Atelopus balios 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Bufonidae

Scientific Name: Atelopus balios Peters, 1973
Common Name(s):
English Rio Pescado Stubfoot Toad
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 B1ab(i,iii) ver 3.1
Year Published: 2018
Date Assessed: 2016-07-16
Assessor(s): IUCN SSC Amphibian Specialist Group
Reviewer(s): Neam, K.
Contributor(s): Cisneros-Heredia, D.F., Coloma, L.A., Yánez-Muñoz, M., Bejarano-Muñoz, P. & Ron, S.R.
Facilitator/Compiler(s): Cisneros-Heredia, D.F.
Listed as Critically Endangered because of its small distribution, with an extent of occurrence (EOO) of approximately 55 km2, all individuals restricted to a single threat-defined location that is under severe pressure by habitat destruction and fragmentation due to expansion of the agricultural frontier and mining. Previously, during the 1980s, the species experienced a drastic population decline resulting in the disappearance of most subpopulations, due to habitat loss and possibly chytridiomycosis.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is known from only four localities in the provinces of Azuay, Cañar, and Guayas in the Pacific lowlands of south-western Ecuador, from 0–900 m asl. Its extent of occurrence (EOO) is 55 km2 and it occurs at a single threat-defined location.
Countries occurrence:
Additional data:
Continuing decline in extent of occurrence (EOO):Yes
Number of Locations:1
Upper elevation limit (metres):900
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The species had not been recorded since April 1995 despite repeated searches. Five visits to Rio Patul and Manta Real failed to record this species between 1997 and 2000 (Ron et al. 2011). This is now considered a very rare species and is only known from one subpopulation. One individual was rediscovered in October 2010 in the vicinity of Manta Real beside a river in an area dominated by farms and tropical rainforest (Hance 2011, Moore 2011, Ron et al. 2011), and subsequently, five males were collected along the Río Patul on the border of Azuay and Cañar in March 2011, five additional adults and tadpoles were collected in June 2011, and one additional male was collected in June 2012 (Coloma and Almeida-Reinoso 2012).
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:Unknown
All individuals in one subpopulation:Yes

Habitat and Ecology [top]

Habitat and Ecology:It is an inhabitant of lowland rainforest, and has been found on riverbanks, where it breeds along streams.
Systems:Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat:Yes
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade: There are no records of this species being utilized.

Threats [top]

Major Threat(s): Habitat degradation and loss, due to extension of the agricultural frontier (crops and livestock) and logging, mining, and pollution, are very serious threats. As with many other Atelopus species, this species declined during the 1980s. Chytridiomycosis was reported as a probable cause for the decline, and specimens collected at Rio Patul (elevation 350 m asl) in 1992 were infected by the fungus (A. Blasco-Zuñiga pers. comm. In: Ron et al. 2011, 2017).

Conservation Actions [top]

Conservation Actions: Conservation Actions
The range of the species does not include any protected areas, but it might occur in the nearby Manglares-Churute Ecological Reserve due to being close to the species' range (Ecuador Red List Assessment Workshop July 2016). Centro Jambatu de Investigación y Conservación de Anfibios is currently managing the ex situ breeding of an assurance colony, but further ex situ conservation measures could be adopted (Ecuador Red List Assessment Workshop July 2016).

Conservation Needed
In situ conservation is urgently needed to preserve the last species' habitat remnants. 

Research Needed
Further surveys are needed to establish the limits of this species range and determine if it occurs at other nearby localities, particularly in the Manglares-Churute Ecological Reserve. There is a need for monitoring its population status provided the ongoing threats to this range-restricted species.

Citation: IUCN SSC Amphibian Specialist Group. 2018. Atelopus balios. The IUCN Red List of Threatened Species 2018: e.T54491A98640710. . Downloaded on 16 October 2018.
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