Assessment Results
Raorchestes signatus
Cross-backed Bush Frog, Boulenger's Bubble-nest Frog
Order:
Anura
Family:
Rhacophoridae
Synonym(s):
Ixalus signatus, Philautus signatus, Pseudophilautus signatus
Assessed for:
India
on:
13 Nov 2020
by:
AArk/ASG India Assessment Workshop
Authors:
Nikhil Modak, Rajkumar K.P., S.R. Ganesh and S.R. Chandramouli
IUCN Global Red List:
Endangered (EN)
National Red List:
(not assessed)
Distribution:
India
Evolutionary Distinctiveness score:
14.37782128
Recommended Conservation Actions:
Additional Comments:
| Question # | Short Name | Question Text | Response | Comments |
| 1 | Extinction risk | Current IUCN Red List category. [Data obtained from the IUCN Red List.] | Endangered (EN) | Listed as Endangered because its extent of occurrence (EOO) is 1,014 km2, it occurs in five or fewer threat-defined locations, and there is continuing decline in the extent and quality of its habitat. |
| 2 | Possibly extinct | Is there a strong possibility that this species might be extinct in the wild? | No / unlikely | |
| 3 | Phylogenetic significance | The taxon’s Evolutionary Distinctiveness (ED) score, as generated by the ZSL EDGE program. (These data are not editable by Assessors). | ED value < 20 | |
| 4 | Protected habitat | Is a population of at least 50% of the individuals of the taxon included within a well-managed or reliably protected area or areas? | Yes / probably | This bush frog occurs in the Nilgiri Hills of southern Western Ghats in Tamil Nadu State, India, and surrounding areas in Coonoor, Kothagiri, Naduvattam, Avalanche, Parsons Valley (Biju and Bossuyt 2009), Udhagamandalam (Princy and Kannan 2015), Ooty, Emerald, and Mukurthi National Park (Princy et al. 2017, Siva 2020). It has also been recorded from Silent Valley National Park in Kerala (Rajkumar K.P., pers. comm. October 2020). It is restricted to its known range (S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). It ranges between 1,780-2,465 m (Bossuyt and Dubois 2001, Biju and Bossuyt 2009, Princy et al. 2017, Siva 2020). |
| 5 | Habitat for reintroduction, conservation translocation or supplementation | Does enough well-managed and reliably protected habitat exist, either within or outside of currently protected areas that is suitable for conservation translocation, including population restoration or conservation introduction? | Yes / probably | Nilgiri Hills at Mukurthi National Park. |
| 6 | Previous reintroductions | Have reintroduction or translocation attempts been made in the past for this species? | No | |
| 7 | In situ conservation activities | Are any in situ conservation actions currently in place for this species? (Only required if a Red List Assessment has not been completed, or if new actions have been implemented since the last Red List Assessment. (Information from the Conservation Actions section of the Red List assessment should be reviewed and considered when answering this question.). | Yes / probably | It has been recorded from the Nilgiri Biosphere Reserve. |
| 8 | In situ conservation activities | Are additional in situ conservation actions required to help conserve this species in the wild (e.g. habitat restoration and/or protection, control of invasive species, national legislation etc.)? | Yes / probably | Improved habitat protection is required, as well as the education of tourists on their disturbance behaviours which would also be beneficial for this species (S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). Other recommended conservation measures are to implement a long term management project, research on the impact of pesticides at the subpopulation level, and public awareness programs to prevent killing (Princy and Kannan 2015). |
| 9 | In situ research | Is additional in situ research required to better understand the species, e.g. distribution, population trends, natural history etc.? | Yes | Deformities and malformations has been seen in this species, so understanding the cause is important (in some other parts of the world this has been attributed to Bd infection) (S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). Population monitoring is also recommended (India Red List/CNA Assessment Workshop October 2020). |
| 10 | Threat mitigation | Are the threats facing the taxon, including any new and emerging threats not considered in the IUCN Red List, potentially reversible? | Threats unlikely to be reversed in time to prevent further decline / extinction | This is an arboreal species associated with tropical moist evergreen montane forest, although it can occur in modified areas. It inhabits shola vegetation, moss-covered earthen banks inside forest patches (Biju and Bossuyt 2009, Siva 2020), human habitations, tea plantations and grassland (Princy et al.2017). It is considered to tolerate a degree of anthropogenic disturbance but is elevational dependent (S.R. Ganesh, pers. comm. November 2020). Despite being a fairly adaptable species, the major threat is the conversion of native forest to intensively cultivated areas (including timber and non-timber plantations), and the associated pollution from pesticides and herbicides, which affect its ability to reproduce (Princy and Kannan 2015, S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). Tourism is considered to be a major threat throughout its range and is causing species disturbance, vehicular noise is interfering with their calling behaviour, and plastic pollution is a problem for its habitat (S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). In Mukurthi National Park, the creation of fire lines is also a threat to the species and its habitat (S.R. Ganesh, pers. comm. November 2020). In the Nilgiri Hills, the temperature has increased in the last decade which has affected the shola forest habitat and allowed the encroachment of invasive plant plantations (eucalyptus, lantana, acacia,wattle, pinewoods) which has reduced the level of the water table, as well as causing changes in the rainfall patterns (S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). Climate change is also a likely future threat which could cause habitat shifting, and subpopulations that already exist in higher elevations may be lost as they have no habitat to migrate to. Deformities and malformations have been recorded due to causes that are unknown at present, although are similar to cases in other species in different regions of the world that are caused by increased UV levels (S.R. Ganesh and S.R Chandramouli, pers. comm. November 2020). Batrachochytrium dendrobatidis (Bd) has been found in other species of the genus, so chytridiomycosis may be a potential threat for this species but further research is required (India RLA/CNA workshop, November 2020). |
| 11 | Over-collection from the wild | Is the taxon suffering from collection within its natural range, either for food, for the pet trade or for any other reason, which threatens the species’ continued persistence in the wild? | No / unlikely | |
| 12 | Population recovery | Is the known population of this species in the wild large enough to recover naturally, without ex situ intervention if threats are mitigated? | Yes / probably | It is commonly seen in the Nilgiri Hills (Bossuyt and Dubois 2001) and is common throughout its range, but is believed to be declining. |
| 13 | Action plans | Does an Action Plan for the species already exist, or is one currently being developed? | No | |
| 14 | Biological distinctiveness | Does the taxon exhibit a distinctive reproductive mode, behaviour, aspect of morphology or physiology, within the Order to which it belongs (e.g. Anura, Passeriformes etc.)? | No aspect of biology known to be exceptional | Some populations of the species have a radiated pattern |
| 15 | Cultural/socio-economic importance | Does the taxon have a special human cultural value (e.g. as a national or regional symbol, in a historic context, featuring in traditional stories) or economic value (e.g. food, traditional medicine, tourism) within its natural range or in a wider global context? | No | |
| 16 | Scientific importance | Is the species vital to current or planned research other than species-specific ecology/biology/conservation within the Order to which it belongs (e.g. Anura, Passeriformes etc.) e.g. human medicine, climate change, environmental pollutants and conservation science? | No research dependent on this species | |
| 17 | Ex situ research | Does conserving this species (or closely related species) in situ depend upon research that can be most easily carried out ex situ? | No | |
| 18 | Ex situ conservation activities | Is any ex situ research or other ex situ conservation action currently in place for this species? (Information from the Conservation Actions section of the Red List assessment should be reviewed and considered when answering this question.) | No / unlikely | |
| 19 | Husbandry analog required | If an ex situ rescue program is recommended for this species, would an analog species be required to develop husbandry protocols first? | Yes / probably | Raorchestes tinniens would be a good husbandry analog for this species. |
| 20 | Husbandry analog | Do the biological and ecological attributes of this species make it suitable for developing husbandry regimes for more threatened related species? i.e. could this species be used in captivity to help to develop husbandry and breeding protocols which could be used for a similar, but more endangered species at a later stage? | No | |
| 21 | Captive breeding | Has this species been successfully bred and/or maintained in captivity? | Not held in captivity to date | |
| 22 | Conservation education/ecotourism potential | Is the species especially diurnal, active or colourful, or is there an interesting or unusual aspect of its ecology that make it particularly suitable to be an educational ambassador for conservation of the species in the range country, either in zoos or aquariums or within ecotourism activities? | No | |
| 23 | Mandate | Is there an existing conservation mandate recommending the ex situ conservation of this taxon? | No | |
| 24 | Range State approval | If an ex situ initiative was proposed for this species, would it be supported (and approved) by the range State (either within the range State or out-of-country ex situ)? | Yes / probably | |
| 25 | Founder specimens | Are sufficient animals of the taxon available or potentially available (from wild or captive sources) to initiate an ex situ program, if one was recommended? | Yes / probably | |
| 26 | Taxonomic status | Has a complete taxonomic analysis of the species in the wild been carried out, to fully understand the functional unit you wish to conserve (i.e. have species limits been determined)? | Yes |
Citation:
Nikhil Modak, Rajkumar K.P., S.R. Ganesh and S.R. Chandramouli 2020. Conservation Needs Assessment for Raorchestes signatus, India
(AArk/ASG India Assessment Workshop).
https://conservationneeds.org/assessment/5697
Accessed 23 Jan 2025
