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Corvus hawaiiensis
– Extinct in the Wild
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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AVES
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Order:
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PASSERIFORMES
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Family:
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CORVIDAE
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Scientific Name:
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Corvus hawaiiensis
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Species Authority:
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Peale, 1848
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Common Name/s:
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HAWAIIAN CROW (Eng)
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Assessment Information
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Red List Category & Criteria:
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EW ver 3.1 (2001)
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Year Assessed:
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2004
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Assessor/s:
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BirdLife International
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Evaluator/s:
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Stattersfield, A., Benstead, P., Stuart, T. & Butchart, S. (BirdLife International Red List Authority)
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Justification:
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The last two known wild individuals of this species disappeared in 2002, so the species is now classified as Extinct in the Wild. Some individuals remain in captive breeding facilities and a reintroduction plan is being developed.
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History:
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| 1988 | - | Threatened (Collar and Andrew 1988) |
| 1994 | - | Critically Endangered (Collar, Crosby and Stattersfield 1994) |
| 2000 | - | Critically Endangered (BirdLife International 2000) |
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Geographic Range
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Range Description:
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Corvus hawaiiensis was endemic to Hawai`i in the Hawaiian Islands (USA), where the last individuals were found only in the Kona Forest Unit of Hakalau National Wildlife Refuge. In 1992, there were only 11 or 12 birds5,6, which had declined to three in October 19996, and the last two individuals were last seen in June 2002: they did not return to their traditional nesting site in 2003 and have not been seen since. The species persists in captive breeding facilities, with development of a reintroduction program in progress7. Captive breeding started in the 1970s and, by 1998, 24 birds had been released but, during 1997-1998, 18 died and the rest were recaptured to protect them and preserve genetic diversity1,2,5.
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Countries:
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Regionally extinct:
United States (Hawaiian Is.)
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Habitat and Ecology
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Habitat and Ecology:
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It inhabited wet `ohi`a-koa forest, scrub and rangelands but it became confined to high mountain forest. It is omnivorous, but primarily feeds on the fruit of native understory plants5,6.
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System:
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Terrestrial; Freshwater; Marine
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Threats
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Threats:
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It has suffered from extensive habitat alteration, particularly reduction of understory food-plants as a result of the activities of feral ungulates, logging, agriculture and the loss of pollinators and dispersers6. The impact of collecting and shooting has probably also been substantial, even in recent decades. Other documented threats include predation by introduced rats, the small Indian mongoose Herpestes auropunctatus and the native Hawaiian Hawk Buteo solitarius (classified as Near Threatened), and avian malaria and pox carried by introduced mosquitoes5. Captive-reared birds have also suffered from disease, with at least one dying from bacterial infection, and diseases may have made others more vulnerable to predation1,5.
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Conservation Actions
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Conservation Actions:
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Conservation measures underway:
Captive-raised individuals were released into managed habitat and monitored3,4, but this was stopped in September 1998, following the death of three birds in as many days5). Introduced mammalian predators are trapped in the Kona Forest Unit. Translocation of B. solitarius failed because the birds homed back from over 32 km1. An environmental assessment is in preparation, other potential release-sites have been investigated, and suggestions are under consultation6.
Conservation measures proposed:
Develop a reintroduction plan. Restore and manage a significant proportion of remaining habitat within and around the Kona Forest Unit. Manage cattle-ranches to preserve critical habitats. Expand the trapping of introduced predators and the protection of nest-sites. Deal creatively with the problem posed by B. solitarius1,5,6.
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