Taxonomic notes: Although there is a possibility that the newly rediscovered population from Peak Wilderness Sanctuary could comprise a new undescribed species, given uncertainty about the geographic provenance of Adenomus kandianus and the fact that the newly found population has morphological correspondence with this species, it is most parsimonious to consider that A. kandianus has been rediscovered (Wickramasinghe et al. 2012).

This species is endemic to Sri Lanka, and for the longest time was known only from the general type locality of "Ceylon" (= Sri Lanka). The scientific name appeared to suggest that it might have been collected in the vicinity of the city of Kandy, central Sri Lanka; however, all of the Central Province was referred to as Kandy in the late 19th century, when the species was described (Wickramasinghe et al. 2012). More recently, the species was rediscovered in the Peak Wilderness Sanctuary in Central Province, Sri Lanka, at 1,879 m asl (Wickramasinghe et al. 2012). The Sanctuary comprises 240 km², of which 211.75 km² comprise natural or semi-natural vegetation (Wickramasinghe et al. 2012). Its eastern boundary is adjacent to Horton Plains National Park (Wickramasinghe et al. 2012). While there is potential that this toad may have a more widespread occurrence within this area, it is so far only known from a single site and threat-defined location, in an area of 200 m² (Wickramasinghe et al. 2012), which is herein understood as its currently known extent of occurrence (EOO).

It was previously known only from two specimens (Wickramasinghe et al. 2012). There had been no sightings since the original description and the species was believed to be extinct (Manamendra-Arachchi and Pethiyagoda 1998), given that surveys in the the general area of Kandy turned up no new records. It was rediscovered in 2009, when close to 100 individuals were recorded over the course of a two-year study to document amphibian species richness across an elevational gradient (Wickramasinghe et al. 2012).

It has been found in montane cloud forest, with individuals encountered at night on rocks of river banks close to fast flowing streams (Wickramasinghe et al. 2012). It is sympatric with congener Adenomus dasi (Wickramasinghe et al. 2012). It is presumed to breed by larval development in water.

There are no reports of this species being utilized.

Pollution, particularly of streams, has been observed at the Peak Wilderness Sanctuary due to a very high volume of religious pilgrimage (Wickramasinghe et al. 2012). During pilgrimage season, which lasts about six months, there is a large accumulation of domestic waste and there is also exploitation of the forest (Wickramasinghe et al. 2012). In addition, there is illegal gem mining on river banks within the forest, and tea plantations in the surrounding areas are encroaching natural forests, so illegal tree felling to convert to tea plantations has become a major threat in the area (Wickramasinghe et al. 2012).

A stream at one of the pilgrimage sites, 'Seethagagula', has been blocked in one place by a private company, and the water has been diverted to an artificial tank to facilitate a place for bathing for the pilgrims (M. Wickramasinghe pers. comm. June 2012). Additionally, during the wet season, species such as the Stone Sucker (Garra ceylonensis) travel upstream, and by blocking the stream in several places this has created a barrier for the breeding of these and other aquatic species (M. Wickramasinghe pers. comm. June 2012). Should A. kandianus be a stream breeder (as suspected), this could potentially impact this toad's breeding biology. Downstream from this site large amounts of domestic chemicals (e.g., shampoo) are being disposed of in the stream, and it is suspected that this could negatively impact amphibian populations given that large aggregations of tadpoles (not A. kandianus) were observed at higher elevations of the same stream, but in areas below the polluted site low densities or no individuals were observed (M. Wickramasinghe pers. comm. June 2012). Furthermore, during the dry season the reduced volume of water in the stream may lead to greater concentrations of chemicals in the breeding pools (M. Wickramasinghe pers. comm. June 2012). Invasive plant species are also suspected of causing changes to the understory and canopy cover of the area (M. Wickramasinghe pers. comm. June 2012).

• 9.4 Garbage & solid waste
• 2.1.4 Scale Unknown/Unrecorded
• 3.2 Mining & quarrying
• 5.3.1 Intentional use: (subsistence/small scale) [harvest]
• 6.1 Recreational activities
• 6.3 Work & other activities
• 7.2.11 Dams (size unknown)
• 8.1.1 Unspecified species
• 9.1.2 Run-off

Although this toad is found within the Peak Wilderness Sanctuary, which has been declared part of the Central Hills World Heritage Sites, its habitat is under severe human pressure (Wickramasinghe et al. 2012). Better site and resource management are urgently needed to protect the only known site where this toad is known to occur. More information is needed on this species' distribution, population status and natural history, as well as the potential effects of some of its additional suspected threats.

• 2.1 Site/area management

Listed as Critically Endangered given that it is known from a single site and threat-defined location, with an Extent of Occurrence estimated to be 200 m², and a continuing decline of its natural habitat in the Peak Wilderness Sanctuary of Central Province, Sri Lanka.

• Günther, A. 1872. Descriptions of some Ceylonese Reptiles and Batrachians. Annales and Magazine of Natural History: 85-88.
• Manamendra-Arachchi, K. and Pethiyagoda, R. 1998. A synopsis of the Sri Lankan Bufonidae (Amphibia: Anura), with description of two new species. Journal of South Asian Natural History: 213-246.
• Wickramasinghe, L.J.M., Vidanapathirana, D.R., and Wickramasinghe, N. 2012. Back from the dead: The world’s rarest toad Adenomus kandianus rediscovered in Sri Lanka. Zootaxa: 63-68.