This species is known from the region of Ranomafana National Park and Midongy Befotaka National Park (Bora et al., 2007) in southeastern Madagascar up to Anosibe an'Ala. Its extent of occurrence (EOO) is 26,736 km2 and it has been recorded between 600-1,200 m asl.
Habitat and Ecology
This species is a leaf-litter species that requires trees and streams. It is usually observed near streams and tiny trickles of water in rainforest, and males climb to call from vegetation about 1-2 m off the ground (Glaw and Vences, 2007). Has been found in agriculturally disturbed areas where there are streams with gallery forest (J. Riemann pers. comm., November 2014), as well as pristine forest (Ramamonjisoa and Rakotonoely, 2012) . Its reproductive mode is unknown - it could be by either direct or larval development.
It is a very common species. Due to ongoing decline in the quality and extent of its habitat, its population may be decreasing at a low rate.
This species' forest habitat is receding due to subsistence agriculture, timber extraction, charcoal manufacture, invasive spread of eucalyptus, livestock grazing and expanding human settlements. In Ranomafana, there is a threat from the increase in artisanal mining.
Species in this genus have tested positive for Batrachochytrium dendrobatidis (Bd), however currently there have been no negative effects observed within amphibian populations in Madagascar suggesting the Bd strain has a low virulence level (Bletz et al., 2015).
It occurs in Ranomafana National Park.
Conservation NeededResearch Needed
Improved protection and management of forests throughout the region is required, including within the boundaries of protected areas.
Further research is required to clarify the species' distribution, population size and trends, and is essential to fully understand the distribution, origin, type and virulence of Bd lineages found in Madagascar (Bletz et al., 2015).
Red List Status
Least Concern (LC)
Listed as Least Concern in view of its wide distribution and presumed large population.
A subpopulation similar to G. tschenki was found in the Ambodiriana Forest on the east coast of Madagascar, far north of the known range for this species; the identity of this population requires confirmation and this record is excluded for the purposes of this assessment (F. Glaw pers. comm. November 2015).
IUCN SSC Amphibian Specialist Group 2016. Gephyromantis tschenki. The IUCN Red List of Threatened Species 2016: e.T57529A67382718. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T57529A67382718.en .Downloaded on 20 February 2019