|Scientific Name:||Aaadonta constricta ssp. komakanensis|
|Species Authority:||Solem, 1976|
|Red List Category & Criteria:||Critically Endangered (Possibly Extinct) B1ab(i,ii,iii)+2ab(i,ii,iii) ver 3.1|
|Reviewer(s):||Barker, G., Seddon, M. & Pippard, H.|
This is a minute ground-dwelling snail for which no shells (live or dead) have been found in recent years, despite recent extensive surveys of its island habitat of Koror. The subspecies was previously known only from Koror, where it was collected at a single locality in 1936 by Y. Kondo. The species is listed as Critically Endangered (Possibly Extinct) due to a very small and declining extent of occurrence and area of occupancy, the species being found in a single location, and a decline in availability and quality of its habitat. Additional surveys of the island are needed to verify whether the subspecies is in fact Extinct, but based on extinctions of endodontids elsewhere in the Pacific, as well as other extirpations of endemic land snails on Koror, optimism is low.
This is a minute ground-dwelling snail that was historically known from the island of Koror (Oreor), where it was collected at a single locality in 1936 by Y. Kondo (Solem 1976). The historical geographic range was less than 20km2, and probably only approximately 7km2 (R. Rundell pers.comm. 2011). The species was probably historically more abundant prior to its collection at only a single locality in 1936.
|Estimated area of occupancy (AOO) - km2:||0|
|Continuing decline in area of occupancy (AOO):||Yes|
|Estimated extent of occurrence (EOO) - km2:||7|
|Continuing decline in extent of occurrence (EOO):||Yes|
|Number of Locations:||1|
|Lower elevation limit (metres):||1|
|Upper elevation limit (metres):||200|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Aaadonta constricta komakanensis is a minute ground-dwelling snail for which no shells (live or dead) have been found in recent years, despite surveys of its island habitat of Oreor (“Koror”) in 2003, 2005 and 2007 (R.J. Rundell 2007 unpublished data; Rundell, 2005, 2010). The subspecies was previously known only from Oreor, where it was collected at a single locality in 1936 by Y. Kondo (Solem 1976: 478).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||This is a ground-dwelling snail recorded from moist lowland forest.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||This species is not utilized.|
A. constricta komakanensis is (or was) threatened by destruction and modification of native lowland forest. Therefore it is not surprising that the species has probably been extirpated from the highly modified and deforested island of Koror. Disruption of the ground, rocks and leaf litter may be of particular significance to this and other endodontid species. Endodontoid land snails are among the most threatened land snails on Pacific Islands in the few places where they still exist (Solem 1983).
|Conservation Actions:||This species is not protected. Field work to define the current distribution of this species, as well as research on its population status and trends, is required. Identification of priority sites for species conservation (e.g. key biodiversity areas that include threatened land snails) and reducing the impacts of human activities, especially on the small islands, is also urgently needed. The Palau Conservation Society has been supportive of recent land snail survey work in Palau.|
Colin, PL. 2009. Marine Environments of Palau. Indo-Pacific Press, San Diego.
Cowie, RH, Allison, A, Howarth, FG, Samuelson, GA, Evenhuis, NL. 1996. Impacts of the Palau Compact Road: Survey of the non-marine fauna of the Island of Babeldaob. Will Chee Planning, Honolulu.
Crombie, R.I. and Pregill, G.K. 1999. A checklist of the herpetofauna of the Palau Islands (Republic of Belau), Oceania. Herpetological Monographs 13: 29-80.
Hinz, E. 1995. Pacific Island Battlegrounds of World War II: Then and Now. The Bess Press, Honolulu.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.2). Available at: http://www.iucnredlist.org. (Accessed: 17 October 2012).
Motteler, LS. 2006. Pacific Island Names. Bishop Museum Press, Honolulu.
Rundell, RJ. 2005. The land snails of Belau: Survey of the 16 states.
Rundell, RJ. 2008. Cryptic diversity, molecular phylogeny and biogeography of the rock- and leaf litter-dwelling land snails of Belau (Republic of Palau, Oceania). Philosophical Transactions of the Royal Society of London B 363: 3401-3412.
Rundell, RJ. 2010. Diversity and conservation of the land snail fauna of the western Pacific islands of Belau (Republic of Palau, Oceania). American Malacological Bulletin 28: 81-90.
Smith, B.D. 1993. Working list of the terrestrial gastropods of Palau, Caroline Islands. Working List No. 4. Dickinson Memorial Mollusc Collection, Marine Laboratory, University of Guam.
Solem, A. 1976. Endodontoid land snails from Pacific islands (Mollusca: Pulmonata: Sigmurethra). Part I. Family Endodontidae. Field Museum of Natural History, Chicago.
Solem, A. 1983. Endodontoid land snails from Pacific islands (Mollusca: Pulmonata: Sigmurethra). Part II. Families Punctidae and Charopidae. Zoogeography. Field Museum of Natural History, Chicago.
|Citation:||Rundell, R.J. 2012. Aaadonta constricta ssp. komakanensis. The IUCN Red List of Threatened Species 2012: e.T198785A2534908. . Downloaded on 27 June 2016.|
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