Aegialomys galapagoensis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Rodentia Cricetidae

Scientific Name: Aegialomys galapagoensis (Waterhouse, 1839)
Common Name(s):
English Galapagos Rice Rat, Galapagos Oryzomys
Oryzomys bauri Allen, 1892
Oryzomys galapagoensis (Waterhouse, 1839)
Taxonomic Notes: Oryzomys is a generic synonym (Weksler et al. 2006). Musser and Carleton (1993) note that this taxon has two subspecies: A. g. bauri which occurs on Santa Fe Island (= Barrington) and A. g. galapagoensis which occurred on San Cristobal Island (= Chatham) and which is now said to be extinct (Dowler et al. 2000). Patton and Hafner (1983) demonstrated that the two populations are conspecific.

Assessment Information [top]

Red List Category & Criteria: Vulnerable D2 ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Tirira, D., 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 Vulnerable due to a very small or restricted population with only one remaining location, which is threatened by the possibility of the introduction of exotic species to the island. The species is not currently in decline, however, the only other population of was extirpated from a neighboring island due to exotic species introductions - thus this species is susceptible to extinction in the future should invasive species be introduced.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is endemic to the Galápagos Islands. It occurs only on Sante Fe (= Barrington) Island, and previously occurred on San Cristobal (= Chatham) Island (Musser and Carleton, 2005). A. galapagoensis was first described from specimens collected from Santa Cruz Island by Charles Darwin in 1835. Later studies suggested that A. bauri from Santa Fe, and A. galapagoensis were so similar that they may be considered conspecific (Patton and Hafner, 1983).
Countries occurrence:
Ecuador (Galápagos)
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species includes two populations: A. g. galapagoensis occurs in San Cristobal Island, which is extinct (Dowler et al. 2000; Tirira 2001); and A. g. bauri occurs in Santa Fe Island, where it is common (Dowler et al. 2000; Tirira 2001).
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Its ecology and natural history are poorly known. It is terrestrial and solitary.

Threats [top]

Major Threat(s): The history of the decline and likely extinction of the population on San Cristobal Island, with the increase and spread of introduced species has been well documented (Dowler et al. 2000). The introduction of exotic rats (Rattus rattus) or mice (Mus musculus) to Santa Fe Island remains the main threat to the species. History suggests that the species could easily go extinct due to invasive predators and competitor species and this should be a conservation priority.

Conservation Actions [top]

Conservation Actions: Control exotic species and access to the island, and enact a program to prevent the introduction of common rats.

Classifications [top]

3. Shrubland -> 3.5. Shrubland - Subtropical/Tropical Dry
3. Shrubland -> 3.6. Shrubland - Subtropical/Tropical Moist
0. Root -> 18. Unknown
2. Land/water management -> 2.1. Site/area management
2. Land/water management -> 2.2. Invasive/problematic species control
3. Species management -> 3.2. Species recovery

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education
8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.2. Named species [ Mus musculus ]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.2. Competition

8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.2. Named species [ Rattus rattus ]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.2. Competition

1. Research -> 1.6. Actions
2. Conservation Planning -> 2.1. Species Action/Recovery Plan
3. Monitoring -> 3.1. Population trends

Bibliography [top]

Dowler, R. C. 2000. Rediscovery of rodents (Genus Nesoryzomys) considered extinct in the Galapagos Islands. Oryx 34(2): 109-118.

Musser, G.G. and Carleton, M.D. 1993. Family Muridae. In: D.E. Wilson and D.A. Reeder (eds), Mammal species of the world: A taxonomic and geographic reference, pp. 501-736. Smithsonian Institution Press, Washington, DC, USA.

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.

Patton, J. L. and Hafner, M. S. 1983. Biosystematics of the native rodents of the Galapagos Archipelago, Ecuador. In: Bowman, R. I., Benson, M. and Leviton, A.E. (eds), Patterns of Evolution in Galapagos Organisms, pp. 539–568.

Tirira, D. 2001. Libro Rojo de los Mamíferos del Ecuador. Sociedad para la Investigación y Monitoreo de la Biodiversidad Ecuatoriana (SIMBIOE) / Ecociencias / Ministerio del Ambiente / UICN. Publicación Especial sobre los Mamíferos del Ecuador, Quito, Ecuador.

Weksler, M., Percequillo, A.R. and Voss, R.S. 2006. Ten new genera of Oryzomyine rodents (Cricetidae: Sigmodontinae). American Museum Novitates 3537: 1-29.

Citation: Tirira, D., Boada, C. & Weksler, M. 2008. Aegialomys galapagoensis. In: . The IUCN Red List of Threatened Species 2008: e.T15595A4872932. . Downloaded on 18 June 2018.
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