"The stream comes down to the shore from Ko‘iahi [a place in Mākua Valley]. It is that stream where the mo‘o comes down when the heavy rains fall and the stream is full of water."
– Excerpt from The Mo‘o of Mākua Valley
Terrestrial and Aquatic Ecosystems
Glossary Terms
In this ecological characterization of the Wai‘anae moku, the mauka ecosystems are those that are on land or found within the streams. The terrestrial and aquatic resources in the mauka portions of the Wai‘anae moku provide an important foundation for culture and community life. This section discusses ecosystems in the forests and streams, lowland ecological communities, threats to the ecological resources, and plans that have been developed to protect these resources.
Habitat types are classified according to elevation, then moisture, and finally dominant community members and prominent vegetation (Juvik and Juvik 1998). The state of Hawai‘i has 150 different identifiable habitat communities. Within each ecological zone, habitat can be classified as dry, mesic, or wet depending on the amount of rainfall. The Wai‘anae moku contains coastal, lowland, and montane elevation zones.
The aquatic ecosystems that exist in the moku are primarily stream resources in the upper elevations of the mountains. Hawaiian streams have relatively few native species; there are only five native fish, two native shrimp, and a few native snails. An interesting fact about Hawaiian streams is that all of the native fish and crustaceans of Hawai‘i's freshwater systems spend portions of their lives in marine or estuarine environments, moving into streams for the adult stages of life (Oki and Brasher 2003). Organisms with this characteristic are called "amphidromous."
The indigenous ‘ilima, Sida fallax.
Source: Dr. Gerald Carr, UH Manoa, Botany DepartmentThe Wai‘anae moku provides habitat for over 100 species of native and endemic plants, birds, insects, and stream life. In addition to being important components of the native habitat, many of these species are important to the Hawaiian community for cultural practices such as hula, medicine, and ceremonies. For example, maile leaves are used in making leis for weddings and other important events while ‘ilima flowers were used in leis traditionally reserved for royalty.
Threatened and Endangered Species
Some plant and animal species cannot adapt rapidly to changes in their environment, such as the effects of fire, development, or removal of forested areas. Species that have not adapted and whose populations are at critically low levels have been listed by the federal government in an attempt to provide them additional protection from direct and indirect harm. These species are called threatened and endangered species. Endangered species are defined in the federal Endangered Species Act as any species that is in immediate danger of extinction throughout all or a significant portion of its habitat range. Threatened species are not in immediate danger of extinction but are considered likely to become endangered species in the foreseeable future (USFWS 2003). There are over 50 threatened and endangered plant and animal species found in the Wai‘anae moku (see table).
The endangered O‘ahu tree snail, Achatinella mustelina.
Source: U.S. Geological SurveySome of the most critically endangered species found in the moku are the O‘ahu tree snail, O‘ahu ‘elepaio, and native ‘akoko.
O‘ahu Tree Snail (Achatinella mustelina). O‘ahu tree snails were once so prevalent that they were used to make beautiful shell leis. Currently, A. mustelina is the most abundant of the 41 remaining endangered O‘ahu tree snail genus, and it lives only in the Wai‘anae Mountains. These nocturnal fungus grazers average about ¾-inch in length when mature and have shell colors ranging from brown to yellow, green, red, and black. Adults are hermaphroditic, and fertility and growth rates are low. O‘ahu tree snails are attractive to predators like the carnivorous snail (Euglandina rosea) and rats. Recently, the flatworm (Platydemus manokwari) has significantly reduced snail populations. While O‘ahu tree snails have been observed feeding on nonnative fungus, it is unknown whether this fungus provides adequate nutrients to provide for long-term stability of the population (USFWS 2004a).
The population of O‘ahu ‘elepaio in the Wai‘anae range has dwindled to an estimated 1,000 individuals.
Source: U.S. Geological Survey‘Elepaio (Chasiempis sandwichensis ibidis). The O‘ahu ‘elepaio is a member of the monarch flycatcher family and is found only on O‘ahu. Adults are generally brown with white underparts, wing bars, tips, and rump, and light brown striping on the breast. The O‘ahu ‘elepaio is nonmigratory and territorial, and its current habitat includes limited areas of streamside vegetation and tall canopies with diverse understories. There are only about 1,000 birds remaining in the Wai‘anae range, and overall, they are estimated to occupy only four percent of their original range (USFWS 2001; Hawaii Audubon Society 1997).
In Hawaiian legend, ‘elepaio helped canoe makers judge the quality of koa logs that were made into canoes. If the bird landed on the log and pecked at it, the wood was considered to be of poor quality. If it landed on the log and simply sang, the log was considered sound. Since the ‘elepaio is an insect eater, its ability to identify insect-infested wood made it a valuable resource to early Hawaiians (Oahu Nature Tours 2004).
The endemic ‘akoko (chamaesyce celastroides var. kaenana) is limited to only a few locations on O‘ahu.
Dr. Gerald Carr, UH Manoa, Botany Department‘Akoko (Chamaesyce celastroides var. kaenana, Chamaesyce kuwaleana). There are many types of native ‘akoko, several of which are listed as endangered species. The typically shrubby plants have a milky sap and can grow in habitats as diverse as coastal dry lowlands and exposed cliffs. The kaenana variety was historically known to inhabit the northwestern portion of the Wai‘anae Mountains but is now only known from the Natural Area Reserve at Ka‘ena Point. Chamaesyce kuwaleana is known to occur at Kaua‘ōpu‘u Peak, Pu‘u Kuwale and Pu‘u Kailio (Sharpe 1995).
References Cited
Hawaii Audubon Society. 1997. Hawaii's Birds.5. Hawaii Audubon Society. Honolulu, HI.
Juvik, S.P. and J.O. Juvik. 1998. Atlas of Hawaii. University of Hawaii Press.
Makua Implementation Team, Will Chee Planning Inc., and Hawaii Natural Heritage Program. 2003. Final Implementation Plan: Makua Military Reservation, Island of Oahu. Prepared for U. S. Army Garrison, Hawaii, Directorate of Public Works, under Contract No. DACA83-96-D-0007.
Oahu Nature Tours. 2004. Hawaii's Endangered Species: Endangered Oahu Elepaio. http://www.oahunaturetours.com/elepaio.html
Oki, D.S., and Brasher, A.M.D. 2003. Environmental Setting and the Effects of Natural and Human-Related Factors on Water Quality and Aquatic Biota: Oahu, Hawaii. Water-Resources Investigations Report 03-4156. U.S. Geological Survey. 98 pp. http://water.usgs.gov/pubs/wri/wri034156/
Sharpe, E. 1995. Recovery Plan for the Waianae Plant Cluster. U.S. Fish and Wildlife Service.
U.S. Fish and Wildlife Service (USFWS). 2001. Critical Habitat for the Oahu Elepaio. Fact Sheet. Portland, OR. http://pacific.fws.gov/news/2001/2001-79.htm
U.S. Fish and Wildlife Service (USFWS). 2003. What is the Difference Between Endangered and Threatened? USFWS Midwest Region. http://midwest.fws.gov/wolf/esa-status/e-vs-t.htm
U.S. Fish and Wildlife Service (USFWS). 2004a. Pacific Islands - Ecological Services: Threatened and Endangered Animal and Plant Species Listing for the Main Hawaiian Islands and the Northwestern Hawaiian Islands. http://pacificislands.fws.gov/wesa/plantsanimals.html
