This species ranges from southwestern Costa Rica (a single locality) and adjacent western Panama (1,050-1,600m), through eastern Panama in lowland and premontane zones (200-860m) to the Pacific coast of western Colombia, south to Valle de Cauca Department (up to 800m in Colombia).
Habitat and Ecology
It is a terrestrial and diurnal species of humid lowland, premontane and montane forest. Adults may be encountered along rocky sections of forest streams. It can occur in secondary forest and plantation forests, and occurs in degraded habitats in Colombia. The eggs are deposited in the leaf-litter and the males transport hatching tadpoles to forest streams to complete metamorphosis.
It remains widespread in the Choco of Colombia (Taran Grant pers. comm. 2007). It was formerly recorded at a single Costa Rica locality, Las Cruces (observed in 2002), but and has recently been found in the San Vito area (Federico Bolaños pers. comm. 2007). It was formerly common in Panama, and while it is still present in Cerro Campana and eastern Panama (Roberto Ibáñez pers. comm. 2007) it has significantly declined in western Panama and is now absent from Fortuna, Santa Fe and El Cope (Karen Lips pers. comm.).
Declines in this species within the western part of the range are associated with the disease chytridiomycosis. Lips et al. (2006) report that 48 dead Colostethus nubicola (infected with the chytrid fungus Batrachochytrium dendrobatidis) were recorded at El Cope in 2004. It is probably also affected by general habitat loss in Panama through deforestation. It is not generally considered to be threatened in Colombia at present.
It is present in several protected areas in Colombia, and in more than twelve protected areas in Panama, as well as in a single protected area in Costa Rica. There is an urgent need to complete the taxonomic revision of the Colostethus nubicola species complex. Following a clarification of the taxonomic status of this group, it may be necessary to develop ex-situ insurance colonies for remaining western populations.
Red List Status
Near Threatened (NT)
Listed as Near Threatened, because this species is in significant decline in the western parts of its range, but has probably globally declined at a rate of less than 30% over ten years (largely associated with the disease chytridiomycosis), thus making the species close to qualifying for Vulnerable. It seems probable that population declines in this species will continue into the east of the species range, whereby it may meet the Red List Criteria for Vulnerable or possibly Endangered during the next global assessment.
At present, Silverstoneia nubicola is considered to be a complex of several taxa. It is currently undergoing taxonomic revision (Taran Grant pers. comm.).
Bolaños, F., Ibáñez, R., Chaves, G., Savage, J., Jaramillo, C., Fuenmayor, Q., Grant, T., Lötters, S. & Lips, K. 2008. Silverstoneia nubicola. The IUCN Red List of Threatened Species 2008: e.T55121A11254911. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T55121A11254911.en