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88. 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.
Available at:

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 - ongoing
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