Atelopus senex 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Bufonidae

Scientific Name: Atelopus senex
Species Authority: Taylor, 1952
Common Name(s):
English Pass Stubfoot Toad
Taxonomic Source(s): Frost, D.R. 2013. Amphibian Species of the World: an Online Reference. Version 5.6 (9 January 2013). Electronic Database. American Museum of Natural History, New York, USA. Available at:

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A2ace ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Bolaños, F., Chaves, G. & Barrantes, U.
Reviewer(s): Stuart, S.N., Chanson, J.S., Cox, N.A. & Young, B.E.
Listed as Critically Endangered because of a drastic population decline, estimated to be more than 80% over the last three generations, inferred from the apparent disappearance of most of the population, probably due to chytridiomycosis.
Previously published Red List assessments:
2004 Critically Endangered (CR)

Geographic Range [top]

Range Description: This species occurs in humid montane forest in central Costa Rica in the Cordilleras Central and Talamanca in Costa Rica from 1,100-2,200m asl.
Countries occurrence:
Possibly extinct:
Costa Rica
Lower elevation limit (metres): 1100
Upper elevation limit (metres): 2200
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This species was formerly abundant but (as of August 2007) it has not been seen since 1986 despite repeated searches; although further searches are needed to finally confirm the exinction of this species. It was formerly abundant on the slopes of Volcán Barva, but is now believed extinct there (Savage 2002).
Current Population Trend: Decreasing
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: It occurs and reproduces in stream margins in premontane rainforest and lower montane rainforest. It is a diurnal, stream-breeding species, and used to be found in great concentrations during the reproductive period from July to August (Savage 2002).
Systems: Terrestrial; Freshwater

Use and Trade [top]

Use and Trade: It is possibly extinct, and is unlikely to be in international trade any longer.

Threats [top]

Major Threat(s): The major threat is likely to be chytridiomycosis, leading to a catastrophic population decline, as has occurred in many other montane species of Atelopus. Other threats to this species might include climate change, collecting for the pet trade, and possibly pollution.

Conservation Actions [top]

Conservation Actions: The range of this species is protected by both Parque Nacional Tapantí and Parque Nacional Braulio Carrillo (although it is now believed extinct in the latter area). Further survey work is required to determine whether or not this species still persists. Given the threat of chytridiomycosis, surviving individuals might need to form the basis for the establishment of an ex-situ population.

Citation: Bolaños, F., Chaves, G. & Barrantes, U. 2008. Atelopus senex. The IUCN Red List of Threatened Species 2008: e.T54549A11165586. . Downloaded on 26 November 2015.
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