Endemism in the Hawaiian Islands
Encyclopedia
Located some 2,400 miles (4,000 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 70 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 relatively short time that the existing main islands of the archipelago have been above the surface of the ocean (less than 10 million years) is only a fraction of time span over which biological colonization and evolution have occurred in the archipelago. High, volcanic islands have existed in the Pacific far longer, extending in a chain to the northwest; these once mountainous islands are now reduced to submerged banks and coral atoll
s. Midway Atoll
, for example, formed as a volcanic island some 28 million years ago. Kure Atoll
, a little further to the northwest, is near the Darwin Point—defined as waters of a temperature that allows coral reef development to just keep up with isostatic
sinking. And extending back in time before Kure, an even older chain of islands spreads northward nearly to the Aleutian Islands; these former islands, all north of the Darwin Point, are now completely submerged as the Emperor Seamounts.
The islands are well known for the environmental diversity that occurs on high mountains within a trade wind
s field. On a single island, the climate can differ around the coast from dry tropical (< 20 in or 500 mm annual rainfall) to wet tropical; and up the slopes from tropical rainforest (> 200 in or 5000 mm per year) through a temperate climate into alpine conditions of cold and dry climate. The rainy climate impacts soil development, which largely determines ground permeability, which effects the distribution of streams, wetlands, and wet places.
The distance and remoteness of the Hawaiian archipelago is a biological filter. Seeds or spores attached to a lost migrating bird's feather or an insect falling out of the high winds found a place to survive in the islands and whatever else was needed to reproduce. The narrowing of the gene pool meant that at the very beginning, the population of a colonizing species was a bit different from that of the remove, contributing population.
and later by European
s, has had a significant impact. Both the Polynesians and Europeans cleared native forests and introduced non-indigenous species for agriculture (or by accident), driving many endemic species to extinction. Fossil finds in cave
s, lava tube
s, and sand dunes have revealed an avifauna that once had an endemic eagle
, two raven-size crow
s, several bird-eating owl
s, and giant ducks known as moa-nalos.
Today, many of the remaining endemic species of plants and animals in the Hawaiian Islands are considered endangered, and some critically so. Plant species are particularly at risk: out of a total of 2,690 plant species, 946 are non-indigenous with 800 of the native species listed as endangered. http://www.news.cornell.edu/releases/Jan99/species_costs.html
Hawaiian Islands
The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...
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 70 million years. As a consequence, Hawai'i is home to a large number of endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
species. The radiation of species described by Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
in the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
which was critical to the formulation of his Theory of Evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
is far exceeded in the more isolated Hawaiian Islands.
The relatively short time that the existing main islands of the archipelago have been above the surface of the ocean (less than 10 million years) is only a fraction of time span over which biological colonization and evolution have occurred in the archipelago. High, volcanic islands have existed in the Pacific far longer, extending in a chain to the northwest; these once mountainous islands are now reduced to submerged banks and coral atoll
Atoll
An atoll is a coral island that encircles a lagoon partially or completely.- Usage :The word atoll comes from the Dhivehi word atholhu OED...
s. Midway Atoll
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...
, for example, formed as a volcanic island some 28 million years ago. Kure Atoll
Kure Atoll
Kure Atoll or Ocean Island is an atoll in the Pacific Ocean beyond Midway Atoll in the Northwestern Hawaiian Islands at . The only land of significant size is called Green Island and is habitat for hundreds of thousands of seabirds...
, a little further to the northwest, is near the Darwin Point—defined as waters of a temperature that allows coral reef development to just keep up with isostatic
Isostasy
Isostasy is a term used in geology to refer to the state of gravitational equilibrium between the earth's lithosphere and asthenosphere such that the tectonic plates "float" at an elevation which depends on their thickness and density. This concept is invoked to explain how different topographic...
sinking. And extending back in time before Kure, an even older chain of islands spreads northward nearly to the Aleutian Islands; these former islands, all north of the Darwin Point, are now completely submerged as the Emperor Seamounts.
The islands are well known for the environmental diversity that occurs on high mountains within a trade wind
Trade wind
The trade winds are the prevailing pattern of easterly surface winds found in the tropics, within the lower portion of the Earth's atmosphere, in the lower section of the troposphere near the Earth's equator...
s field. On a single island, the climate can differ around the coast from dry tropical (< 20 in or 500 mm annual rainfall) to wet tropical; and up the slopes from tropical rainforest (> 200 in or 5000 mm per year) through a temperate climate into alpine conditions of cold and dry climate. The rainy climate impacts soil development, which largely determines ground permeability, which effects the distribution of streams, wetlands, and wet places.
The distance and remoteness of the Hawaiian archipelago is a biological filter. Seeds or spores attached to a lost migrating bird's feather or an insect falling out of the high winds found a place to survive in the islands and whatever else was needed to reproduce. The narrowing of the gene pool meant that at the very beginning, the population of a colonizing species was a bit different from that of the remove, contributing population.
Human arrival
Human contact, first by PolynesiansPolynesians
The Polynesian peoples is a grouping of various ethnic groups that speak Polynesian languages, a branch of the Oceanic languages within the Austronesian languages, and inhabit Polynesia. They number approximately 1,500,000 people...
and later by European
European ethnic groups
The ethnic groups in Europe are the various ethnic groups that reside in the nations of Europe. European ethnology is the field of anthropology focusing on Europe....
s, has had a significant impact. Both the Polynesians and Europeans cleared native forests and introduced non-indigenous species for agriculture (or by accident), driving many endemic species to extinction. Fossil finds in cave
Cave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
s, lava tube
Lava tube
Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow, expelled by a volcano during an eruption. They can be actively draining lava from a source, or can be extinct, meaning the lava flow has ceased and the rock has cooled and left a long, cave-like...
s, and sand dunes have revealed an avifauna that once had an endemic eagle
Eagle
Eagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...
, two raven-size crow
Crow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
s, several bird-eating owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s, and giant ducks known as moa-nalos.
Today, many of the remaining endemic species of plants and animals in the Hawaiian Islands are considered endangered, and some critically so. Plant species are particularly at risk: out of a total of 2,690 plant species, 946 are non-indigenous with 800 of the native species listed as endangered. http://www.news.cornell.edu/releases/Jan99/species_costs.html
A list of endemic species of Hawai‘i
- Note that, simply because of the relatively small area involved, many Hawaiian species are considered threatened even when at their normal population levels.
- Hawaiian Hoary BatHawaiian Hoary batThe Hawaiian Hoary bat or Ōpeapea is a subspecies of the Hoary bat that is endemic to the Hawaiian Islands...
(Lasiurus cinereus semotus) - endangered - Hawaiian DuckHawaiian DuckThe Hawaiian Duck is a species of bird in the family Anatidae. It is endemic to the large islands of Hawaii. Some authorities treat it as an island subspecies of the Mallard, based on their capacity to produce fertile hybrids, but it appears well distinct and capability of hybridization is...
(Anas wyvilliana) - endangered - Laysan DuckLaysan DuckThe Laysan Duck , also known as the Laysan Teal because of its small size, is an endangered dabbling duck endemic to the Hawaiian Islands...
(Anas laysanensis) - critically endangered - NeneHawaiian GooseThe Nene, also known as Nēnē and Hawaiian Goose, is a species of goose endemic to the Hawaiian Islands. The official bird of the state of Hawaii, the Nene is exclusively found in the wild on the islands of Maui, Kauai and Hawaii...
(Branta sandvicensis) - vulnerable - Hawaiian PetrelHawaiian PetrelThe Hawaiian Petrel or Uau is a large, dark grey-brown and white petrel that is endemic to Hawaii.-Distribution:...
(Pterodroma sandwichensis) - vulnerable - Newell's ShearwaterNewell's ShearwaterNewell's Shearwater or Hawaiian Shearwater is a seabird belonging to the genus Puffinus in the family Procellariidae. It belongs to a confusing group of shearwaters which are difficult to identify and whose classification is controversial...
(Puffinus newelli) - endangered - Hawaiian HawkHawaiian HawkThe Hawaiian Hawk or Io, Buteo solitarius, is a raptor of the Buteo genus endemic to Hawaii. Buteos tend to be easily recognized by their bulky bodies relative to their overall length and wingspan. The Io is the only hawk that is native to Hawaii, and fossil evidence indicates that it inhabited...
(Buteo solitarius) - near threatened - Laysan RailLaysan RailThe Laysan Rail or Laysan Crake was a tiny inhabitant of the Northwest Hawaiian Island of Laysan. This small island was and still is an important seabird colony, and sustained a number of endemic species, including the rail. It became extinct due to habitat loss by domestic rabbits, and ultimately...
(Porzana palmeri) - extinct - Hawaiian RailHawaiian RailThe Hawaiian Rail , Hawaiian Spotted Rail, or Hawaiian Crake was a somewhat enigmatic species of diminutive rail that lived on Big Island of Hawaii, but is now extinct. It was a flightless bird that was apparently found in shrubland and secondary growth on abandoned fields and in times of danger...
(Porzana sandwichensis) - extinct - Hawaiian MoorhenCommon MoorhenThe Common Moorhen is a bird in the Rallidae family with an almost worldwide distribution. The North and South American Committees of the AOU and the IOC have voted on or before July 2011 to split the American forms into a new species Common Gallinule, however, no other committee has voted to...
(Gallinula chloropus sanvicensis) - Hawaiian CootHawaiian CootThe Hawaiian Coot or alae keokeo is a species of bird in the rail family, Rallidae, that is endemic to Hawaii....
(Fulica alai) - vulnerable - Hawaiian Stilt (Himantopus himantopus knudseni)
- Hawaiian Black NoddyBlack NoddyThe Black Noddy or White-capped Noddy is a seabird from the tern family. It resembles the closely related Brown or Common Noddy , but is smaller with darker plumage, a whiter cap, a longer, straighter beak and shorter tail...
(Anous minutus melanogenys) - PueoPueoThe Pueo is a subspecies of Short-eared owl that is endemic to Hawaii. The pueo is one of the various nā aumākua in Hawaiian culture....
(Asio flammeus sandwichensis) - Kaua'i O'o (Moho braccatus) - extinct
- Oʻahu ʻŌʻō (Moho apicalis) - extinct
- Molokaʻi ʻŌʻō (Moho bishopi) - extinct
- Hawai'i ʻŌʻō (Moho nobilis) - extinct
- KioeaKioeaThe Kioea was a Hawaiian bird that became extinct around 1859. The kioea was in decline even before the discovery of Hawaii by Europeans. Even native Hawaiians are seemingly unfamiliar with this bird. The feathers of the kioea were not used in Hawaiian featherwork, nor is it mentioned in any...
(Chaetoptila angustipluma) - extinct - Kama'O (Myadestes myadestinus) - extinct
- 'Amaui'AmauiThe Oahu Thrush or ʻĀmaui, Myadestes woahensis, was a bird in the genus Myadestes . Endemic to the island of Oahu, it was the first of its genus to go extinct, ca. 1850....
(Myadestes woahensis) - extinct - Oloma'O (Myadestes lanaiensis) - critically endangered/extinct
- Oma'O (Myadestes obscurus) - vulnerable
- PuaiohiPuaiohiThe Puaiohi or Small Kauai Thrush The Puaiohi or Small Kauai Thrush The Puaiohi or Small Kauai Thrush ((Myadestes palmeri) is a rare species of songbird in the thrush family, Turdidae, that is endemic to the Hawaiian island of Kauai. It is closely related to the other four endemic Hawaiian...
(Myadestes palmeri) - critically endangered - MillerbirdMillerbirdThe Millerbird is a species of Old World warbler in the family Acrocephalidae. It had two subspecies, A. f. kingi and A f. familiaris. The latter, the Laysan Millerbird, became extinct sometime between 1916 and 1923. The former, the critically endangered Nihoa Millerbird, remains the only race...
(Acrocephalus familiaris) - critically endangered - Elepaio (Chasiempis sp.) - vulnerable
- Hawaiian CrowHawaiian CrowThe Hawaiian Crow or Alalā is a species of bird in the crow family, Corvidae. It is about the size of the Carrion Crow at in length, but with more rounded wings and a much thicker bill. It has soft, brownish-black plumage and long, bristly throat feathers; the feet, legs and bill are black...
(Corvus hawaiiensis) - extinct in wild - Laysan FinchLaysan FinchThe Laysan Finch is a species of finch in the Hawaiian honeycreeper subfamily, Drepanidinae, that is endemic to the Northwestern Hawaiian Islands. It is one of four remaining finch-billed Hawaiian honeycreepers, and is closely related to the smaller Nihoa Finch. The Laysan Finch is named for...
(Telespiza cantans) - vulnerable - Nihoa FinchNihoa FinchThe Nihoa Finch is one of the two endemic bird species of the tiny Hawaiian island Nihoa, the other being the Nihoa Millerbird. When it was classified in 1917, scientists thought that it would be the last endemic species named. This was later found untrue. The island's population is 1000-3000 birds...
(Telespiza ultima) - critically endangered - Lesser Koa FinchLesser Koa FinchThe Lesser Koa Finch is an extinct species of finch in the Hawaiian honeycreeper subfamily, Drepanididae.-Description:...
(Rhodacanthus flaviceps) - extinct - Greater Koa FinchGreater Koa FinchThe Greater Koa Finch was a species of finch in the Fringillidae family. It was found only in the Hawaiian Islands. It has been extinct since the late 19th century.- Description :...
(Rhodacanthus palmeri) - extinct - Maui ParrotbillMaui ParrotbillThe Maui Parrotbill or kiwikiu is a species of finch in the Hawaiian honeycreeper subfamily, Drepanidinae, that is endemic to Maui in Hawaii. It can only be found in of mesic and wet forests at on the windward slopes of Haleakalā. This species is critically endangered, with an estimated...
(Pseudonestor xanthophrys) - critically endangered - [[ʻŌʻū]] (Psittirostra psittacea) - critically endangered/extinct
- PalilaPalilaThe Palila is a critically endangered finch-billed species of Hawaiian honeycreeper. It has a golden-yellow head and breast, with a light belly, gray back, and greenish wings and tail...
(Loxioides bailleui) - critically endangered - Lana'i Hookbill (Dysmorodrepanis munroi) - extinct
- Kona GrosbeakKona GrosbeakThe Kona Grosbeak is an extinct species of finch in the Hawaiian honeycreeper subfamily, Drepanidinae. The Kona Grosbeak was endemic to naio forests on ʻaʻā lava flows at elevations of near the Kona District on the island of Hawaii...
(Chlroidops kona) - extinct - Common Amakihi (Hemignathus virens) - least concern
- O'ahu 'Amakihi (Hemignathus flavus) - vulnerable
- Kaua'i 'Amakihi (Hemignathus kauaiensis) - vulnerable
- Greater 'Amakihi (Hemignathus sagittirostris) - extinct
- Nukupu'u (Hemignathus lucidus) - critically endangered/extinct
- 'Akiapola'au (Hemignathus munroi) - endangered
- 'Anianiau (Magumma parva) - vulnerable
- Hawai'i 'Akialoa (Akialoa obscura) - extinct
- Kaua'i 'Akialoa (Akialoa stejnegeri) - extinct
- Maui Nui 'AkialoaMaui Nui 'AkialoaThe Maui Nui 'Akialoa or Lana'i 'Akialoa is a species of finch in the Fringillidae family. It was endemic to the island of Lanai, Hawaii in modern times, but seems to have occurred on all major islands of former Maui Nui before human settlement. The Maui Nui Akialoa was one of the birds that made...
(Akialoa lanaiensis)- extinct - Oahu 'AkialoaOahu 'AkialoaThe Oahu Akialoa was a species of finch in the Fringillidae family. The Oahu Akialoa was a species of Akialoa, or long-billed insectivorous bird that was that was found in the high elevation forest. It was a dull colored species, dull green on the belly, bright green on tail on rump and tail, dark...
(Akialoa ellisiana) - extinct - 'Akeke'e (Loxops caeruleirostris) - critically endangered
- 'Akepa (Loxops coccineus) - endangered
- 'Akikiki (Oreomystis bairdi) - critically endangered
- Hawai'i Creeper (Oreomystis mana) - endangered
- Molokai CreeperMolokai CreeperParoreomyza flammea, commonly known as the Kākāwahie or Molokai Creeper, was a species of finch in the Hawaiian honeycreeper subfamily, Drepanidinae. It is extinct, but formerly occurred on the Hawaiian island of Molokai in Hawaii. It was long with clawed toes. This bird had the appearance of a...
(Paroreomyza flammea) - extinct - O'ahu 'Alauahio (Paroreomyza maculata) - critically endangered
- Maui Nui ʻAlauahio (Paroreomyza montana) - endangered
- 'Akohekohe (Palmeria dolei) - critically endangered
- Po'ouli (Melamprosops phaeosoma) - critically endangered
- 'Ula-'ai-Hawane (Ciridops anna) - extinct
- Hawai'i MamoHawai'i MamoThe Hawai'i Mamo was a species of finch in the Hawaiian honeycreeper subfamily, Drepanididae. It was endemic to Hawaii. It became extinct due to habitat loss and overcollecting.-Description:...
(Drepanis pacifica) - extinct - Black MamoBlack MamoThe Black Mamo is an extinct bird species once endemic to the island of Molokai, although there is fossil evidence of it having lived on Maui....
(Drepanis funerea) - extinct - 'Apapane (Himantione sanguinea) - near threatened
- Snail-eating caterpillarHyposmocoma molluscivoraHyposmocoma molluscivora is a Hawaiian moth whose larvae are predators, capturing snails in their silk, much like a hunting spider's web, and then crawling inside the snail's shell to eat it alive...
(Hyposmocoma molluscivora) - Happy face spider (Theridion grallator)
- Hawaiian Tree snails - endangered*
- Yellow hibiscusHawaiian hibiscusHawaiian hibiscus are the seven known species of hibiscus regarded as native to Hawaii. Although tourists regularly associate the hibiscus flower with their experiences visiting the US state of Hawaii, and the plant family Malvaceae includes a relatively large number of species that are native to...
(Hibiscus brackenridgei) - endangered - Loulu – (PritchardiaPritchardiaThe genus Pritchardia consists of between 24-40 species of fan palms found on tropical Pacific Ocean islands in Fiji, Samoa, Tonga, Tuamotus, and Hawaii. The generic name honours William Thomas Pritchard , a British consul at Fiji.-Description:These palms vary in height, ranging from...
fan palms)
See also
- Endemic birds of HawaiiEndemic birds of HawaiiThis article is one of a series providing information about endemism among birds in the World's various zoogeographic zones. For an overview of this subject see Endemism in birds....
- List of Hawaii birds
- Hawaiian lobelioidsHawaiian lobelioidsThe Hawaiian lobelioids are a group of flowering plants in the bellflower family, Campanulaceae, all of which are endemic to the Hawaiian Islands. This is the largest plant radiation in the Hawaiian Islands, and indeed the largest on any island archipelago, with over 125 species...
- List of extinct animals of the Hawaiian Islands
- Environment of HawaiiEnvironment of HawaiiThe majority of environmental concerns affecting Hawaii today are related to pressures from increasing human and animal population in the limited separation space of the islands.-Flora and fauna:...
External links
- Flora of the Hawaiian Islands from the Smithsonian Institution