This species is known from the double-peaked Mount Chontilla at 780 m asl, in the Iscozazin Valley, Pasco Region, from Serranía del Sira, Huánuco Region (Heyer 1994), and from Tingo Maria (651 m asl), Huánuco Region (A. Angulo pers. comm. 2017), in central Peru, east of the Andes. Although the species description lists its upper elevational range as 2,500 m asl, the 2009 El Sira Communal Reserve Master Plan indicates that the elevational range of the reserve oscillates around 2,000 m asl. Furthermore, the El Sira specimen was examined by Duellman and Toft (1979, as Leptodactylus wagneri), who determined its elevational range in this area to be 500–690 m asl. Thus, it is considered to occur between 500–780 m asl. Its extent of occurrence (EOO) is estimated to be 8,075 km2.
Habitat and Ecology
This species can be found on the forest floor of the Amazonian flanks of the Andes (Heyer 1994). It is thought to occur almost exclusively in closed forest habitats (Heyer 1994). While there are no direct data on this species, reproduction may take place in foam nests in temporary ponds.
This species is only known from the type series and museum specimens. Recent field surveys (September 2007 and May 2008) did not record this species in the vicinity of its type locality (J.C. Chaparro pers. comm. June 2010). An environmental impact assessment study conducted in Block 107 in both dry and rainy seasons also failed to record this species in Chontilla; however, it is possible that these latest surveys may have been conducted in the other peak of Chontilla. During February 2015, systematic nocturnal surveys were performed on the north-western slopes of the Sira: 1 hr 30 min surveys with two observers at each 100 m elevation, between 800 and 1,500 m asl (C. Beirne pers. comm. May 2016). In March 2015, five observers conducted surveys on the same ridge for four hours from 1,500–1,850 m asl (C. Beirne pers. comm. May 2016). In March 2016, two people searched for two hours at the highest peak on the ridge, between 1,800 and 1,925 m asl (C. Beirne pers. comm. May 2016). All searches were unsuccessful in detecting any individuals of this species; however it could be that these searches occurred above the elevational range of the species.
While the type locality (Chontilla) appears to be in a relatively good conservation status, some intervening areas in between the known localities are threatened by habitat loss due to increased agricultural activity, which is largely driven by government policies (land tenancy of the area is conditional upon converting forest to agricultural land). The Palcazú Valley is severely fragmented in its lower and mid-altitudinal reaches. The establishment of large livestock grazing areas is identified as the main mechanism of habitat fragmentation in the vicinity of Yanachaga Chemillén National Park. Illegal logging inside the Oxapampa-Asháninka-Yánesha Biosphere Reserve, as well as migratory agriculture and unsustainable use of agrochemicals are also threats (UNESCO 2016). Although the environmental impact assessment study of Block 107 did not record this species in 2008, the establishment of several oil concessions in the area could likely pose a threat to the remaining subpopulation (Larsen 2015), should it still be extant at this site.
This species can be found within the Yanesha Communal Reserve (Chontilla is within this reserve), and it might also occur in El Sira Communal Reserve, Parque Nacional Yanachaga Chemillén and Bosque de Protección San Matias San Carlos, although its presence at these protected areas needs to be verified. All of these conservation areas are within the Oxapampa-Asháninka-Yánesha Biosphere Reserve, established in 2010 (UNESCO 2010).
Enforcement is needed to curb the current and future threats to the Yanesha Communal Reserve.
Surveys in the appropriate elevational range are urgently needed to relocate this species at its known localities and in the intervening areas.
Red List Status
Listed as Data Deficient given the lack of recent information on its distribution, population status and threats in central Peru.
IUCN SSC Amphibian Specialist Group 2018. Leptodactylus pascoensis. The IUCN Red List of Threatened Species 2018: e.T57153A3056338. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T57153A3056338.en .Downloaded on 21 January 2019