Hawaiian Crow


Hawaiian Crow
Hawaiian Crow
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Corvidae
Genus: Corvus
Species: C. hawaiiensis
Binomial name
Corvus hawaiiensis
Peale, 1848
Range

The Hawaiian Crow or ʻAlalā (Corvus hawaiiensis) is a species of bird in the crow family, Corvidae. It is about the size of the Carrion Crow at 48–50 centimetres (19–20 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 ʻaumakua (family god).[2]

Contents

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 Hawaiʻi.[3] It inhabited dry and mesic forests on the slopes of Mauna Loa and Hualālai at elevations of 300–2,500 metres (980–8,200 ft). ʻŌhiʻa 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 ʻio (Buteo solitarius), Hawaiian Hawk. Nesting sites receive 600–2,500 millimetres (24–98 in) of annual rainfall.[4] 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.[3]

Behaviour

Diet

The varied diet of the omnivorous Hawaiian Crow is dominated by eggs and nestlings, invertebrates, and fruit; nectar, flowers, and carrion are minor components. ʻAlalās will pry bark off trees and eat the insects found underneath. ʻIeʻie (Freycinetia arborea) vines are an important fruit source, although the birds are not normally seen in wet forests, where ʻieʻie density is highest.[4]

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 cat'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;[5] the species is now classified as Extinct in the Wild by the IUCN Red List.[6] 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.[7]

Gallery

References

  1. ^ "Corvus hawaiiensis". IUCN Red List of Threatened Species. Version 2009.2. International Union for Conservation of Nature. 2008. http://www.iucnredlist.org/apps/redlist/details/146673. Retrieved 31 January 2010. 
  2. ^ Banko, Paul C.; Donna L. Ball; Winston E. Banko (2002). "Hawaiian Crow (Corvus hawaiiensis)". In A. Poole. The Birds of North America Online. Cornell Lab of Ornithology. http://bna.birds.cornell.edu/bna/species/648/articles/introduction. Retrieved 2009-03-20. 
  3. ^ a b "ʻAlalā or Hawaiian Crow" (PDF). Hawaii’s Comprehensive Wildlife Conservation Strategy. State of Hawaiʻi. 2005-10-01. http://www.state.hi.us/dlnr/dofaw/cwcs/files/NAAT%20final%20CWCS/Chapters/Terrestrial%20Fact%20Sheets/Forest%20Birds/alala%20NAAT%20final2%20!.pdf. Retrieved 2009-03-20. 
  4. ^ a b (PDF) Draft Revised Recovery Plan for the ʻAlalā (Corvus hawaiiensis). United States Fish and Wildlife Service. October 2003. http://www.fws.gov/pacific/ecoservices/endangered/recovery/documents/AlalaDraftRevisedRecoveryPlan.pdf. 
  5. ^ Walters, Mark Jerome (October–December 2006). "Do No Harm". Conservation Magazine (Society for Conservation Biology) 7 (4): 28–34. http://www.conbio.org/cip/article74har.cfm. 
  6. ^ IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. <http://www.iucnredlist.org>. Downloaded on 11 March 2010
  7. ^ THE ASSOCIATED PRESS (April 17, 2009). "$14M Effort Announced to Save Rare Hawaiian Bird". Science, Global edition (The New York Times). http://www.nytimes.com/aponline/2009/04/17/science/AP-Endangered-Bird-Hawaii.html?_r=1. Retrieved 2009-04-18.