This species is known from Cerro Munchique, and Quintana (near Popayan in Cauca Department), between 2,100 and 2,350m asl, in Colombia.
Habitat and Ecology
It occurs on the ground next to streams in cloud forests. It lays its eggs on the ground, which (when hatched), are transported on the backs of the male to temporary ponds where they develop further. It has not been recorded outside forest habitat.
It is a common species.
The major threats are deforestation for agricultural development, the planting of illegal crops, logging, and human settlement.
The range of the species includes Parque Nacional Natural Munchique.
John Lynch, Fernando Castro 2004. Colostethus mertensi. In: IUCN 2014