Kau Forest

Country/territory: USA

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

Area: 44,145 ha

Audubon / American Bird Conservancy
Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2009 high not assessed low
For more information about IBA monitoring please click here

Site description
The Ka`u Forest Important Bird Area is located on the southeastern flank of Mauna Loa volcano on the island of Hawai`i. It includes about 44,146 hectares of native forest, woodland, and shrubland extending from about 600 to 2550 meters (2000 to 8400 feet) elevation. The State of Hawai`i's Ka`u Forest Reserve comprises the majority of the area, but some important habitat for native forest birds above 1500 meters elevation is owned and managed by Hawaii Volcanoes National Park. The area also includes portions of the State of Hawai`i's Kapapala Forest Reserve and Kapapala Cooperative Game Management Area. Several smaller sections are owned and managed by The Nature Conservancy of Hawaii and Kamehameha Schools. The terrain consists of gentle to moderate slopes and rocky gulches cut by streams, punctuated by steep, vegetated cinder cones in some areas. Most of the lower and middle elevations are covered in dense rainforest or mesic woodland. Rainfall is highest in the center of the area, peaking at over three meters per year from 900-1000 meters elevation, declining toward the east and west. The upper elevations become increasingly dry and rocky toward the summit of volcanically active Mauna Loa. The lower forest boundary is an abrupt, unnatural edge created by forest clearing for sugar cane plantations and cattle ranching.

Key biodiversity
The Ka`u forest 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 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 populations of `Akiapola`au, Hawai`i Creeper, and `Akepa are the second largest for these species, after those in the area centered around Hakalau Forest National Wildlife Refuge. The area also supports relatively large populations of three other endemic forest birds of global conservation concern, the `I`iwi (Vestiaria coccinea), Oma`o (Myadestes obscurus), and Hawaii `Elepaio (Chasiempis s. sandwichensis), and two more endemic forest birds that are more common but have globally restricted ranges, the `Apapane (Himatione sanguinea) and Hawai`i `Amakihi (Hemignathus virens). The Pueo (Asio flammeus sandwichensis), a subspecies of the Short-eared Owl endemic to the Hawaiian Islands, occurs throughout the area. A small number of endangered Nene or Hawaiian Goose (Branta sandvicensis) have been reintroduced in the southwestern portion of the Ka`u area. 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 Ka`u forest area. The Ka`u forest is one of the top sites being considered for reintroduction of captive-bred `Alala or Hawaiian Crows (Corvus hawaiiensis), which are currently extirpated in the wild.

Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Kau Forest. Downloaded from http://www.birdlife.org on 07/12/2022.