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The IUCN Red List of Threatened Species™
ISSN 2307-8235 (online)
IUCN 2020: T54948A85872712
Scope(s): Global
Language: English
Nymphargus balionotus, Mindo Glassfrog
Assessment by: IUCN SSC Amphibian Specialist Group
View on www.iucnredlist.org
Citation: IUCN SSC Amphibian Specialist Group. 2020. Nymphargus balionotus. The IUCN Red List of
Threatened Species 2020: e.T54948A85872712. https://dx.doi.org/10.2305/IUCN.UK.2020-
3.RLTS.T54948A85872712.en
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THE IUCN RED LIST OF THREATENED SPECIES™
Taxonomy
Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Centrolenidae
Scientific Name:ÊÊNymphargus balionotus (Duellman, 1981)
Synonym(s):
• Centrolene balionota (Duellman, 1981) [orth. error]
• Centrolene balionotum (Duellman, 1981)
• Centrolenella balionota Duellman, 1981
• Cochranella balionota (Duellman, 1981)
• Nymphargus balionota (Duellman, 1981) [orth. error]
Common Name(s):
• English: Mindo Glassfrog, Mottled Glassfrog
• Spanish; Castilian: Rana de Cristal de Puntos Canela
Taxonomic Source(s):
Frost, D.R. 2020. Amphibian Species of the World: an Online Reference. Version 6.0. American Museum
of Natural History, New York, USA Available at:
http://research.amnh.org/herpetology/amphibia/index.html.
Guayasamin, J.M., Cisneros-Heredia, D.F., Vieira, J., Kohn, S., Gavilanes, G., Lynch, R.L., Hamilton, P.S. and
Maynard, R.J. 2019. A new glassfrog (Centrolenidae) from the Chocó-Andean Río Manduriacu Reserve,
Ecuador, endangered by mining. PeerJ 7: p.e6400.
Taxonomic Notes:
Duellman (1981) originally placed the taxon in the genus Centrolenella, which was subsequently
designated to Cochranella by Ruiz-Carranza and Lynch (1991) based on the absence of humeral spines in
males from specimens collected at Campamento Chancos, Valle del Cauca. However, Cisneros-Heredia
and McDiarmid (2006) verified the presence of humeral spines in the material described by Duellman
(1981), thus combining the taxon with Centrolene; the Colombian material reported by Lynch and Ruiz-
Carranza (1996) were therefore presumed to be of a distinct lineage (Cisneros-Heredia and McDiarmid
2006). The lack of clarity regarding Colombian specimens is reflected in many published accounts (e.g.
Acosta-Galvis 2000, Cisneros-Heredia and Yánez-Muñoz 2007, Guayasamin and Frenkel 2018).
Later, in a monographic revision of the glassfrog family, Centrolenidae, Guayasamin et al. (2009)
underscored the difficulty of substantively designating the taxon at the generic level, and regarded the
taxon as incertae sedis within the subfamily Centroleninae. Finally, after incorporating mitochondrial
sequences into a phylogenetic analysis of the family, Guayasamin et al. (2019) determined its placement
within Nymphargus based on recent material from the Río Manduriacu Reserve, Imbabura, Ecuador
(Maynard et al. 2020). New material for N. balionotus from Colombia has not been reported in recent
decades. Thus, it is not currently possible to resolve whether or not the subpopulation from
Campamento Chancos is representative of a distinct lineage from those in Ecuador, as suggested by
Cisneros-Heredia and McDiarmid (2006). However, it is plausible that this scenario is correct based on
available information; in addition to lacking humeral spines, the records from Campamento Chancos are
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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well separated from, and substantially lower in elevation than all other specimens (Maynard et al.
2020).
Assessment Information
Red List Category & Criteria: Endangered B1ab(iii) ver 3.1
Year Published: 2020
Date Assessed: July 3, 2019
Justification:
Listed as Endangered in view of its extent of occurrence (EOO) of 446 km2, its occurrence in two threat-
defined locations, and a continuing decline in the extent and quality of its habitat throughout its range
along the western slope of the Cordillera Occidental of the Andes in Ecuador and Colombia.
Previously Published Red List Assessments
2004 – Vulnerable (VU)
https://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T54948A11231013.en
Geographic Range
Range Description:
This species is known from along the western slope of the Cordillera Occidental of the Andes in Ecuador
and Colombia. In Ecuador, it is was formerly known only from the type locality: Mindo, in Pichincha
Province, at 1,540 m asl (Duellman 1981), however the species was also recorded from near western
Carchi Province in 1984 (Cisneros-Heredia and Yanez-Muñoz 2007), in Cotopaxi Province in 2005
(Arteaga et al. 2013), and most recently in Río Manduriacu Reserve, Imbabura Province, from
1,116–1,285 m asl (Maynard et al. 2020). In Colombia, historical records come from Restrepo in Valle de
Cauca Department (Ruiz and Lynch 1991, Lynch and Suárez 2004) and a specimen near El Tambo in
Cauca Department, between 460 and 800 m asl (Duellman 1981). Information associated with the latter
specimen is problematic (see discussion in Maynard et al. 2020) and the Campamento Chancos
subpopulation is speculated to be a distinct lineage by Cisneros-Heredia and McDiarmid (2006);
therefore, both are considered Presence Uncertain in this assessment. Its estimated extent of
occurrence (EOO) is 446 km2, which represents two threat-defined locations.
Country Occurrence:
Native, Extant (resident): Colombia; Ecuador
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
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Distribution Map
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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Population
This relatively small species was described primarily based on a series of 13 adult males collected over
two nights (7-8 April 1975) at the type locality, just 3.5 km NE of Mindo, Ecuador (Duellman 1981). Also
referenced in the species' description was a single specimen collected in March 1938, from a site ca 330
km north of the type locality, near El Tambo, Cauca, Colombia. Unfortunately, information associated
with this latter specimen is scarce and problematic (see discussion in Maynard et al. 2020).
Since the description, there have been few additional observations. In Ecuador, one specimen was
collected at a site near Cabeceras del Río Baboso, western Carchi province in November 1984 (Cisneros-
Heredia and Yanez-Muñoz 2007), and a second specimen was collected from NE of La Maná, Río Lomapi,
Cotopaxi in August 2005 (Arteaga et al. 2013). The Río Lomapi site has apparently not been resurveyed
since the initial record from 2005 (Maynard et al. 2020). In Colombia, nine specimens were collected
from Campamento Chancos, Vereda Campo Alegre, Restrepo municipality, Valle del Cauca in 1983
and/or 1984 (Lynch and Ruiz-Carranza 1996, Maynard et al. 2020), ca. 160 km north from the single
record in Cauca Department. Similar to the specimen from Cauca, few details have been published on
the material or the site of collection. The species was documented as reasonably common in Colombia
in the previous assessment (IUCN 2004), although this cannot be verified. The El Tambo locality in
Colombia was surveyed in 2000, but this species was not found and the site has not been revisited since
then (J. Guerrero-Vargas pers. comm. 2016). Ospina-Sarria et al. (2015) indicate that the status of
amphibian populations from Campamento Chancos are difficult to determine due to the site being in a
region with “problems of public order,” which suggests that there have not been surveys there since
1993 (Maynard et al. 2020).
Numerous attempts to search for the species in Ecuador, even within seemingly appropriate habitat
within its historical range and nearby localities, proved unsuccessful (Cisneros-Heredia and Yanez-Munoz
2007, Ron et al. 2011, Arteaga et al. 2013). Finally, in 2018, a breeding subpopulation was discovered at
the Río Manduriacu Reserve, Imbabura, Ecuador (Guayasamin et al. 2019, Maynard et al. 2020). Prior to
this observation, only a single specimen was found since 1984 (at Rio Lomapi in 2005); it is not clear as
to whether this lack of observations was due to a lack of surveys or if the population had genuinely
declined. A total of 39 observations, including adults, subadults, metamorphs and egg masses, were
made from four streams at the Río Manduriacu Reserve during three expeditions between February
2018 and December 2019 (Maynard et al. 2020). Surveys on a number of other streams at higher and
lower elevations, and more interior in the canyon, during the same time period did not yield additional
records. The subpopulation at the Río Manduriacu Reserve is currently the only known extant
subpopulation of this glassfrog (Maynard et al. 2020). Ecuadorean subpopulations from Mindo and
Cabeceras del Río Baboso are likely extirpated based on surveys in those areas since the initial records
(Ron et al. 2011).
Current Population Trend:ÊÊDecreasing
Habitat and Ecology (see Appendix for additional information)
It is an arboreal species, living on vegetation next to streams in humid lowland tropical forest, lower
montane forest, and cloud forest. It seems to require intact forest. It breeds in streams, with the eggs
laid on the underside of leaves (Maynard et al. 2020). Males sing perched on leaves in plants and ferns
that hang 1-5 m above the water (Guayasamín and Frenkel 2018, Maynard et al. 2020). Males call more
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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often when there was light or steady rain and relative humidity is greater than 90% (Maynard et al.
2020).
Systems:ÊÊTerrestrial, Freshwater (=Inland waters)
Use and Trade (see Appendix for additional information)
There are no records of this species being utilized.
Threats (see Appendix for additional information)
The major threat is habitat loss as a result of mining activities (Roy et al. 2018), deforestation for
agricultural development (including the planting of illegal crops), logging, and human settlement. Other
threats include the introduction of exotic predatory fish, and pollution resulting from the spraying of
illegal crops.
Most of the habitat at Río Manduriacu Reserve is undisturbed, however the mining company, Cerro
Quebrado, a subsidiary of BHP Billiton, is threatening to transform much of the canyon (including the
reserve) into an open-pit mine (Maynard et al. 2020). Illegal and uncontrolled logging has caused a
dramatic reduction in forest cover in the area surrounding Río Manduriacu Reserve in the last two
decades (Guayasamin et al. 2019).
Conservation Actions (see Appendix for additional information)
Conservation Actions In-Place
A breeding subpopulation discovered at the Rio Manduriacu Reserve, Imbabura, Ecuador is the only
known extant subpopulation documented within the last 20+ years (Maynard et al. 2020), although
mining activities threaten the longevity of this reserve (Guayasamin et al. 2019, Maynard et al. 2020).
The community project initiated by Fundación EcoMinga and Fundación Condor Andino in Santa Rosa de
Manduriacu is working to ensure proper enforcement of the reserve's boundary and prevent access of
illegal mining activities at the reserve (Maynard et al. 2020). Due to close proximity, the species might
also occur in the adjacent Cotacachi-Cayapas Ecological Reserve, which is less accessible and receives
support and protection from mining by the national government that are currently not extended to
private reserves or protected forests (R. Maynard pers. comm. June 2019). In Colombia, it might occur in
Parque Nacional Natural Munchique.
Conservation Needed
There is clearly a need for improved habitat protection and management at sites which this species is
known to occur.
Research Needed
In light of the substantial rise in mining activity around its range (Roy et al. 2018), more survey work is
needed to identify additional subpopulations of the species and its actual range in both Ecuador and
Colombia (R. Maynard pers. comm. June 2019). Further research is also required to fully resolve
whether or not the Colombian subpopulations are indeed differentiated from the subpopulations in
Ecuador (R. Maynard pers. comm. June 2019), as suggested by Cisneros-Heredia and McDiarmid (2006).
Credits
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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Assessor(s): IUCN SSC Amphibian Specialist Group
Reviewer(s): Chanson, J.S.
Contributor(s): Cisneros-Heredia, D.F., Wild, E., Guerrero, J.A., Lynch, J., Mueses-Cisneros,
J.J., Coloma, L.A., Maynard, R., Ron, S.R. & Bolívar, W.
Facilitator(s) and
Compiler(s):
Neam, K. & NatureServe
Authority/Authorities: IUCN SSC Amphibian Specialist Group
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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Bibliography
Acosta-Galvis, A.R. 2000. Ranas, Salamandras y Caecilias (Tetrapoda: Amphibia) de Colombia. Biota
Colombiana 1(3): 289-319.
Arteaga-Navarro, A., Bustamante, L. and Guayasamin, J.M. 2013. The Amphibians and Reptiles of Mindo.
Universidad Tecnológica Indoamérica, Quito.
Cisneros-Heredia, D.F. and McDiarmid, R.W. 2006. A new species of the genus Centrolene (Amphibia:
Anura: Centrolenidae) from Ecuador with comments on the taxonomy and biogeography of glassfrogs.
Zootaxa 1244: 1–32.
Cisneros-Heredia, D.F., and Yánez-Muñoz, M.H. 2007. A new species of glassfrog (Centrolenidae) from
the southern Andean foothills on the west Ecuadorian region. South American Journal of Herpetology 2:
1-10.
Duellman, W.E. 1981. Three new species of centrolenid frogs from the Pacific versant of Ecuador and
Colombia. Occasional Papers of the Museum of Natural History of the University of Kansas: 1-9.
Guayasamin, J.M. and Frenkel, C. 2018. Cochranella balionota AmphibiaWebEcuador. Version 2019.0.
Available at: https://bioweb.bio/faunaweb/amphibiaweb/FichaEspecie/Cochranella%20balionota.
Guayasamin, J.M., Castroviejo-Fisher, S., Trueb, L., Ayarzagüena, J., Rada, M. and Vilà, C. 2009.
Phylogenetic systematics of Glassfrogs (Amphibia: Centrolenidae) and their sister taxon Allophryne
ruthveni. Zootaxa 2100: 1-97.
Guayasamin, J.M., Cisneros-Heredia, D.F., Vieira, J., Kohn, S., Gavilanes, G., Lynch, R.L., Hamilton, P.S. and
Maynard, R.J. 2019. A new glassfrog (Centrolenidae) from the Chocó-Andean Río Manduriacu Reserve,
Ecuador, endangered by mining. PeerJ 7: p.e6400.
IUCN. 2020. The IUCN Red List of Threatened Species. Version 2020-3. Available at: www.iucnredlist.org.
(Accessed: 10 December 2020).
Lynch, J.D. and Ruiz-Carranza, P.M. 1996. A remarkable new centrolenid frog from Colombia with a
review of nuptial excrecences in the family. Herpetologica 52(4): 525-535.
Lynch, J.D. and Suárez-Mayorga, A.M. 2004. Catálogo de anfibios en el Chocó Biogeográfico. In: J.O.
Rangel (ed.), Colombia Diversidad Biótica IV, El Chocó Biogeográfico/Costa Pacífica. Volumen I, pp. 633-
668. Universidad Nacional de Colombia, Instituto de Ciencias Naturales, Conservación Internacional,
Bogotá, Colombia.
Maynard, R.J., Trageser, S.J., Kohn, S., Hamilton, P.H., Culebras, J. and Guayasamin, J.M. 2020. Discovery
of a reproducing population of the Mindo Glassfrog, Nymphargus balionotus (Duellman, 1981), at the
Río Manduriacu Reserve, Ecuador, with a literature review and comments on its natural history,
distribution, and conservation status. Amphibian and Reptile Conservation 14(2): 172–184 (e245).
Ospina-Sarria J.J., Velásques Trujillo, D.A. and W. Bolívar-G. 2015. First records of the twoo poorly know
Terrarana frogs Pristimantis esmeraldas (Guayasamin, 2004) and Strabomantis necerus (Lynch, 1975)
(Amphibia Anura Craugastoridae) for Colombia. Herpetology Notes 8: 27-30.
Ron, S.R., Guayasamin, J.M and Menéndez-Guerrero, P. 2011. Biodiversity and Conservation Status of
Amphibians of Ecuador. In: H. Heatwole, C.L. Barrio-Amoros and H.W. Wilkinson (eds), Amphibian
Biology, pp. 129-170. Surrey Beatty & Soons PTY Limited, Baulkham Hills, Australia.
Roy, B.A., Zorrilla, M., Endara, L., Thomas, D.C., Vandegrift, R., Rubenstein, J.M., Policha, T., Rios-Touma,
B. and Read, M., 2018. New mining concessions could severely decrease biodiversity and ecosystem
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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services in Ecuador. Tropical Conservation Science 11: 1–20.
Ruiz-Carranza, P.M. and Lynch, J.D. 1991. Ranas Centrolenidae de Colombia I. Propuesta de una nueva
clasificación genérica. Lozania (Acta Zoológica colombiana) 57: 1-30.
Ruiz-Carranza, P.M., Ardila-Robayo, M.C. and Lynch, J.D. 1996. Lista actualizada de la fauna de Amphibia
de Colombia. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales 20(77): 365-
415.
Citation
IUCN SSC Amphibian Specialist Group. 2020. Nymphargus balionotus. The IUCN Red List of Threatened
Species 2020: e.T54948A85872712. https://dx.doi.org/10.2305/IUCN.UK.2020-
3.RLTS.T54948A85872712.en
Disclaimer
To make use of this information, please check the Terms of Use.
External Resources
For Supplementary Material, and for Images and External Links to Additional Information, please see the
Red List website.
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
8
Appendix
Habitats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Habitat Season Suitability Major
Importance?
1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland Resident Suitable Yes
1. Forest -> 1.9. Forest - Subtropical/Tropical Moist Montane Resident Suitable Yes
5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent
Rivers/Streams/Creeks (includes waterfalls)
Resident Suitable Yes
Threats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Threat Timing Scope Severity Impact Score
1. Residential & commercial development -> 1.1.
Housing & urban areas
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
2. Agriculture & aquaculture -> 2.1. Annual &
perennial non-timber crops -> 2.1.1. Shifting
agriculture
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
2. Agriculture & aquaculture -> 2.1. Annual &
perennial non-timber crops -> 2.1.2. Small-holder
farming
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
2. Agriculture & aquaculture -> 2.3. Livestock farming
& ranching -> 2.3.2. Small-holder grazing, ranching or
farming
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
3. Energy production & mining -> 3.2. Mining &
quarrying
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
5. Biological resource use -> 5.3. Logging & wood
harvesting -> 5.3.3. Unintentional effects:
(subsistence/small scale) [harvest]
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.2. Ecosystem degradation
8. Invasive and other problematic species, genes &
diseases -> 8.1. Invasive non-native/alien
species/diseases -> 8.1.1. Unspecified species
Ongoing - - Low impact: 3
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
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Stresses: 2. Species Stresses -> 2.1. Species mortality
9. Pollution -> 9.3. Agricultural & forestry effluents ->
9.3.4. Type Unknown/Unrecorded
Ongoing - - Low impact: 3
Stresses: 1. Ecosystem stresses -> 1.2. Ecosystem degradation
Conservation Actions in Place
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Action in Place
In-place land/water protection
Occurs in at least one protected area: Yes
Conservation Actions Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Action Needed
1. Land/water protection -> 1.1. Site/area protection
1. Land/water protection -> 1.2. Resource & habitat protection
2. Land/water management -> 2.1. Site/area management
Research Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Research Needed
1. Research -> 1.1. Taxonomy
1. Research -> 1.2. Population size, distribution & trends
Additional Data Fields
Distribution
Estimated extent of occurrence (EOO) (km²): 446
Number of Locations: 2
Lower elevation limit (m): 460
Upper elevation limit (m): 1,540
Population
Population severely fragmented: Yes
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
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Habitats and Ecology
Continuing decline in area, extent and/or quality of habitat: Yes
Movement patterns: Not a Migrant
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
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The IUCN Red List of Threatened Species™
ISSN 2307-8235 (online)
IUCN 2020: T54948A85872712
Scope(s): Global
Language: English
The IUCN Red List Partnership
The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species
Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership.
The IUCN Red List Partners are: Arizona State University; BirdLife International; Botanic Gardens
Conservation International; Conservation International; NatureServe; Royal Botanic Gardens, Kew;
Sapienza University of Rome; Texas A&M University; and Zoological Society of London.
THE IUCN RED LIST OF THREATENED SPECIES™
© The IUCN Red List of Threatened Species: Nymphargus balionotus – published in 2020.
https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T54948A85872712.en
12