This species is known from approximately 90–800 m Asl in eastern Thailand (Chan-ard 2003), eastern-central Lao PDR (Stuart 2005a), and northern to central Viet Nam (Ziegler and Köhler 2001, Stuart 2005b, Bain et al. 2007, Nguyen et al. 2009, Tran et al. 2010). These are unlikely to represent the actual limits of the species' range as similar habitat and elevations to those in the species' known localities extend into adjacent areas including northern Cambodia. 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. The species' EOO is 345,539 km2, which represents six threat-defined locations.
Habitat and Ecology
This species is associated with both lowland (Ziegler and Köhler 2001, Bain et al. 2007) and moderately montane (Stuart 2005a, Stuart 2005b, Tran et al. 2010) wet evergreen to mixed evergreen-deciduous forest. It has mostly been observed on rocks or foliage adjacent to streams (Ziegler and Köhler 2001, Stuart 2005a, Stuart 2005b, Bain et al. 2007, Tran et al. 2010), but is also known from karst environments and has been recorded in limestone caves within forest (Wildenhue et al. 2011). No observations of this species have occurred outside of either primary or secondary forest (Tao Nguyen, Truong Nguyen and J. Rowley pers. comm. March 2012). Amplexus has been observed at the beginning of the rainy season, and juveniles have been detected during the dry season (Ziegler and Köhler 2001). This species has been bred in captivity (Wildenhue et al. 2011); pairs amplexed and eggs were deposited in foam nests. In nature, such nests are presumably produced on leaves overhanging water, to which the larvae fall upon hatching as with other nest-building rhacophorid species.
Little is known about the size of this species' population except that it has been detected in a number of surveys (Ziegler and Köhler 2001, Chan-ard 2003, Stuart 2005a, Stuart 2005b, Bain et al. 2007, Tran et al. 2010), and described as locally abundant (Tao Nguyen, Truong Nguyen and J. Rowley pers. comm. March 2012). It is very likely that ongoing forest loss associated with expanding agriculture throughout this species' range (Meyfroidt and Lambin 2008, Sodhi et al. 2009, Meyfroidt et al. 2013) is causing some population declines. A captive population of the species exists at Leningrad Zoo, St. Petersburg, Russia (Wildenhues et al. 2011).
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). In the Central Highlands of Viet Nam this is a particularly pressing threat; large areas of forest are converted to agricultural land to grow cash crop plantations (e.g. rubber, coffee and tea) (Meyfroidt and Lambin 2008, Meyfroidt et al. 2013). High rates of deforestation for logging and agricultural encroachment on natural forest are also ongoing in much of Lao PDR and Cambodia (Sodhi et al. 2009). Given this species' apparent dependence on relatively undisturbed forest (Tao Nguyen, Truong Nguyen and J. Rowley pers. comm. March 2012), it is very likely threatened by habitat loss associated with these processes. It is possible that the species is collected for use in the international pet trade, however whether this is occurring at present and at levels that actually constitute a threat to its populations is unclear.
This species is known from a number of protected areas including Ke Go Nature Reserve and Phong Nha - Ke Bang National Park in Viet Nam (Ziegler and Köhler 2001) as well as Nakai-Nam Theun National Biodiversity Conservation Area in Lao PDR (Stuart 2005a). Other protected areas are included throughout this species' predicted range in Viet Nam, Lao PDR and Cambodia. It very likely occurs in some of these also.
Addressing the lack of data is the first step towards ensuring this species' long-term persistence; further research on its true distribution, threats, and the size and trends of its population would inform conservation decisions.
Red List Status
Least Concern (LC)
Listed as Least Concern as this species is relatively widespread, with an extent of occurrence (EOO) of 345539 km2, which represents six threat-defined locations.
IUCN SSC Amphibian Specialist Group 2017. Rhacophorus orlovi. The IUCN Red List of Threatened Species 2017: e.T59010A113960688. http://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T59010A113960688.en .Downloaded on 19 November 2018