This species is currently known only from 600–620 m Asl at two localities in Phongsaly Province, northern Lao PDR (Stuart and Heatwole 2004) and Dien Bien Province, northern Viet Nam (Nguyen et al. 2014). These are unlikely to represent the actual limits of the species' range as similar habitat and elevations to those in its known localities extend into adjacent provinces of both Lao PDR and Viet Nam. Further surveys in these areas may uncover its presence there, therefore its range has been projected beyond known sites to include these areas of suitable habitat. This species' EOO is 16,109 km2, which consists of four threat-defined locations.
Habitat and Ecology
This species is associated with hilly evergreen forest mixed with bamboo, and has been observed in vegetation approximately 1 m above the ground (Stuart and Heatwole 2004, Nguyen et al. 2014). The species' reproductive biology is not known, however it may deposit its eggs in water-filled tree holes, as do many other Theloderma for which the reproductive strategy is known.
Nothing is currently known about the size of this species' population except that it is known from only two individuals, each detected in a separate survey (Stuart and Heatwole 2004, Nguyen et al. 2014). It is unclear whether this is due to true rarity or cryptic behaviour, and further research is needed to determine the species' true abundance. Deforestation continues to affect habitat in the species' range (Sodhi et al. 2009), and is very likely causing some declines.
Habitat loss and degradation due to the effects of rapidly expanding agriculture is an ongoing threat to biodiversity throughout Southeast Asia (Sodhi et al. 2009). Recent satellite imagery reveals areas of land cleared for agriculture throughout parts of this species' range. This species has only been observed in forest (Stuart and Heatwole 2004, Nguyen et al. 2014) and is very likely threatened by habitat loss.
All of this species' known localities are within protected areas; in Laos it is known from Phou Dendin National Biodiversity Conservation Area (Stuart and Heatwole 2004), and in Viet Nam it is known from Muong Nhe Nature Reserve (Nguyen et al. 2014).
Due to its presence in two protected areas and the need for additional information, no conservation recommendations can be made at this point. Therefore, addressing the lack of data is the first step towards ensuring this species' long-term persistence.
Further research on its true distribution, ecology, threats, and the size and trends of its population would inform conservation decisions.
Red List Status
Listed as Vulnerable as this species has an extent of occurrence (EOO) of only 16,109 km2, is known from four threat-defined locations, and is facing a continuing decline in the quality of parts of its habitat.
IUCN SSC Amphibian Specialist Group 2017. Theloderma petilum. The IUCN Red List of Threatened Species 2017: e.T61886A87451658. http://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T61886A87451658.en .Downloaded on 17 December 2018