Nesoryzomys indefessus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Rodentia Cricetidae

Scientific Name: Nesoryzomys indefessus
Species Authority: (Thomas, 1899)
Common Name(s):
English Indefatigable Galapagos Mouse
Taxonomic Notes: This species previously has been considered a synonymous with N. narboroughi (see Musser and Carleton 1993). Recent evidence suggests that the two should be treated as separate species (Dowler et al. 2000). More research is needed to confirm that these are really two different species (M. Weksler pers. comm.).

Assessment Information [top]

Red List Category & Criteria: Extinct ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Tirira, D., Dowler, R., Boada, C. & Weksler, M.
Reviewer(s): Amori, G. (Small Nonvolant Mammal Red List Authority) & Schipper, J. (Global Mammal Assessment Team)
This species is listed as Extinct as specimens were last collected in 1934 and repeated surveys at several places on the island have failed to locate any individuals. The extinction is probably due to the introduction of the Black Rat Rattus rattus to the island in the late 1930s and was either the result of the introduction of pathogens to which the native species was susceptible or through direct competition with the introduced species. Other species introduced include House Mouse Mus musculus, the Norway Rat R. norvegicus and feral cats, all of which would also have had an impact on rodent decline and extinction.
Previously published Red List assessments:
2000 Extinct (EX)
1996 Endangered (EN)

Geographic Range [top]

Range Description: This species is endemic to Galápagos Islands. It was found on Santa Cruz (= Indefatigable), and Baltra (= South Seymour) Islands (Dowler et al., 2000).
Countries occurrence:
Regionally extinct:
Ecuador (Galápagos)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The last documented record was in 1934 (Patton and Hafner, 1983). This species is extinct (Dowler et al., 2000).
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: There is little information on the habitat and ecology of this species.
Systems: Terrestrial

Threats [top]

Major Threat(s): The introduction of the black rat (Rattus rattus) is the cause of the probable extinction of this species.

Conservation Actions [top]

Conservation Actions: There are not conservation measures.

Classifications [top]

3. Shrubland -> 3.6. Shrubland - Subtropical/Tropical Moist
suitability: Unknown  

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
8. Invasive & other problematic species & genes -> 8.1. Invasive non-native/alien species -> 8.1.2. Named species (Rattus rattus)
♦ timing: Past, Unlikely to Return    
→ Stresses
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.2. Competition

0. Root -> 4. Other

Bibliography [top]

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: Tirira, D., Dowler, R., Boada, C. & Weksler, M. 2008. Nesoryzomys indefessus. The IUCN Red List of Threatened Species 2008: e.T14708A4456597. . Downloaded on 28 November 2015.
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