This species is only known from one locality at La Victoria, Departamento Nariño, in the Andes of southern Colombia, at an elevation of approximately 2,700 m asl (Coloma et al. 2010). This single site is considered to be one threat-defined location and its EOO is 6 km2.
Habitat and Ecology
Very little is known about its ecology. Gravid females were found in 1970 (Coloma et al. 2010), but details of reproduction or preferred macro- and micro-habitats remain unknown. However, based on information from other congeners, it is probable that it may reproduce by larval development. In addition, it is possible that this species may be a montane forest dweller given the surrounding habitat of its type locality.
It is currently known only from the type series, collected in 1970 (Coloma et al. 2010). The nearby area on the Ecuador side of the border was searched extensively in 2008, and the area of the type locality in Colombia has been searched regularly by the Universidad de Nariño during the 2010s, but did not record the species (Red List Assessment Workshop August 2016).
Agricultural encroachment could constitute a threat assuming that this species may be a habitat specialist, given that the type locality is now cultivated (see Coloma et al. 2010). In addition, chytrid fungus has been reported from a nearby area in northern Ecuador (Ron and Merino 2000 in Coloma et al. 2010) and could potentially also occur here. Coloma et al. (2010) cite the risk factor related to the threat of chytrid in Rödder et al. (2009:Fig. 2C) as being high in this species' area of distribution. Therefore, it is reasonable to presume that this species may have suffered a similar fate to that of many other high-altitude Atelopus species, namely a severe decline or possibly even extinction (Coloma et al. 2010).
This species has not been recorded in any protected areas.
Habitat protection is required.
Further surveys of high montane regions within southern Colombia and northern Ecuador are urgently required to determine if this species is still extant, and to see whether Bd is present.
Red List Status
Critically Endangered (CR)
Listed as Critically Endangered (Possibly Extinct) because, despite many searches in the 2010s, the species has not been seen since it was first collected in 1970. As such, it is presumed that the species suffered severe declines more than 10 years or three generations ago due to the spread of the chytrid fungus. It is therefore suspected to be Extinct and its population is inferred to be less than 50 mature individuals. In addition, its extent of occurrence (EOO) is 6 km2, it occurs in a single threat-defined location, and there is a continuing decline in the montane forest habitat of its type locality.
IUCN SSC Amphibian Specialist Group 2017. Atelopus gigas. The IUCN Red List of Threatened Species 2017: e.T18435526A56602058. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T18435526A56602058.en .Downloaded on 15 November 2018