This species occurs in a relatively narrow altitudinal band around 750-1,000m asl on the Pacific slope of the Sierra Madre del Sur in Guerrero and Oaxaca states, Mexico. Most specimens have been collected around the private hacienda of Agua del Obispo, along the old highway between Tierra Colorada and Chilpancingo, Guerrero. One other series is known from Putla de Guerrero, about 150km east on the same slope of the Sierra Madre del Sur, Oaxaca. The distribution is presumed to be continuous between these two localities at mid elevations, and might well continue further east or west as this region is undersampled for amphibians.
Habitat and Ecology
This species is known from the ecotone of scattered small pines and brush between lower altitude tropical deciduous forest and higher altitude pine-oak forest. The species is presumed to be a larval developer.
Field notes and collections by E.H. Taylor, H.M. Smith, and W.E. Duellman in the 1940s, 1950s and 1960s indicate that this species was common in the Agua del Obispo area. Approximately five weeks of fieldwork there during 2000 and 2003 resulted in the discovery of just a single individual, indicating a probable serious decline.
Although this species is believed to be tolerant of some degree of habitat alteration, such as selective logging, large-scale agricultural clearance and agrochemicals are likely to cause significant impacts. There is no direct evidence that chytridiomycosis is a threat to this species, but chytrid is known from this locality (Lips et al. 2004) and the drastic population decline is consistent with such an impact.
This species is not known from any protected areas, but might occur in the lower reaches of the Omilterne Reserve. There is a need for improved habitat protection at sites where this species is known to occur. Further research is required to investigate the potential threat posed by chytridiomycosis.
Red List Status
This species was removed from the synonymy of Incilius coccifer by Mendelson et al. (2005).
Joseph Mendelson 2006. Incilius cycladen. In: IUCN 2014