Oryzomys nelsoni


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Oryzomys nelsoni
Species Authority: Merriam, 1898
Common Name(s):
English Nelson's Rice Rat, Tres Marias Island Rice Rat

Assessment Information [top]

Red List Category & Criteria: Extinct ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Timm, R., Álvarez-Castañeda, S.T. & Lacher, T.
Reviewer(s): McKnight, M. (Global Mammal Assessment Team) & Amori, G. (Small Nonvolant Mammal Red List Authority)
This species is listed as Extinct as it has not been found in recent years despite surveys. It was only known from a few records in the marsh areas of the high central part of Maria Madre Island. It was last recorded in 1897.
1996 Extinct
1994 Extinct? (Groombridge 1994)
1990 Extinct? (IUCN 1990)

Geographic Range [top]

Range Description: This species is known only from the type locality in Nayarit State, México: María Madre Island (Musser and Carleton 2005).
Regionally extinct:
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This species is known only by the four specimens of the type series. After extensive trapping that produced only a few specimens, O. nelsoni was believed to be rare (Nelson 1899 in Alvarez-Castañeda and Mendez 2003). More recent trapping in the type locality revealed only Rattus rattus (Wilson 1991 in Alvarez-Castañeda and Mendez 2003), and this species is currently considered extinct (IUCN, 2006).

Habitat and Ecology [top]

Habitat and Ecology: This species occurred in damp areas near springs and close to the summit of Maria Madre. This habitat has abundant herbaceous vegetation in the undergrowth (Alvarez-Castañeda and Mendez 2003).

Nelson’s rice rat may have fed on seeds, fruits, weeds, and occasionally small fish and invertebrates (Alvarez-Castañeda and Mendez 2003).
Systems: Terrestrial

Threats [top]

Major Threat(s): The extinction of the species may have been caused by Rattus rattus (Wilson 1991 in Alvarez-Castañeda and Mendez 2003).

Conservation Actions [top]

Conservation Actions: None.

Bibliography [top]

Alvarez-Castaneda, S. T. and Mendez, L. 2003. Oryzomys nelsoni. Mammalian Species 735: 1-2.

Musser, G. G. and Carleton, M. D. 2005. Superfamily Muroidea. In: D. E. Wilson and D. A. Reeder (eds), Mammal Species of the World: a geographic and taxonomic reference, pp. 894-1531. The John Hopkins University Press, Baltimore, USA.

Citation: Timm, R., Álvarez-Castañeda, S.T. & Lacher, T. 2008. Oryzomys nelsoni. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 26 March 2015.
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