Atelopus pachydermus is known from the Cordilleras de Tarros (at Cordillera Occidental) and Central of the Andes of northern Peru, departments of Cajamarca and Amazonas, and from Cordillera Oriental of the Andes in southern Ecuador, Province of Zamora Chinchipe, at about 2,600 m asl (Coloma et al. 2007).
Habitat and Ecology
Atelopus pachydermus occurs in areas that include humid montane forest and cloud forest (Coloma et al. 2007). It occurs near streams in páramo and sub-páramo, and breeding takes place in streams. The species requires a permanent source of water (L. Coloma pers. comm. 2008).
The current population status of Atelopus pachydermus in Peru is unknown. Fieldwork by the University of Kansas in February 1989 in the vicinity of Cutervo, Department of Cajamarca, revealed no Atelopus. Nonetheless, the most recent record is from 1994 or 1995, close to San Andrés caves in Cutervo National Park. The only record from Ecuador is from September 1985. Searches at the Ecuadorian locality were carried out on February and September 2001 and on April 2004; they revealed no Atelopus (Coloma et al. 2007).
The San Andrés caves, the general area where the species was found in Peru, are located in Parque Nacional Cutervo, which has 8,214 hectares of land protected by the Peruvian Government. In spite of its protected status, potato and artichoke field crops are located in the area of the Cutervo caves and there is extensive cattle ranching inside the park. Much of the humid forest on the Peruvian side of the species' distribution has been cleared and cultivated, and at higher elevation Eucalyptus has been planted. In Ecuador, in the proximities of the species' distribution, 2,000 hectares of forest and paramo habitats are protected within the Tapichalaca Reserve, which is located south of Podocarpus National Park (Coloma et al. 2007). Atelopus pachydermus occurs in an area close to the range of Atelopus peruensis, which disappeared in 1999/2000. Climate change and chytridiomycosis could be implicated in the species' disappearance (see Coloma et al. 2007).
The species was known to occur in Cutervo National Park (Peru) and Tapichalaca Reserve (Ecuador).
Atelopus pachydermus has been recently redescribed by Coloma et al. (2007). Atelopus pachydermus can be distinguished from other similar species by a combination of body size and different colour patterns (Coloma et al. 2007).
Luis A. Coloma 2008. Atelopus pachydermus. In: IUCN 2014