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Pseudemys gorzugi 

Scope:Global
Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_onStatus_vu_offStatus_en_offStatus_cr_offStatus_ew_offStatus_ex_off

Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Testudines Emydidae

Scientific Name: Pseudemys gorzugi
Species Authority: Ward, 1984
Common Name(s):
English Rio Grande Cooter
Spanish Jicotea
Synonym(s):
Pseudemys concinna (LeConte, 1830) subspecies gorzugi Ward, 1984
Taxonomic Notes: Elevated to full species status by Ernst (1990) and Seidel (1994) from initial status of subspecies of Pseudemys concinna.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2013
Date Assessed: 2010-08-01
Assessor(s): van Dijk, P.P.
Reviewer(s): Horne, B.D., Mittermeier, R.A., Philippen, H.-D., Quinn, H.R., Rhodin, A.G.J., Shaffer, H.B. & Vogt, R.C
Contributor(s): Lavin, P., Hammerson, G.A. & Mendoza-Quijano, F.
Justification:

Pseudemys gorzugi has a large extent of occurrence (along the Pecos-lower Rio Grande basin, from New Mexico, US to Tamaulipas, Mexico). However, the area of occupancy is much smaller (perhaps less than 2,000 km2). The habitat is declining due to pollution and water control and diversion along the length of the main river. The species is also collected for the pet trade, and the population may be declining as a direct result of this.

Pseudemys gorzugi is assessed as Near Threatened on the basis that it nearly meets Vulnerable under criterion B1. However, further research is urgent to determine whether a threatened status is appropriate for this species, based on reported population fragmentation and decline.

Previously published Red List assessments:
1996 Lower Risk/near threatened (LR/nt)

Geographic Range [top]

Range Description:

Pseudemys gorzugi inhabits the Pecos-lower Rio Grande basin from New Mexico through Texas, USA, and Coahuila, Nuevo Leon and Tamaulipas, Mexico (Iverson 1992, Seidel 1994). Not recorded from the Rio Grande at or above the Big Bend region, nor from the San Fernando.

Countries occurrence:
Native:
Mexico (Coahuila, Nuevo León, Tamaulipas); United States (New Mexico, Texas)
Upper elevation limit (metres): 1082
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population:

Scant information is available on population status, densities, or population trends; it has been noted as locally common in the Mexican part of its range (P. Lavin pers. comm. 2005). Forstner et al. (2006) carried out range-wide surveys and found populations of the species concentrated in only a few stretches of the U.S. tributaries, whereas the species has minimal genetic structure across its range (Bailey et al. 2008).

Current Population Trend: Unknown
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology:

Restricted to the mainstream of the Pecos and Rio Grande, and the lowermost few miles of tributaries (Ward 1984). Occurs as high as 1,082 m altitude in New Mexico (Degenhardt and Christiansen, in Ernst et al. 1994). Apparently absent from the Texas side of the lower Rio Grande (Ward 1984). 


Examined gut contents were entirely vegetarian (Legler, in Ernst and Lovich 2009), although the species has also been thought to be omnivorous (Degenhardt et al. 1996, Ernst and Lovich 2009).

Animals reach up to 37.2 cm carapace length (CL) (Ernst and Lovich 2009). Limited information is available on reproduction: a clutch size of nine eggs has been reported; whether females produce multiple clutches remains unknown. Age and size at maturity remain unrecorded.

Systems: Terrestrial; Freshwater

Use and Trade [top]

Use and Trade: Some animals are collected for the pet trade (Bailey et al. 2008).

Threats [top]

Major Threat(s):

An apparent absence of the species over a 160-km stretch of the lower Pecos was attributed to river pollution by natural gas and oilfield runoff (Ward 1984). Water diversion, runoff interception, groundwater pumping and other intensive water usage in the basin mean that the Rio Grande frequently runs dry before reaching the sea, while floodplain lake habitat has been lost after the construction of flood mitigation dams and infrastructure. These processes fragment populations and impede repopulation of depleted populations and gene flow.

The species is also considered to be under potentially serious threat from collection for the pet trade and wanton killing by fishermen (Forstner pers. comm. 2005, Bailey et al. 2008). Bailey et al. (2008) also reported an apparent absence of juveniles in the Texas populations of P. gorzugi, whereas their searches for juveniles in New Mexico were successful; they expressed their concerns for future population dynamics of Texas populations.

Conservation Actions [top]

Conservation Actions:

Turtles in general are protected from exploitation under Mexican wildlife and natural resource legislation. The species may occur, but has apparently not been confirmed, in the Bitter Lakes Wildlife Refuge of New Mexico. Surveys for the species in the Big Bend NP - Maderas del Carmen FFPA - Rio Grande National Scenic River – Amistad NRA, and the Lower Rio Grande Valley NWR, areas are desirable. Surveys of the Canon de Santa Elena FFPA have failed to record the species (MX Red List Workshop participants 2005).

Studies of its natural history and conservation status are warranted. Based on study results, the species may warrant specific legal protection in the USA. Commercial pet trade demand for the species can probably be met through captive breeding.

Classifications [top]

5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability: Suitable  major importance:Yes
5. Wetlands (inland) -> 5.5. Wetlands (inland) - Permanent Freshwater Lakes (over 8ha)
suitability: Unknown  
1. Land/water protection -> 1.2. Resource & habitat protection
2. Land/water management -> 2.1. Site/area management
2. Land/water management -> 2.2. Invasive/problematic species control
2. Land/water management -> 2.3. Habitat & natural process restoration
3. Species management -> 3.4. Ex-situ conservation -> 3.4.1. Captive breeding/artificial propagation
4. Education & awareness -> 4.3. Awareness & communications
5. Law & policy -> 5.1. Legislation -> 5.1.2. National level
5. Law & policy -> 5.1. Legislation -> 5.1.4. Scale unspecified
5. Law & policy -> 5.2. Policies and regulations
5. Law & policy -> 5.4. Compliance and enforcement -> 5.4.3. Sub-national level

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Unknown
In-Place Species Management
In-Place Education
  Included in international legislation:No
  Subject to any international management/trade controls:No
4. Transportation & service corridors -> 4.1. Roads & railroads
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.1. Intentional use: (subsistence/small scale)
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

6. Human intrusions & disturbance -> 6.1. Recreational activities
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.2. Species disturbance

6. Human intrusions & disturbance -> 6.2. War, civil unrest & military exercises
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.2. Species disturbance

7. Natural system modifications -> 7.2. Dams & water management/use -> 7.2.9. Small dams
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

7. Natural system modifications -> 7.2. Dams & water management/use -> 7.2.10. Large dams
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

8. Invasive & other problematic species & genes -> 8.2. Problematic native species
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality
  • 2. Species Stresses -> 2.2. Species disturbance

9. Pollution -> 9.2. Industrial & military effluents -> 9.2.1. Oil spills
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

9. Pollution -> 9.2. Industrial & military effluents -> 9.2.3. Type Unknown/Unrecorded
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

11. Climate change & severe weather -> 11.1. Habitat shifting & alteration
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

11. Climate change & severe weather -> 11.2. Droughts
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends
3. Monitoring -> 3.4. Habitat trends

♦  Pets/display animals, horticulture
 National : ✓  International : ✓ 

Bibliography [top]

Bailey, L.A., Dixon, J.R., Hudson, R. and Forstner, M.R.J. 2008. Minimal Genetic Structure in the Rio Grande Cooter (Pseudemys Gorzugi). Southwestern Naturalist 53(3): 406-411.

Ernst, C.H. 1990. Pseudemys gorzugi. Catalogue of American Amphibians and Reptiles 461: 1-2.

Ernst, C.H. and Lovich, J.E. 2009. Turtles of the United States and Canada. Second edition. Johns Hopkins University Press, Baltimore.

Ernst, C.H., Lovich, J.E. and Barbour, R.W. 1994. Turtles of the United States and Canada. Smithsonian, Washington, DC. 578 pp.

IUCN. 2011. IUCN Red List of Threatened Species (ver. 2011.1). Available at: http://www.iucnredlist.org. (Accessed: 16 June 2011).

Iverson, J.B. 1992. A Revised Checklist with Distribution Maps of the Turtles of the World. Richmond, Indiana. (Privately published).

Seidel, M.E. 1994. Morphometric analysis and taxonomy of cooter and red-bellied turtles in the North American genus Pseudemys (Emydidae). Chelonian Conservation and Biology 1(2): 117-130.

Ward, J.P. 1984. Relationships of Chrysemys Turtles of North America. Special Publications, the Museum, Texas Tech University: 1-50.


Citation: van Dijk, P.P. 2013. Pseudemys gorzugi. The IUCN Red List of Threatened Species 2013: e.T18459A8297596. . Downloaded on 04 May 2016.
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