This species was previously only known from its type locality of Mehuin, Valdivia Province, Chile. It is now known to occur from Colehual Alto to Cordillera Pelada, between 50–1,100 m asl (C. Cuevas pers. comm. July 2015), and has recently been recorded from Llancahue ca 10 km southeast of Valdivia city (Parada et al. 2017) and in Alerce Costero National Park at 700 m asl (Silva 2017). It occurs in six geographical localities within Valdivia Province, Chile (C. Cuevas pers. comm. July 2015). Its extent of occurrence (EOO) is 1,323 km2.
Habitat and Ecology
This species occurs in small streams and under flat stones in temperate forest. At night, it feeds on the margins of streams. Breeding takes place in water, and the species is characterized by free-swimming tadpoles. It is not considered to be tolerant to water pollution (C. Cuevas and C. Castro pers. comm. July 2015).
It is locally common and was collected during surveys in 2014 (C. Cuevas pers. comm. July 2015). The subpopulation of Chanchán, which appears to have been common in the past, is threatened from logging for firewood and cattle, and it is possible that it may be extirpated in the future (F. Rabanal and C. Cuevas pers. comm. July 2015). It is considered to be severely fragmented (C. Cuevas pers. comm. July 2015) and, due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
The major threat is habitat loss as a result of clear-cutting of native forest for tree plantations (C. Cuevas pers. comm. July 2015) and cattle farming. Human-induced fires (C. Castro pers. comm. July 2015) and the construction of the coastal highway are also threats (C. Cuevas pers. comm. July 2015). It is not considered to be tolerant to water pollution (C. Cuevas and C. Castro pers. comm. July 2015). In Alerce Costero National Park, this species was found along a trail that is frequently used by crowds of people who bathe in the nearby stream, using soap and other chemical compounds which are likely to be harmful to any amphibians and tadpoles found there (Silva 2017).
This species occurs in Alerce Costero National Park.
There is a need for improved protection and maintenance of the Valdivian temperate forests in its range.
The population status of this species in Chanchán should be closely monitored.
Red List Status
Critically Endangered (CR)
Listed as Endangered because its extent of occurrence (EOO) is 1,323 km2, its population considered to be severely fragmented, there is continuing decline in the extent and quality of its habitat and number of mature individuals, and the projected loss of the subpopulation in Chanchán, all in Valdivia Province, Chile.
IUCN SSC Amphibian Specialist Group 2018. Insuetophrynus acarpicus. The IUCN Red List of Threatened Species 2018: e.T10832A79809262. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T10832A79809262.en .Downloaded on 19 February 2019