Acacia koa, commonly known as koa, is a species of flowering tree in the family Fabaceae. It is endemic to the Hawaiian Islands, where it is the second most common tree. The highest populations are on Hawaiʻi, Maui and Oʻahu.
Located about 2300 miles (3680 km) from the nearest continental shore, the Hawaiian Islands are the most isolated group of islands on the planet. The plant and animal life of the Hawaiian archipelago is the result of early, very infrequent colonizations of arriving species and the slow evolution of those species—in isolation from the rest of the world's flora and fauna—over a period of at least 5 million years. As a consequence, Hawai'i is home to a large number of endemic species. The radiation of species described by Charles Darwin in the Galapagos Islands which was critical to the formulation of his theory of evolution is far exceeded in the more isolated Hawaiian Islands.
The Hawaiian tropical rainforests are a tropical moist broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of 6,700 km2 (2,600 sq mi) in the windward lowlands and montane regions of the islands. Coastal mesic forests are found at elevations from sea level to 300 m (980 ft). Mixed mesic forests occur at elevations of 750 to 1,250 m, while wet forests are found from 1,250 to 1,700 m. Moist bogs and shrublands exist on montane plateaus and depressions. For the 28 million years of existence of the Hawaiian Islands, they have been isolated from the rest of the world by vast stretches of the Pacific Ocean, and this isolation has resulted in the evolution of an incredible diversity of endemic species, including fungi, mosses, snails, birds, and other wildlife. In the lush, moist forests high in the mountains, trees are draped with vines, orchids, ferns, and mosses. This ecoregion includes one of the world's wettest places, the slopes of Mount Waiʻaleʻale, which average 373 in (9,500 mm) of rainfall per year.
Metrosideros polymorpha, the ʻōhiʻa lehua, is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaiʻi. It is a member of the diverse Metrosideros genus, which are widespread over the southwest Pacific. It is the state tree of Hawai‘i.
Acacia koaia, known as koaiʻa or koaiʻe in Hawaiian, is a species of acacia that is endemic to Hawaii. It is closely related to koa, and is sometimes considered to be the same species.
Pipturus albidus, known as māmaki in Hawaiian and known as Waimea pipturus in English, is a species of flowering plant in the nettle family, Urticaceae, that is endemic to Hawaiʻi. It inhabits coastal mesic, mixed mesic, and wet forests at elevations of 60–1,830 m (200–6,000 ft). Māmaki is a small tree that reaches a height of 9 m (30 ft) and a trunk diameter of 0.3 m (0.98 ft).
The Oʻahu ʻamakihi is a species of Hawaiian honeycreeper in the family Fringillidae. The male is rich yellow below, sharply contrasted with greenish upper parts. Females are duller and have two prominent wing-bars. It has a total length of approximately 4.5 inches (11 cm). It is endemic to the island of Oʻahu in Hawaiʻi, and is likely the only surviving honeycreeper endemic to the island.
The ʻakiapōlāʻau, pronounced ah-kee-ah-POH-LAH-OW, is a species of Hawaiian honeycreeper that is endemic to the island of Hawaii. Its natural habitats are dry and montane moist forests, and the only bird species on the island to occupy the woodpecker niche. The bird is 5.5 inches (14 cm) in length, and has an unusually curved beak-(a specialist species). The ʻakiapolaʻau is a pudgy bird which has a whitish bottom and tail, black legs, yellow chest, orangish head, black face mask and bill and gray black wings. The male's song is either a loud, short pit-er-ieu or a rapid warba-warba. Its various calls include an upslurred whistle, a short cheedle-ee warble, and a short sweet. Due to the recent disappearance of the Kauai nukupuʻu in the 1900s and the Maui nukupuʻu in the 1990s, leading to fears that they may be extinct, the ʻakiapōlāʻau may be the last of its genus. It is the only member of the subgenus Heterorhynchus, which has a woodpecker-like feeding habitat and exclusively preys on insects, in contrast to the nukupu'us, which were both insect-eaters and also hummingbird-like nectarivores.
The ʻanianiau is a species of Hawaiian honeycreeper that is endemic to upper elevation forests on the island of Kauai.
The ʻapapane is a small, crimson species of Hawaiian honeycreeper endemic to the Hawaiian Islands. They are the most abundant and widely distributed honeycreeper and are found on the islands of Hawaiʻi, Maui, Lānaʻi, Kauaʻi, Molokaʻi and Oʻahu.
Loxops is a Hawaiian honeycreeper genus in the finch family, Fringillidae. Most of them are commonly known as ʻakepa.
The Hawaiʻi creeper, Hawaii creeper or ʻalawī is a species of Hawaiian honeycreeper endemic to the Big Island of Hawaiʻi. Its natural habitats are dry forests and montane moist forests at elevations of 1,000–2,300 metres (3,300–7,500 ft). There are a total of 12,000 birds separated into three populations. A fourth population on the western part of the island probably represents migratory birds from one of the existing population. The Hawaiʻi creeper measures 4.5 inches (11 cm) and has drab green plumage. In 2017 the traditional Hawaiian name was rediscovered as 'alawi'.
Rhodacanthis, commonly known as the koa finches, is an extinct genus of Hawaiian honeycreeper in the subfamily Carduelinae of the family Fringillidae. All four species were endemic to Hawaii.
Hibiscadelphus giffardianus is a species of flowering plant in the mallow family Malvaceae that is endemic to the Big Island of Hawaii.
The Oʻahu nukupuʻu is an extinct species of nukupuʻu, a type of Hawaiian honeycreeper native to Oahu, which was similar to its cousins from the Islands of Kauaʻi and Maui. It is yellowish greyish with a long hooked beak to find insects. This bird is now extinct due to human activity.
Hawaiian tropical dry forests are a tropical dry broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of 6,600 km2 (2,500 sq mi) on the leeward side of the main islands and the summits of Niʻihau and Kahoʻolawe. These forests are either seasonal or sclerophyllous. Annual rainfall is less than 127 cm (50 in) and may be as low as 25 cm (9.8 in). The rainy season there lasts from November to March.
Hakalau Forest National Wildlife Refuge is a protected area on the Big Island of Hawaiʻi. It is one of two units, along with the Kona Forest National Wildlife Refuge that is managed as part of the Big Island National Wildlife Refuge Complex. Access to the Kona Forest is restricted since it contains several endangered species.
Udara blackburni, the Koa butterfly, is a butterfly in the family Lycaenidae that is endemic to Hawaiʻi. It is also known as Blackburn's butterfly, Blackburn's bluet, Hawaiian blue or green Hawaiian blue.
Koa wilt is a relatively new disease to Hawaii, discovered in 1980. Koa wilt is caused by a forma specialis of the fungus Fusarium oxysporum, which is now abundant in Hawaiian soils and infects the native Acacia koa tree, a once-dominant species in the canopy of Hawaiian forests. Fusarium oxysporum f.sp. koae is believed to have been brought into Hawaii on an ornamental acacia plant. Fusarium fungi clog the tree xylem, causing significant wilt and mortality among these beautiful and iconic Hawaiian trees.
Boehmeria grandis, commonly called ʻakolea, is a flowering species of the Urticaceae family that is endemic to the Hawaiian Islands. ʻakolea can be found in mesic to wet forests across Hawaiʻi along streams, on ridges, and valley floors. Multiple sources have cited observations in Makaua Gulch on Oʻahu.
