Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Rhacophoridae

Scientific Name: Rhacophorus helenae
Species Authority: Rowley, Tran, Hoang & Le 2012
Taxonomic Source(s): Frost, D.R. 2014. Amphibian Species of the World: an Online Reference. Version 6 (27 January 2014). New York, USA. Available at: (Accessed: 27 January 2014).

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(i,iii,iv) ver 3.1
Year Published: 2014
Date Assessed: 2014-01-28
Assessor(s): IUCN SSC Amphibian Specialist Group
Reviewer(s): Stuart, S.N.
Contributor(s): Rowley, J. L., Tran, D. & Le, D.
Facilitator/Compiler(s): Rowley, J. L. & Cutajar, T.
Listed as Endangered because of ongoing habitat loss resulting in a dramatic decrease from estimated historical distribution, resulting in a currently estimated extent of occurrence of only 308 km2. The species is only known from two threat-defined locations separated by agricultural land - both of which are under continued threat from habitat loss and modification - and is therefore severely fragmented.

Geographic Range [top]

Range Description: This species is known from two patches of forest in Binh Thuan and Dong Nai Provinces in southern Viet Nam. The two known localities are approximately 30 km apart and are isolated from each other by agricultural land (Rowley et al. 2012). Both localities are threatened by encroachment of agriculture and harvesting of forest resources, thus the species is thought to occur in two threat-defined locations, which are estimated to be declining. The species is only known from low-elevation forests between approximately 85-158 m Asl (Rowley et al. 2012). Its range, taken as a proxy for extent of occurrence, has been estimated at 308 km2 and has been observed to be in decline. It is possible that its range extends into other fragments of lowland forests in southern Viet Nam and into extreme eastern Cambodia, but amphibian surveys in these areas have been carried out and no large, green rhacophorids have been recorded (Rowley et al. 2012).
Countries occurrence:
Viet Nam
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): Unknown
Estimated extent of occurrence (EOO) - km2: 308
Continuing decline in extent of occurrence (EOO): Yes
Extreme fluctuations in extent of occurrence (EOO): Unknown
Number of Locations: 2
Continuing decline in number of locations: Yes
Lower elevation limit (metres): 85
Upper elevation limit (metres): 158
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: There is very little data on the population size of the species. Only five individuals have ever been seen, despite several weeks of amphibian surveys in both localities (Rowley et al. 2012). The true population size of the species may be difficult to determine due to its arboreal nature (Rowley et al. 2012), however it is suspected to be severely fragmented, with only two subpopulations known (Rowley et al. 2012).
Current Population Trend: Unknown
Additional data:
Continuing decline of mature individuals: Unknown
Extreme fluctuations: Unknown Population severely fragmented: Yes
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: Unknown All individuals in one subpopulation: Unknown

Habitat and Ecology [top]

Habitat and Ecology: The species is found in small, fragmented areas of mixed lowland forest. There is a high human population density in the area and the forest is highly disturbed and increasingly fragmented. Pairs in amplexus and foam nests above temporary pools on the forest floor have been recorded during September (Rowley et al. 2012). Tadpoles presumably drop into pools upon hatching, as occurs in related species.
Systems: Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat: Yes

Use and Trade [top]

Use and Trade: The species is likely to be collected for the international pet trade as related species (eg. Rhacophorus kio) are currently in the pet trade.

Threats [top]

Major Threat(s): The continued survival of the species is threatened by further habitat loss and degradation due to encroachment (eg. livestock grazing and collection of forest products), and habitat isolation (Rowley et al. 2012). Collection for the pet trade is also a concern.

Conservation Actions [top]

Conservation Actions: The species is known from two relatively small and isolated protected areas: Nui Ong Nature Reserve and Tan Phu Forest (Rowley et al. 2012). Addressing the lack of data is the first step towards ensuring the species' conservation, thus research is needed on the species' population status, its life history and ecology, harvest levels, and potential threats. Monitoring is required to understand population trends and habitat requirements. It may also be prudent to explore strategies for increasing the level of habitat protection in its known range.

Citation: IUCN SSC Amphibian Specialist Group. 2014. Rhacophorus helenae. The IUCN Red List of Threatened Species 2014: e.T47144519A47144530. . Downloaded on 05 October 2015.
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