This species is known from a few locations within close proximity in the Cauca Department, on the western slope of the central Andes, Totoro-Malvasa, in Colombia, between 2,820–3,250 m asl. It has also been reported from the Valle del Cauca Department (Cordoba et al. 2014), but the specimen needs detailed study to determine its taxonomic status. Its extent of occurrence (EOO) based on confirmed records is 165 km2.
Habitat and Ecology
This species occurs along streams on vegetation in páramo, and has not been recorded from disturbed habitat. Breeding and larval development takes place in streams.
There have been no records of this species since 2005 in the Laguna de San Rafael (Valencia and Lopez 2005). This area was searched intensively in 2014 for five days by three people without success (V. Plaza unpubl. data 2016). Two other historical localities, Gabriel López and Malvasá, were searched in 2015 and 2016 (visited by an average of four people for four days per month over five months), also without success. Due to this research, if the species persists, it does so in small numbers which is estimated to be fewer than 50 mature individuals. Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
This species is threatened by habitat loss caused by agricultural expansion (potato farming), water extraction, trout farming, and fumigation of potato crops. The 2004 assessment reported that chytridiomycosis was probably the major threat, leading to a catastrophic population decline. While there is currently no direct information confirming that chytrid has caused declines in this species in the 1990s, it is consistent with the pattern of decline in many other montane Atelopus species and therefore reasonable to infer that the disease might be the cause of declines in this species (Colombia Red List Assessment Workshop August 2016).
This species occurs in Puracé National Park.
Given the threat of chytridiomycosis, a captive-breeding programme might need to be established for this species.
More research into the species' range, ecological requirements, and population status is needed, and in particular surveys are needed to determine whether or not the species is currently in decline as has been evidenced in other high-elevation, stream-dwelling species of the genus in the region.
Red List Status
Critically Endangered (CR)
Atelopus eusebianus is listed as Critically Endangered because of a suspected population of less than 50 mature individuals. The historical range of the species has been exhaustively searched in recent years without recording a single individual (last record was in 2005). If a relict population persists, it consists of very few individuals.
IUCN SSC Amphibian Specialist Group 2017. Atelopus eusebianus. The IUCN Red List of Threatened Species 2017: e.T54507A49535373. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T54507A49535373.en .Downloaded on 23 January 2019