Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Rodentia Cricetidae

Scientific Name: Oryzomys gorgasi
Species Authority: Hershkowitz, 1971
Common Name(s):
English Gorgas's Rice Rat
Taxonomic Notes: Oryzomys curasoae (see separate listing) may be conspecific with this species.

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii) ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Ochoa, J., Gómez-Laverde, M., Weksler, M. & Timm, R.
Reviewer(s): McKnight, M. (Global Mammal Assessment Team) & Amori, G. (Small Nonvolant Mammal Red List Authority)
This species is listed as Endangered because its area of occupancy is probably less than 500 km2, its distribution is severely fragmented, it is known from fewer than five localities, and the extent of coastal wetland habitat is declining.
Previously published Red List assessments:
1996 Critically Endangered (CR)

Geographic Range [top]

Range Description: This species is known from specimens in the eastern coast of the gulf of Maracaibo in Venezuela at sea level (Sanchez et al. 2001; Sanchez Ojera and Vaz 2004) and from the type locality in Colombia. Locals report a mangrove rat between the two locations but there are no voucher specimens (J. Ochoa pers. comm.).
Countries occurrence:
Colombia; Venezuela, Bolivarian Republic of
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This species is rare (Sanchez et al. 2001). In some places it is locally extinct because the species has been displaced by Rattus rattus (J. Ochoa pers. comm.).
Current Population Trend: Decreasing
Additional data:
Population severely fragmented: Yes

Habitat and Ecology [top]

Habitat and Ecology: This species occurs in coastal environments of mangroves, freshwater inundated grasslands, and salt marsh; it is terrestrial and semi aquatic, and is omnivorous (Sanchez et al. 2001).
Systems: Terrestrial

Threats [top]

Major Threat(s): The major threats are changes in species dynamics by competition with Rattus rattus; other human disturbances also are important in Venezuela (Sanchez et al. 2001).

Conservation Actions [top]

Conservation Actions: In Venezuela the locality is within a protected area (Sanchez et al. 2001).

Classifications [top]

1. Forest -> 1.7. Forest - Subtropical/Tropical Mangrove Vegetation Above High Tide Level
suitability: Suitable  
4. Grassland -> 4.6. Grassland - Subtropical/Tropical Seasonally Wet/Flooded
suitability: Suitable  
5. Wetlands (inland) -> 5.4. Wetlands (inland) - Bogs, Marshes, Swamps, Fens, Peatlands
suitability: Suitable  
5. Wetlands (inland) -> 5.16. Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools
suitability: Marginal  

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Conservation sites identified:Yes, over entire range
In-Place Species Management
In-Place Education
6. Human intrusions & disturbance -> 6.1. Recreational activities
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.2. Species disturbance

8. Invasive & other problematic species & genes -> 8.1. Invasive non-native/alien species -> 8.1.2. Named species (Rattus rattus)
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.2. Competition

Bibliography [top]

Sánchez, J., Ochoa, J. G. and Voss, R. S. 2001. Rediscovery of Oryzomys gorgasi (Rodentia: Muridae), with notes on taxonomy and natural history. Mammalia 65: 205-214.

Citation: Ochoa, J., Gómez-Laverde, M., Weksler, M. & Timm, R. 2008. Oryzomys gorgasi. The IUCN Red List of Threatened Species 2008: e.T15596A4874427. . Downloaded on 09 October 2015.
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