Hawaiian Crow
Encyclopedia
The Hawaiian Crow or Alalā (Corvus hawaiiensis) is a species of bird
in the crow
family
, Corvidae
. It is about the size of the Carrion Crow
at 48–50 cm (18.9–19.7 in) 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. Some Native Hawaiians
consider the Hawaiian Crow an aumakua
(family god
).
. It inhabited dry
and mesic forests on the slopes of Mauna Loa
and Hualālai
at elevations of 300–2500 m (984.3–8,202.1 ft). Ōhia lehua (Metrosideros polymorpha
) and koa (Acacia koa) are important tree species in its habitat. Extensive understory
cover is necessary to protect the 'alala from predation by io
(Buteo solitarius), Hawaiian Hawk. Nesting sites receive 600–2500 mm (23.6–98.4 in) of annual rainfall. Fossil
remains indicate that it previously was relatively abundant on all the main islands, along with four other extinct crow species. The species is known for strong flying ability and resourcefulness, and the reasons for its extinction are not fully understood. It is thought that introduced diseases, such as Toxoplasma gondii
, avian malaria
(Plasmodium relictum), and fowlpox
, were probably a significant factor in the species' decline.
Hawaiian Crow is dominated by eggs
and nestlings, invertebrate
s, and fruit
; nectar, flower
s, and carrion
are minor components. Alalās will pry bark
off trees and eat the insect
s found underneath. Ieie (Freycinetia arborea
) vine
s are an important fruit source, although the birds are not normally seen in wet forests, where ieie density is highest.
's meow. It also makes a ca-wak sound, has a complex, burbling song, and makes a variety of other sounds as well.
by the IUCN Red List
. While some 78 individuals remain (as of July 2010) in two captive breeding
facilities operated by the San Diego Zoo
, attempts to reintroduce captive-bred birds into the wild have been hampered by predation by the Hawaiian Hawk
(Buteo solitarius), which is listed as Near Threatened
.
On April 16, 2009, The U.S. Fish and Wildlife Service announced a five year plan to spend more than $14 million to prevent the extinction of the Hawaiian Crow through protection of habitats
and management of threats
to the species.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the 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...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Corvidae
Corvidae
Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs and nutcrackers. The common English names used are corvids or the crow family , and there are over 120 species...
. It is about the size of the Carrion Crow
Carrion Crow
The Carrion Crow is a member of the passerine order of birds and the crow family which is native to western Europe and eastern Asia.-Taxonomy:...
at 48–50 cm (18.9–19.7 in) 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. Some Native Hawaiians
Native Hawaiians
Native Hawaiians refers to the indigenous Polynesian people of the Hawaiian Islands or their descendants. Native Hawaiians trace their ancestry back to the original Polynesian settlers of Hawaii.According to the U.S...
consider the Hawaiian Crow an aumakua
Aumakua
In Hawaiian mythology, an aumakua is a family god, often a deified ancestor. The Hawaiian plural of aumakua is nā aumākua , although in English the plural is usually aumakuas. Nā aumākua frequently manifested as animals such as sharks or owls. Nā aumākua were worshipped at localities where they...
(family god
Household deity
A household deity is a deity or spirit that protects the home, looking after the entire household or certain key members. It has been a common belief in pagan religions as well as in folklore across many parts of the world....
).
Distribution and habitat
The Hawaiian Crow is now extinct in the wild. Before this, the species was found only in the western and southeastern parts of the island of HawaiiHawaii (island)
The Island of Hawaii, also called the Big Island or Hawaii Island , is a volcanic island in the North Pacific Ocean...
. It inhabited dry
Hawaiian tropical dry forests
The Hawaiian tropical dry forests are a tropical dry broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of on the leeward side of the main islands and the summits of Niihau and Kahoolawe. These forests are either seasonal or sclerophyllous. Annual rainfall is less than and...
and mesic forests on the slopes of Mauna Loa
Mauna Loa
Mauna Loa is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean, and the largest on Earth in terms of volume and area covered. It is an active shield volcano, with a volume estimated at approximately , although its peak is about lower than that...
and Hualālai
Hualalai
Hualālai is a dormant shield volcano on the island of Hawaii in the Hawaiian Islands. It is the third-youngest and the third most active of the five volcanoes that form the island of Hawaii, following Kīlauea and the much larger Mauna Loa, and also the westernmost. Its peak is above sea...
at elevations of 300–2500 m (984.3–8,202.1 ft). Ōhia lehua (Metrosideros polymorpha
Metrosideros polymorpha
The ōhia lehua is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations, and much smaller when growing in boggy soils or on basalt...
) and koa (Acacia koa) are important tree species in its habitat. Extensive understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
cover is necessary to protect the 'alala from predation by io
Hawaiian Hawk
The 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), Hawaiian Hawk. Nesting sites receive 600–2500 mm (23.6–98.4 in) of annual rainfall. Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
remains indicate that it previously was relatively abundant on all the main islands, along with four other extinct crow species. The species is known for strong flying ability and resourcefulness, and the reasons for its extinction are not fully understood. It is thought that introduced diseases, such as Toxoplasma gondii
Toxoplasma gondii
Toxoplasma gondii is a species of parasitic protozoa in the genus Toxoplasma. The definitive host of T. gondii is the cat, but the parasite can be carried by many warm-blooded animals . Toxoplasmosis, the disease of which T...
, avian malaria
Avian malaria
Avian malaria is a parasitic disease of birds.-Etiology:Avian malaria is most notably caused by Plasmodium relictum, a protist that infects birds in tropical regions...
(Plasmodium relictum), and fowlpox
Fowlpox
Fowlpox is a worldwide disease of poultry caused by viruses of the family Poxviridae and the genus Avipoxvirus. The viruses causing fowlpox are distinct from one another but antigenically similar, possible hosts including chickens, turkeys, quail, canaries, pigeons, and many other species of...
, were probably a significant factor in the species' decline.
Diet
The varied diet of the omnivorousOmnivore
Omnivores are species that eat both plants and animals as their primary food source...
Hawaiian Crow is dominated by eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
and nestlings, invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, and fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
; nectar, flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s, and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
are minor components. Alalās will pry bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
off trees and eat the insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s found underneath. Ieie (Freycinetia arborea
Freycinetia arborea
The Ieie is a densely branched, brittle, woody climber in the screwpalm family, Pandanaceae that is endemic to the Pacific Islands. Ieie is found in moist forest on the Hawaiian, Marquesas, Austral, Society, and Cook Islands. It grows into the forest canopy, attaching itself to a host tree using...
) vine
Vine
A vine in the narrowest sense is the grapevine , but more generally it can refer to any plant with a growth habit of trailing or scandent, that is to say climbing, stems or runners...
s are an important fruit source, although the birds are not normally seen in wet forests, where ieie density is highest.
Voice
The Hawaiian Crow has a call described variously as a two-toned caw and as a screech with lower tones added, similar to a catCat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
's meow. It also makes a ca-wak sound, has a complex, burbling song, and makes a variety of other sounds as well.
Conservation status
The last two known wild individuals of this species disappeared in 2002; the species is now classified as Extinct in the WildExtinct in the Wild
Extinct in the Wild is a conservation status assigned to species or lower taxa, the only known living members of which are being kept in captivity or as a naturalized population outside its historic range.-Examples:...
by the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. While some 78 individuals remain (as of July 2010) in two captive breeding
Captive breeding
Captive breedingis the process of breeding animals in human controlled environments with restricted settings, such as wildlife reserves, zoos and other conservation facilities; sometimes the process is construed to include release of individual organisms to the wild, when there is sufficient...
facilities operated by the San Diego Zoo
San Diego Zoo
The San Diego Zoo in Balboa Park, San Diego, California, is one of the most progressive zoos in the world, with over 4,000 animals of more than 800 species...
, attempts to reintroduce captive-bred birds into the wild have been hampered by predation by the Hawaiian Hawk
Hawaiian Hawk
The 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), which is listed as Near Threatened
Near Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
.
On April 16, 2009, The U.S. Fish and Wildlife Service announced a five year plan to spend more than $14 million to prevent the extinction of the Hawaiian Crow through protection of habitats
Habitat conservation
Habitat conservation is a land management practice that seeks to conserve, protect and restore, habitat areas for wild plants and animals, especially conservation reliant species, and prevent their extinction, fragmentation or reduction in range...
and management of threats
Wildlife management
Wildlife management attempts to balance the needs of wildlife with the needs of people using the best available science. Wildlife management can include game keeping, wildlife conservation and pest control...
to the species.