On 19 April 2017, during a routine inspection in the Laguna Colorada region of the National Reserve of Andean Fauna “Eduardo Avaroa” (the specific locality is not be identified for security reasons), ED, alerted by animal calls, discovered a burrow under a large boulder. With local help he excavated the burrow and found four short-tailed chinchillas Chinchilla chinchilla of different ages and sexes; two additional individuals were discovered inside the den the next day. All individuals were returned to their burrow 3 days later after measurements and photographs had been taken.

This chinchilla is one of two species native to the Andes. The last verified report of the presence of the short-tailed chinchilla in Bolivia dates from 1939 (S. Anderson, 1997, Mammals of Bolivia, Bulletin of the American Museum of Natural History, 231, 1–652). For this reason, it was thought to be the first Bolivian mammal to have gone extinct in the wild, but it was later recategorized as Critically Endangered (T. Tarifa, 2009, Chinchilla chinchilla, In Libro rojo de la fauna silvestre de vertebrados de Bolivia, pp. 457–459, Ministerio de Medio Ambiente y Agua, La Paz, Bolivia) based on undocumented reports by residents of peasant communities in the southern department of Potosí. Fieldwork across the highlands of Bolivia failed, however, to verify the occurrence of the species.

Overexploitation of wild chinchilla populations for their valuable pelts in the 19th and early 20th century is thought to have been the main cause of the decline of this species across its former range. The species is categorized as Endangered on the IUCN Red List. Historically broadly distributed, chinchillas inhabited the coast and the Andes of central Peru to the south through the high Andean regions of central-west Bolivia, northern Chile, and north-west Argentina. It was recently rediscovered in northern Chile (P. Valladares et al., 2014, Animal Biodiversity and Conservation, 37, 89–93). Although the chinchilla was previously considered extinct in Peru, there is potentially an extant population in the remote central highlands (A. Spotorno & J. Patton, 2015, Superfamily Chinchilloidea Bennet, 1833. In Mammals of South America, Volume 2 Rodents, eds J.L. Patton et al., pp. 762–783, The University of Chicago Press, USA).

The National Reserve of Andean Fauna “Eduardo Avaroa” is a flagship conservation unit of the Bolivian National Park system, covering the dry Puna region of southern Bolivia. The fauna of the Reserve is characterized by species adapted to the extreme conditions of the region, including the Endangered Andean mountain cat Leopardus jacobita and Vulnerable Andean Flamingo Phoenicoparrus andinus. These species and habitats are under increasing threats from tourism and climate change.

The current management plan of the Reserve does not include provisions to protect the newly found population of chinchillas and there is an urgent need to include stakeholders and policy makers in development of a long-term plan for the protection of this unique fauna, of which chinchillas are a major component. Initial contacts towards this goal are ongoing.