest National Wildlife Refuge, which forms the core of their distribution. Although Hakalau comprises only 20% of the land area in the IBA, it harbors 50% of `Akiapola`au (50%), 49% of Hawai`i Creeper, and 72% of Hawai`i `Akepa. The endangered `Io or Hawaiian Hawk is widespread and observed frequently over much of the area. The Hamakua 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 Common (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. The endangered Nene or Hawaiian Goose (Branta sandvicensis) has been reintroduced at Hakalau Forest NWR, and about 200 birds now inhabit the area.

Recommended citation
BirdLife International (2023) Important Bird Areas factsheet: Hamakua Forests. Downloaded from http://www.birdlife.org on 29/01/2023.