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El Rincon Stream Frog

Pleurodema somuncurense


The Critically Endangered El Rincon stream frog exists on a single plateau in Argentinian Patagonia. Though temperatures in the region often plummet below freezing, the frog avoids the cold by spending its life in streams whose waters are heated by permanent thermal springs.

The genus of frogs to which this species belongs, Pleurodema, diverged from all other amphibians around 55 million years ago. This means they are as closely related to other frogs as a mongoose is to a polar bear!

This frog is a micro-endemic, and occupies an area of less than 5 km2. Despite temperatures sometimes reaching -15°C on the Somuncurá Plateau, both the ‘hot’ and ‘cold’ branches of the Valcheta stream never drop below 19°C. These isolated and unique thermal conditions have enabled the El Rincon stream frog to survive in such a hostile environment.

Until recently, little was known about the reproductive behaviour of the El Rincon stream frog. However, the establishment of a captive breeding population for conservation has provided insights into how this species reproduces. In captivity, this species exhibits scramble competition when breeding, which has not been observed in its closest relatives.

The greatest threats to this species are introduced trout, damming and livestock encroachment, with the latter degrading vital habitat and polluting the waters. The building of a dam appears to have also coincided with the loss of a subpopulation, suggesting this has been a major habitat disturbance. Invasive tree species, whose roots reach the springs and stream shores, are also associated with areas where the frogs are no longer found.

The range of the El Rincon stream frog is encompassed by the Somuncurá Provincial Reserve. Prior to 2012, there was limited management of this reserve, however since 2013 the Wild Plateau Initiative has been working on both in-situ and ex-situ efforts aimed at protecting this species and they have an agreement in place with the local protected area authorities. The conservation breeding programme has had success in breeding the species and has begun reintroductions to bolster the wild population.

  • Order: Anura
  • Family: Leptodactylidae
  • Population: Uncommon
  • Trend: decreasing
  • Size: 38mm

EDGE Score

EDGE Score: 5.9 (?)
ED Score: 21.86 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct


This species is found only from the headwaters of Arroyo Valcheta in Somuncurá Plateau, in the Rio Negro Province, Argentinean Patagonia at an altitudinal range of 500-800 metres above sea level.

Habitat and Ecology

This species is almost entirely aquatic, although it can surface and sit on rocks or vegetation within streams. Within the headwaters it can be found in shallow, slow-moving water and densely vegetated sections. The species breed via larval aquatic development where tadpoles will emerge from the eggs and be free living and then metamorphose after hatching.

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Conservation Actions

For each key category of conservation action, we calculated a conservation attention score based on expert information. In this graph, a higher score means the action is being carried out more intensively over more of the species range. The colour shows how important each action is considered to be for the conservation of this species.

Engaging stakeholders
Addressing threats
Status of knowledge
Management plan
Capacity building
Behaviour change
Awareness raising
  Score: 100 means the activity occurs at high level across more than 75% of the species range
Very Low

Overall Conservation Attention

We combined all of the expert information on conservation actions to calculate an overall conservation attention score for this species. Please help us to reach our goal of establishing dedicated conservation attention at “High” levels for all EDGE species.

Very Low Low Medium High

More information

Recent studies have grouped all possible conservation activities for any species into nine key categories (Washington et. al 2015). For each action, we asked experts for each species to assess the extent to which that action is being carried out and how much of the species’ range that action occurs in. For each action we used these two pieces of information to calculate the conservation attention score per action. A score of 100 means that the action is being carried out to a high level across at least 75% of the species range. We then combined the scores for all actions into an overall conservation attention score for the species. The experts also judged how important each category was to the conservation of that particular species.

This wordcloud illustrates the threats facing this species. The size of each word indicates the extent of a species range that is affected by that threat (larger size means a greater area is affected). The colour of the word indicates how much that threat impacts the species (darker shades of red mean the threat is more severe).

Livestock Dams Invasive species Invasive species Invasive species Agriculture

Threat wordcloud key:

Small area affected
Large area affected
Least severe
Most severe
Severity unknown
Source: The IUCN List of Threatened Species. Version 2017.1.
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Download the Survival Blueprint for this species below. Each survival blueprint is compiled by an EDGE Fellow working on the species with input from collaborators and stakeholders. The Survival Blueprint provides a status review (information on the distribution, protection status, habitat & ecology, threat and stakeholder analysis) and more information on the action programme listed here.

Vision (30-50 years)

The status of El Rincon-stream Frog has improved which is reflected in a lower threat category in the IUCN Red List and its absence in the list of the Top 100 EDGE amphibians worldwide. The subpopulations of this species (including several re-established sub-populations) are effectively protected and thriving in sanctuaries. All of these subpopulations are connected by corridors, free of threats, and supported by local community participation in the protection of native and endemic species in the stream, with the El Rincon-stream Frog as a flagship species. At least a half of its whole range is encompassed within a well-managed Protected Area in 40 years’ time.

Goal (5-10 years)

Ensure the long-lasting viability of El Rincon-stream Frog by recovering its metapopulation dynamics, which means at least ten viable subpopulations of frogs (of more than 350 individuals each), are connected by natural corridors and thriving in sanctuaries, with the engagement of the local community in this species’ conservation, reducing direct threats, by 10 years.


Improve breeding habitat by the creation and/or maintenance of ten breeding sanctuaries for frogs and establish a monitoring system to evaluate its success. Critical
Re-establish three extinct subpopulations of the El Rincon-stream Frog in the created sanctuaries and monitor their recovery and establishment. Critical
Connect seven sub-populations of El Rincon-stream Frog inhabiting the western branches of the headwaters of the Valcheta stream, by removing trout from 6 km downstream. Critical
Connect three sub-populations of El Rincon-stream Frog inhabiting the eastern branches of the headwaters of the Valcheta stream, by removing trout from 4 km downstream. Critical
Double the range of five extant subpopulations of the El Rincon-stream Frog by increasing available habitat. High
Creation of protected areas (at the national level) encompassing the habitats of the El Rincón stream frog. High
Engage local community in biodiversity conservation by promoting eco-tourism as an economic alternative to cattle ranching. Medium
Assess the genetical structure and identity of western and eastern subpopulations of El Rincon-stream Frog, to enhance further management that integrates inbreeding and/or outbreeding depression information into mitigation strategies. Medium
Assess the spatial ecology of this species, mainly the dispersal capacity as a way to enhance management aimed at improving connectivity among sub-populations. Medium
Build capacity among local stakeholders and protected area park rangers, to train local leaders to develop and conduct a monitoring programme for endangered species in the area. Medium
Build a network of environmental agencies and NGOs to foresee the protection of the NPA Meseta de Somuncura and its endemic species. Medium
Search in nearby areas to detect the presence of frogs. Medium

Tomás Martínez Aguirre

  • Project name: Towards the long-term conservation of the El Rincon Stream Frog (Pleurodema somuncurense)
  • Project site: Somuncura plateau, Rio Negro, Argentina
  • Active: 2018 - 2020
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