Atelopus sorianoi 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Bufonidae

Scientific Name: Atelopus sorianoi
Species Authority: La Marca, 1983
Common Name(s):
English Cloud Forest Stubfoot Toad, Scarlet Harlequin Toad
Spanish Sapito Arlequin De Soriano
Taxonomic Source(s): Frost, D.R. 2014. Amphibian Species of the World: an Online Reference. Version 6 (27 January 2014). New York, USA. Available at: (Accessed: 27 January 2014).

Assessment Information [top]

Red List Category & Criteria: Critically Endangered () A2ace; B2ab(iii,v) ver 3.1
Year Published: 2010
Date Assessed: 2004-05-31
Needs updating
Assessor(s): Enrique La Marca, Argelia Rodríguez, Juan Elías García-Pérez
Reviewer(s): Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)
Listed as Critically Endangered because of a drastic population decline, estimated to be more than 80% over the last ten years, inferred from the apparent disappearance of most of the population (probably due to chytridiomycosis); and because its Area of Occupancy is less than 10 km2, all individuals are in a single location, and there is continuing decline in the extent and quality of its habitat, and in the number of mature individuals.
Date last seen: 1990
Previously published Red List assessments:
2004 Critically Endangered (CR)

Geographic Range [top]

Range Description:This species is known from a single stream in an isolated cloud forest, the Paramito de San Francisco, near the town of Guaraque, in Mérida State, Cordillera de Mérida, in Venezuela. It has the most restricted geographic range of any Venezuelan Atelopus species, and lives at an altitude of 2,400-2,718m asl.
Countries occurrence:
Possibly extinct:
Venezuela, Bolivarian Republic of
Lower elevation limit (metres):2400
Upper elevation limit (metres):2718
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:At the time of its discovery, this species was particularly abundant at the type locality. However, it is now extremely rare, or perhaps even extinct; the last record of the species was in 1990.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:It is an inhabitant of montane cloud forests. It is photophilic and lays egg chains in streams, where the tadpoles also develop.
Systems:Terrestrial; Freshwater

Threats [top]

Major Threat(s): Infection with Batrachochytrium dendrobatidis in this species was reported by Lampo et al. (2006). Local climate data indicate that one of the most severe dry seasons recorded in the region since 1970 coincided with epidemic events. In addition, clear cutting has greatly reduced the amount of available habitat for this species.

Conservation Actions [top]

Conservation Actions: The small range of this species does not include any protected areas. Surveys are needed to establish whether or not this species still survives, and a project aimed at evaluating their population status and at assessing environmental and climate conditions of the cloud forests of Mérida State in the Venezuelan Andes (where populations of this toad might occur in remote ridges and valleys) has been initiated. Ex-situ conservation action might also be required.

Classifications [top]

1. Forest -> 1.9. Forest - Subtropical/Tropical Moist Montane
suitability: Suitable  
5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability: Suitable  
1. Land/water protection -> 1.1. Site/area protection
3. Species management -> 3.4. Ex-situ conservation -> 3.4.1. Captive breeding/artificial propagation

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
  Subject to recent education and awareness programmes:Yes
5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.4. Unintentional effects: (large scale)
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

8. Invasive & other problematic species & genes -> 8.1. Invasive non-native/alien species -> 8.1.2. Named species (Batrachochytrium dendrobatidis)
♦ timing: Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

11. Climate change & severe weather -> 11.5. Other impacts
♦ timing: Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.3. Indirect ecosystem effects

1. Research -> 1.2. Population size, distribution & trends

Bibliography [top]

Barrio Amorós, C.L. 2004. Amphibians of Venezuela Systematic List, Distribution and References, An Update. Review of Ecology in Latin America 9(3): 1-48.

IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.2). Available at: (Accessed: 29 June 2010).

La Marca, E. 1983. A new frog of the genus Atelopus (Anura: Bufonidae) from a Venezuelan cloud forest. Milwaukee Public Museum Contributions in Biology and Geology: 1-12.

La Marca, E. 1995. Crisis de biodiversidad en anfibios de Venezuela: estudio de casos. In: Alonso-Amelot, M.E. (ed.), La Biodiversidad Neotropical y la Amenaza de las Extinciones, pp. 47-69. Universidad de Los Andes, Mérida.

La Marca, E. and Lötters, S. 1997. Monitoring of declines in Venezuelan Atelopus. In: Bohme,W., Bishoff, W. and Ziegler, T. (eds), Herpetologia Bonnensis, pp. 207-213. Society European Herpetology, Bonn.

La Marca, E. and Reinthaler, H.P. 1991. Population changes in Atelopus species of the Cordillera de Mérida, Venezuela. Herpetological Review: 125-128.

La Marca, E., Lips, K.R., Lötters, S., Puschendorf, R., Ibáñez, R., Rueda-Almonacid, J.V., Schulte, R., Marty, C., Castro, F., Manzanilla-Puppo, J., Garcia-Perez, J.E., Toral, E., Bolaños, F., Chaves, G., Pounds, J.A. and Young, B. 2005. Catastrophic population declines and extinctions in Neotropical harlequin frogs (Bufonidae: Atelopus). Biotropica: 190-201.

Lampo, M., Rodríguez-Contreras, A., La Marca , E. and Daszak, P. 2006a. A chytridiomycosis epidemic and a severe dry season precede the disappearance of Atelopus species from the Venezuelan Andes. The Herpetological Journal 16: 395-402.

Pounds, J.A., Bustamante, M.R., Coloma, L.A., Consuegra, J.A., Fogden, M.P.L., Foster, P.N., La Marca, E., Masters, K.L., Merino-Viteri, A., Puschendorf, R., Ron, S.R., Sánchez-Azofeifa, G.A., Still, C.J. and Young, B.E. 2006. Widespread amphibian extinctions from epidemic disease driven by global warming. Nature 439: 161-167.

Rodríguez, J.P. and Rojas-Suárez, F. 1995. Libro Rojo de la Fauna Venezolana. Provita, Fundación Polar, Caracas.

Vial, J.L. and Saylor, L. 1993. The status of amphibian populations. A compilation and analysis. IUCN/SSC Declining Amphibian Population Task Force. Working Document No. 1: iii + 98 pp.

Citation: Enrique La Marca, Argelia Rodríguez, Juan Elías García-Pérez. 2010. Atelopus sorianoi. In: The IUCN Red List of Threatened Species 2010: e.T54554A11166503. . Downloaded on 25 November 2015.
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