This species is known from four threat-defined locations in Colombia: (1) the slopes of southeast Cuchilla de San Lorenzo, in the northwest sector of Parque Nacional Natural Sierra Nevada de Santa Marta (in the department of Magdalena), and the adjacent El Dorado Nature Reserve, (2) in La Serranía de Cebolletas, in the department of Magdalena, (3) an area near Nabusimake in the department of Cesar, and (4) in the Rio Ranchería watershed in the department of La Guajira (L.A. Rueda-Solano pers comm. 2014). These locations are geographically isolated and separated by high mountain formations; the threat of habitat loss is driven by local factors and differs in intensity among these sites. It has been recorded from 1,900-2,800 m asl. Its extent of occurrence (EOO) is estimated to be 2,992 km2.
Habitat and Ecology
This species is an inhabitant of sub-Andean forests and can also tolerate some degree of habitat disturbance. Individuals have been found within a closed-canopy (up to 25 m) secondary forest and in riparian forest, close to a creek (Carvajalino-Fernández et al. 2008). The species lays egg chains in streams, where the tadpoles also develop.
This was a common species when it was sampled in 1992. It was rediscovered in 2006, following survey work in the recently established El Dorado Nature Reserve. Further field work reported on the apparent health of the subpopulation at San Lorenzo (26 individuals recorded in the span of two days in 2006, observations on reproductive activities and recruitment; Carvajalino-Fernández et al. 2008). Sampling efforts on four separate occasions in 2006 and 2007 provided additional records from Sierra Nevada de Santa Marta, with 31 individuals observed at two sites (Granda-Rodríguez et al. 2012). Another survey in 2009 found that individuals of the species, particularly juveniles, were locally abundant along a stretch of the Rio Gaira in San Lorenzo (L.A. Rueda-Solano pers. comm. 2014). In 2014, a survey of one kilometre of stream in San Lorenzo produced observations of three individuals (O. Cortés pers. comm. 2014). In general, individuals appear to aggregate only in a few specific stream reaches at each site and are absent from nearby suitable habitat.
Chytridiomycosis has had a devastating impact on other high-altitude species of Atelopus and represents a plausible threat for this species; however, infections have not been detected in Sierra Nevada de Santa Marta (L.A. Rueda-Solano pers. comm. 2014). Other major threats include habitat loss caused by agriculture (illegal crops) and logging, and pollution caused by the fumigation of illegal crops. Specifically, the subpopulation in La Serranía de Cebolletas is threatened by ongoing conversion of forest to pasture lands (L.A. Rueda-Solano pers. comm. 2014), and there is forest loss occurring in San Lorenzo near the El Dorado Reserve (O. Cortés pers. comm. 2014).
The range of this species encompasses the Parque Nacional Natural Sierra Nevada de Santa Marta and the adjacent El Dorado Nature Reserve. El Dorado Reserve was established in March 2006 to secure one of the last forested valleys for this and other threatened amphibian and bird species (Fundación ProAves 2006). Additional habitat protection is needed at La Serranía de Cebolletas. Ongoing surveys are needed to monitor the current population status, and disease screening is needed given the potential threat of a chytridiomycosis outbreak.
Red List Status
Listed as Endangered because its extent of occurrence (EOO) is estimated to be 2,992 km2, it is considered to occur in four threat-defined locations, and there is continuing decline in the area, extent, and quality of its habitat in northern Colombia. There is lack of evidence for ongoing population declines or sufficient reason to suspect precipitous declines will occur in the near future. However, the threat of chytrid being introduced to the area warrants close monitoring of known subpopulations for infection.
IUCN SSC Amphibian Specialist Group 2014. Atelopus nahumae. The IUCN Red List of Threatened Species 2014: e.T54531A3015954. http://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T54531A3015954.en .Downloaded on 23 January 2019