This species is restricted to rainforest in eastern Madagascar where it has only been recorded at a single site in the area around Lake Alaotra at 1,032m asl (Vieites et al. 2012). The range is unlikely to extend further south than the limits of congeners Gephyromantis thelenae and G. eiselti; the northern limits of its range are unknown. However, its range has been mapped to the forest fragment in which it was found, which results in an extent of occurrence of 10 km2.
Habitat and Ecology
This species, like those closely related to it (G. eiseti and G.thelenae), inhabits rainforest and is typically found away from bodies of water (Vieites et al. 2012). It has been observed in highly disturbed rainforest perching in the dense vegetation and shrubs that were surrounding a fallen tree, and has been heard calling during the day and at dusk (Vieites et al. 2012). Its breeding is unknown, but it is possibly by direct development, since the species appears not to be associated with waterbodies.
Little is known about this species population, but a chorus of three or four individuals were heard from a single site of the Mahasoa forest when it was surveyed (Vieites et al., 2012). Its population is suspected to be decreasing due to ongoing deforestation around lake Alaotra and across the rainforests of eastern Madagascar.
Lake Alaotra is surrounded by rice cultivation and as a result the nearby forest is under a high amount of pressure and has been heavily degraded. If logging continues at current rates the habitat at this species' type locality may disappear altogether (Vieites et al., 2012)
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 is currently not known to occur in any protected areas.
Efforts to reduce deforestation around Lake Alaotra and the rest of Madagascar's eastern rainforest are necessary.
Further research is required to clarify the species' distribution, population size and trends, and it is essential to fully understand the distribution, origin, type and virulence of Bd lineages found in Madagascar (Bletz et al., 2015).
Red List Status
Critically Endangered (CR)
Listed as Critically Endangered because it is only known from a single forest fragment of which the extent of occurrence is 10km2 and which constitutes a single threat-defined location. Furthermore, the ongoing decline in the quality and extent of its rainforest habitat near Lake Alaotra is particularly severe, and these declines are also taking place throughout the eastern rainforests of Madagascar.
Closely related to Gephyromantis eiselti and Gephyromantis thelenae according to the original publication (Frost 2013).
IUCN SSC Amphibian Specialist Group 2016. Gephyromantis mafy. The IUCN Red List of Threatened Species 2016: e.T49563555A49563617. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T49563555A49563617.en