|Scientific Name:||Cryptotis nelsoni|
|Species Authority:||(Merriam, 1895)|
|Red List Category & Criteria:||Critically Endangered B1ab(i,ii,iii) ver 3.1|
|Assessor/s:||Woodman, N., Matson, J., Cuarón, A.D. & de Grammont, P.C.|
|Reviewer/s:||Amori, G. & Chiozza, F.|
Listed as Critically Endangered because its extent of occurrence is less than 100 km², it is known from only one location, and there is continuing decline in the extent and quality of its habitat.
|Range Description:||Until recently, this species was known only from the type locality; which is on the western slope of the extinct Volcán San Martín Tuxtla in Veracruz, Mexico (Hutterer 2005). It has been recorded from 1,463 m up to the summit of the volcano at 1,650 m asl (Goldman 1951). Recently, it was found at three additional localities in the vicinity of the type locality (Cervantes and Guevara 2009). These localities lie on the south face of the volcano and just to the north west of the nearby Catemaco Lake (Cervantes and Guevara 2009). It has been hypothesized that this shrew probably occurs in suitable habitats throughout that Sierra (Choate1970). However, a recent study on the mammalian diversity of Sierra de Santa Martha,
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||It was considered common when collected by Goldman (1951). One adult male, one male juvenile, and one female adult have been recently found by Cervantes and colleagues (Cervantes and Guevara 2009).|
|Habitat and Ecology:||
The habitat reported by Merriam (1895) for the holotype and paratypes was evergreen tropical forest, represented by well-conserved vegetation that consisted of areas covered by layers of volcanic sand and ashes and trees of large size (Choate 1970, Goldman1951). The lower section of its range, from 1,460 to 1,525 m asl, is within dense primary forest; above this elevation it is montane grassland. The vegetation where the recently discovered specimens were obtained was cloud forest. In one of the three localities sampled, at 1,500m, the trees of the canopy were unusually low (Cervantes and Guevara 2009). It is an insectivorous species, feeding exclusively on insects.
|Major Threat(s):||The habitat of C. nelsoni is gradually changing or disappearing due to the use of land within the Los Tuxtlas Biosphere Reserve. The activities within the reserve frequently involve logging, cattle grazing, induced fires, and crops (Cervantes and Guevara 2009) . In the area of the type locality, deforestation is as much as 90% and the annual deforestation rate is 6.2% (Dirzo and Garcia 1992).|
|Conservation Actions:||Part of the distribution is included in the Los Tuxtlas Biosphere Reserve and Los Tuxtlas Biological Station. According to Cervantes and Guevara (2009), a specific conservation action plan is needed in order to buffer and eventually halt alterations of the habitat and protect the integrity of the populations of this species.|
Carraway, L. N. 2007. Shrews (Eulypotyphla: Soricidae) of Mexico. Western North American Naturalist 3.
Cervantes, F. A., and Guevara, L. 2009. Rediscovery of the critically endangered Nelson’s small-eared shrew (Cryptotis nelsoni), endemic to Volcán San Martín, Eastern México. Mammalian Biology.
Choate, J. R. 1970. Systematics and zoogeography of the Middle American shrews of the genus Cryptotis. University of Kansas Publications, Museum of Natural History 19: 195-317.
Dirzo, R. and Garcia, M. C. 1992. Rates of deforestation in Los Tuxtlas, a neotropical area in Veracruz, Mexico. Conservation Biology 6(1): 84-90.
Goldman, E. A. 1951. Biological investigations in Mexico. Smithsonian Miscellaneous Collections 115: 1-476.
Gonzalez Christen, A. 2008. La diversidad alfa, beta y gamma de la mastofauna en la Sierra de Santa Marta, Veracruz, Mexico. In: Lorenzo, C., Espinoza, E., and Ortega, J. (eds), Avances en el Estudio de los Mamiferos de Mexico, Asociacion Mexicana de Mastozoologia, San Cristobal de las Casas, Chiapas, Mexico.
Hutterer, R. 2005. Order Soricomorpha. In: D. E. Wilson and D. M. Reeder (eds), Mammal Species of the World, pp. 220-311. Johns Hopkins University Press, Baltimore, Maryland, USA.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.4). Available at: http://www.iucnredlist.org. (Accessed: 27 October 2010).
Merriam , C.H. 1895. Revision of the shrews of the American genera Blarina and Notiosorex. NorthAm. Fauna 10: 1-34.
Nowak, R. M. 1999. Walker's Mammals of the World. The Johns Hopkins University Press, Baltimore, USA and London, UK.
|Citation:||Woodman, N., Matson, J., Cuarón, A.D. & de Grammont, P.C. 2010. Cryptotis nelsoni. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 23 May 2013.|
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