All known records of this species are from and restricted to the Ankarafa forest fragment on the Sahamalaza peninsula in northwest Madagascar, where it occurs in a single threat-defined location from 100-150 m asl (Penny et al. 2014). Forests on the Sahamalaza Peninsula occur in two regions (Anabohazo and Ankarafa), are separated by 20 km of regularly burned and grazed savanna and scrubland, and consist of habitat fragments; a third region (Analavory) has been all but destroyed by uncontrolled burning in 2004 (Penny et al. 2016). Surveys in other forest fragments in northwest Madagascar, e.g. in Sahamalaza, Manongarivo, Tsaratanana and Benavony, have failed to detect the species (Penny et al. 2014) so the limits of the species' distribution are unknown, but it is suspected to be restricted to the immediate area of the Ankarafa forest fragment. It has therefore been mapped to an approximate area of suitable habitat contiguous with known records and its extent of occurrence (EOO) is 61 km2.
Habitat and Ecology
This is an arboreal species known from intact lowland gallery forest, where it breeds in streams by larval development. It has not been found outside forest cover and it appears to be sensitive to anthropogenic disturbance (Penny et al. 2014). Calling and breeding activity are most intense during the first months of the rainy season (October-December) (Penny et al. 2014).
Over a transect of 3 km, an average of three specimens were collected per 200 metres of stream within the fragment (Penny et al. 2014). Due to ongoing habitat loss, the population is suspected to be decreasing.
A biosphere reserve has recently been designated in the area, but enforcement is lacking and forest is still under strong pressure from slash-and-burn (tavy) for small-holder agriculture, hardwood logging, and new and expanding human settlements (Penny et al. 2016). The greatest threat to amphibians on the Sahamalaza Peninsula remains, therefore, the destruction of forest habitat.
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).
The peninsula and coastal waters surrounding the species' range have recently been designated as the Réserve de la Biosphère du Sahamalaza-Iles Radama. Penny et al. (2016) noted that the Ankarafa Forest receives protection and contains a core protected zone, which seems to have halted farming activities.
The Action Plan for amphibians of the Sahamalaza Peninsula by Penny et al. (2016), calls for improved habitat protection inside the Reserve through the halting of human activity, especially detrimental agricultural practices, clear cutting of the forest, and even selective logging for hardwoods. This halt should be accompanied by education programmes to increase the awareness of amphibians and conservation benefits in local communities, improved community engagement (including employing local rangers to patrol protected areas), and alternative livelihoods. In addition, the Action Plan calls for the connectivity of suitable habitat to be increased through reforestation schemes.
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
Critically Endangered (CR)
All individuals are considered to occur within a single location and its extent of occurrence has been calculated as 61 km2. Given the ongoing destruction of suitable habitat, population declines can be expected to continue unless remedial action is taken, thus the species qualifies for the category Critically Endangered.
IUCN SSC Amphibian Specialist Group 2016. Boophis ankarafensis. The IUCN Red List of Threatened Species 2016: e.T68568328A68568331. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T68568328A68568331.en .Downloaded on 16 November 2018