|Scientific Name:||Boophis williamsi (Guibé, 1974)|
Rhacophorus williamsi Guibé, 1974
|Taxonomic Source(s):||Frost, D.R. 2015. Amphibian Species of the World: an Online Reference. Version 6.0. New York, USA. Available at: http://research.amnh.org/herpetology/amphibia/index.html.|
|Red List Category & Criteria:||Critically Endangered B1ab(iii)+2ab(iii) ver 3.1|
|Assessor(s):||IUCN SSC Amphibian Specialist Group|
|Contributor(s):||Crottini, A., Glaw, F., Scherz, D., Vences, M. & Nussbaum, R.|
|Facilitator/Compiler(s):||Luedtke, J. & Hobin, L.|
Listed as Critically Endangered because its extent of occurrence is 19 km2, its area of occupancy is estimated to be less than 10 km2, all individuals are in a single threat-defined location, and there is continuing decline in the extent and quality of its habitat at Ankaratra.
|Previously published Red List assessments:|
|Range Description:||This species has been recorded from Ambohimirandrana at 2,100 m asl and Tsimiaramianadahy at 2,381 m on Tsiafajavona Mountain in central Madagascar. This is an isolated peak in the Ankaratra Massif, its summit being at 2,642 m asl, making it the second highest in Madagascar and the species may occur higher up on this mountain and at other high-altitude localities within the Massif. As such, the range map includes the approximate limits of Tsiafajavona, the locality of the predation event on this species recorded at Tsimiaramianadahy by Ndriantsoa et al. (2014), and the sites at which the species was recorded by Andreone et al. (2014). Its extent of occurrence (EOO) is 19 km2 representing a single threat-defined location.|
|Range Map:||Click here to open the map viewer and explore range.|
Its population is undoubtedly small, since the species is highly localized. At one locality (Ambohimirandra 1) the population size was estimated at only 46 individuals through mark-recapture (Andreone et al. 2014). Due to ongoing declines in the extent and quality of habitat the population is suspected to be decreasing.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||The species is a montane stream micro-endemic, lives and breeds in fast-flowing streams and has a maximum longevity of six years (Andreone et al. 2014). The Ankaratra Massif "harbours residual threatened montane rainforest fragments, high-altitude savanna and heathland" (Vences et al. 2002 in Andreone et al. 2014) and the species has been recorded from streams in open heathland habitat, forest, and forest with cleared areas (Andreone et al. 2014).|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Movement patterns:||Not a Migrant|
|Use and Trade:||There are no records of this species being utilized.|
One of the most threatened amphibians in Madagascar, it lives in a severely degraded area where its habitat is under constant threat from fire (it is burned annually and an arson event swept through part of its range in 2009), illegal logging, overgrazing by livestock, and expanding potato farming. It might also be threatened by the impacts of pollution and siltation of its breeding streams. As a mountain-top species, it is also potentially at risk from climate change.
A single predation event of this species by Boophis goudotii has been recorded at Tsimiaramianadahy, although it is not conclusive that this species is a regular component of B. goudotii diet and further studies should be carried out (Ndriantsoa et al. 2014).
Furthermore, a few individuals tested positive for Batrachochytrium dendrobatidis (Bd), but there have been no negative effects or mass mortality events related to Bd within amphibian populations in Madagascar, suggesting the Bd strain has a low virulence level (Bletz et al. 2015). Samples from this species from 2010 all tested negative for Bd (Andreone et al. 2014).
The Ankarana Massif Reserve was established by the Madagascan conservation organization Association Vondrona Ivon’ny Fampandrosoanavif (VIF) and with the support of its U.S. partners Amphibian Survival Alliance, Global Wildlife Conservation and Rainforest Trust (Moore 2015). VIF manage the reserve through forest guard units assembled in collaboration with local communities. These units regularly patrol the reserve to stop illegal logging and have effectively decreased logging rates. In addition, local communities are engaged in reforestation efforts intended to improve habitat within the Reserve and amphibian populations on the Massif are subject to ongoing monitoring (A. Crottini pers. comm. February 2016).
Protection of remaining habitat (including important streams) on the Ankaratra Massif is urgently needed. The species has been assessed through Amphibian Ark's Conservation Needs Assessment as being in need of Rescue, In Situ Research, and Biobanking efforts (ASG Madagascar 2015) and Andreone et al. (2014) recommend developing "species-specific know-how" regarding its captive breeding.
Further work is needed to better understand the species life history and determine whether or not the species might survive elsewhere on the Massif. Further research is also essential to fully understand the distribution, origin, type and virulence of Bd lineages found in Madagascar (Bletz et al. 2015). A better understanding of its natural history will also yield information about the potential interactions and ecological relationship between this species and Boophis goudotii (Ndriantsoa et al. 2014).
|Citation:||IUCN SSC Amphibian Specialist Group. 2016. Boophis williamsi. The IUCN Red List of Threatened Species 2016: e.T57435A84165560.Downloaded on 15 August 2018.|
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