Journal of Threatened Taxa | www.threatenedtaxa.org | 26 January 2016 | 8(1): 8379–8382

 

 

New locality record of the Travancore Bush Frog Raorchestes travancoricus Boulenger, 1891 (Amphibia: Anura: Rhacophoridae) from Periyar Tiger Reserve, Kerala, India

 

K.P. Rajkumar 1, T.S. Prasad 2, Sandeep Das 3, R. Sreehari 4, P.S. Easa 5 & K.A. Sreejith 6

 

1,2,3,5,6 Forest Ecology and Biodiversity Conservation Division, Kerala Forest Research Institute, Peechi, Kerala 680653, India

1,3 University of Calicut, Thenhipalam, Malappuram District, Kerala 673635, India

4 Ecologist, Periyar Tiger Conservation Foundation, Thekkady, Kerala 685536, India

1 rajkumarkp@kfri.res.in, 2 prasadambadyonline@gmail.com, 3 sandeep.koodu@gmail.com, 4 sree.forestry@gmail.com, 5 easaelephant@yahoo.com, 6 sreejith@kfri.res.in (corresponding author)

 

 

 

 

doi: http://dx.doi.org/10.11609/jott.2139.8.1.8379-8382 | ZooBank: urn:lsid:zoobank.org:pub:BD39E226-AFDB-4532-918E-5BF0DF11A400

 

Editor: Anonymity requested. Date of publication: 26 January 2016 (online & print)

 

Manuscript details: Ms # 2139 | Received 09 July 2015 | Final received 05 January 2016 | Finally accepted 07 January 2016

 

Citation: Rajkumar, K.P., T.S. Prasad, Sandeep Das, R. Sreehari, P.S. Easa & K.A. Sreejith (2016). New locality record of the Travancore Bush Frog Raorchestes travancoricus Boulenger, 1891 (Amphibia: Anura: Rhacophoridae) from Periyar Tiger Reserve, Kerala, India. Journal of Threatened Taxa 8(1): 8379–8382; http://dx.doi.org/10.11609/jott.2139.8.1.8379-8382

 

Copyright: © Rajkumar et al. 2016. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

 

Funding: Kerala Forest Department, WL10-10886/2013 dated on 11/4/2013.

 

Conflict of Interest: The authors declare no competing interests.

 

Acknowledgements: The authors are thankful to the Chief Wildlife Warden, Kerala for providing permission to conduct the study (WL10-10886/2013) and extending our gratitude to Kerala Forests and Wildlife Department for financial support. We express our sincere gratitude to Dr. Amit Mallick IFS, Mr. Sanjayan Kumar IFS, Mr. C. Babu, Mr. M. Ajeesh, Mr. S. Sandeep and officials of Periyar Tiger Reserve Conservation Foundation for their support. We gratefully acknowledge the Cornell Lab of Ornithology-Bioacoustics Research Program for supporting us with the Raven Pro v1.4 software. We acknowledge the support of the Director, KFRI and Ms. Lilly Margaret Eluvathingal for reviewing the manuscript and Mr. Sanil Mohan for assistance in fieldwork.

 

Abstract: Raorchestes travancoricus is a rare and endemic rhacophorid from southern Western Ghats. The frog was listed in the Extinct category of the IUCN Red List until June 2015, even after its rediscovery in 2004. In June 2015, the R. travancoricus was reassessed to Endangered category. All published reports of the species are restricted to disturbed habitats outside protected areas and the current study report the presence of the species from eight different localities from a protected area the Periyar Tiger Reserve.

Keywords: Amphibia, Bush Frog, Periyar, Raorchestes.

 

 

 

Raorchestes travancoricus was listed in the Extinct category of the IUCN Red List (Biju 2004) until June 2015 even after the rediscovery of the frog from Vandiperiyar in 2004. It was reassessed as Endangered B2ab(iii) based on the area of occupancy as restricted to 30km2 (IUCN SSC Amphibian Specialist Group 2015). The current status is based on the presence of the species in three locations, Vagamon, Vandiperiyar, and Periyar Tiger Reserve. We here report the presence of the species from eight different localities in Periyar Tiger Reserve (PTR), all through direct visual sighting. All the current reports of the species are restricted to disturbed habitats outside protected areas. Presence of this ‘rare’ species in several marshy grassland ecosystems, locally called ‘vayals’, in the Tiger Reserve indicates the need for a sound management strategy for the habitat, which holds the only known population of Raorchestes travancoricus within a protected area.

The Travancore Bush Frog Raorchestes travancoricus (Boulenger, 1891) is one of the least known rhacophorids of the Western Ghats. R. travancoricus was initially described as Ixalus travancoricus based on a single female specimen collected by H.S. Ferguson from ‘Bodanaikanur’ (Bodinayakkanur), presently in Tamil Nadu close to the Kerala border (Biju & Bossuyt 2009). Since there were no reports since the description R. travancoricus was listed Extinct in the IUCN Red List (Biju 2004). Later, Biju & Bossuyt (2009) reported the rediscovery of R. travancoricus based on the sighting of a male frog from Vandiperiyar, 70km southwest of the type locality in 2004, and two male frogs from Vagamon in 2006, both in non-protected areas. In this study, we report eight records of R. travancoricus from Periyar Tiger Reserve. We also present a preliminary analysis of the call of the species.

Raorchestes travancoricus was observed from Periyar Tiger Reserve on four occasions in the Uppupara region in Azhutha Forest Range in August and September 2014. A single male was first found calling 1m high on Ageratina adenophora (Sticky Snakeroot / Crofton weed) in a marshy grassland ecosystem (vayal) at 18.00hr in Uppupara Thannithotti Vayal on 26 September 2014 (Images 1 & 2). A total of 36 individuals were sighted and a single male specimen was collected and morphometric measurements were taken to the nearest 0.1mm with a Mitutoyo digital vernier calliper using a binocular microscope. The specimen is deposited in the wildlife museum of Kerala Forest Research Institute, Peechi. The identity was confirmed from the yellowish-pink colouration with distinct brown lines on the dorsum, dark brown streak on each side of the snout. Small snout vent length (SVL 26.49mm), snout oval in dorsal view, head wider (HW 8.0mm) than the head length (HL 7.71 mm), snout length (SL) 3.8mm. Skin of snout region, between eyes, upper eyelids, side of head and anterior and posterior parts of back shagreened. Loreal and tympanic region light brown with a prominent streak on each side of the snout from the extreme tip of the snout to the lower level of the supra-tympanic fold. The minimum distance between upper eyelids (IUE) 3.69mm and maximum width of upper eyelid is (UEW) 1.69mm. Eye length (EL) 3.45mm. Nuptial pad absent, body slender, canthus rostralis indistinct, loreal region acutely concave, tympanum indistinct, supratympanic fold indistinct. Fore limb (FLL 5.57) shorter than hand (HAL 5.1mm), fingers without lateral dermal fringe. Subarticular tubercles prominent, rounded and single. Supernumerary tubercles weekly developed. Hind limbs moderately long (Thigh length TL 12.2mm, Shank length SHL 11.9mm, Tarsus lengh Tal 6.7mm, Foot length Fol 9.41mm). Dorsal part of forelimb and hind limb shagreened, webbing reduced, subarticualr tubercles rather prominent, rounded and simple. Upper and lower parts of flank shagreened to sparsely granular. Chest, belly and posterior surface of thighs granular.

 

 

 

 

Call description

The calls were recorded using ZOOM H4nSP Handy Recorder from Uppupara in Periyar Tiger Reserve and the calls were analyzed by using the software Raven v1.4 software (Cornell Laboratory of Ornithology, Ithaca, NY, USA) (Bee et al. 2013a,b; Thomas et al. 2014). The waveform and frequency of the call described is given in Fig. 1 and Fig. 2, respectively (Audio 1).  Call duration was 2.2 second with two distinct notes and the first note was relatively shorter (0.6 second). The second note was long and 1.1 second in duration. The dominant frequency of both the notes was about 2.7kHz (Fig. 2) and compared to the second one the first note was relatively lower in amplitude (Fig. 1). Though the dominant frequency was within the range of its published sister taxa R. graminirupes (Bee et al. 2013b), the duration of both notes of R. travancoricus is relatively much longer than that of both notes of R. graminirupes.

 

 

 

 

The previous report of occurrence of the species is also close to the present area (Biju & Bossuyt 2009). Further investigation on the same day from 18.00hr to 01.00hr resulted in the sighting of 19 individuals from 20 10x10m quadrats laid randomly in the 1.21 acre vayal. Out of them 12 males (gender confirmed by presence of single subgular vocal sac) were found calling, sitting 1–2 m high from the ground on grass clumps present in the vayals. An amplected pair was found moving through grass, entered deep inside a grass clump (Chrysopogon nodulibarbis) and was then not followed to avoid disturbance. Random searching in the adjacent areas in different habitats resulted in 36 encounters, all of them on grasses or bushes in vayals and open grasslands. However, not a single encounter was observed in the surrounding evergreen forest patches, suggesting that this species is a vayal specialist.

 

 

 

R. travancoricus was also observed from seven other localities in Periyar Tiger Reserve, viz., Gavi, Upper Manalar, Eravangalar, Mangaladevi, Kumarikulam, Moolavaika and Chokkampatti during the herpetofaunal survey by the authors and the range of the species extends further south of Vandiperiyar, and increasing the altitudinal range up to 1800m. Even though the species was observed from the above seven locations in Periyar Tiger Reserve, detailed survey was carried out only at Uppupara. The details of locations of sightings of the species is summarised in Table 1 and the locations in PTR plotted in the Image 3. A detailed survey in similar habitats of Periyar Tiger Reserve is suggested to explore the possibility of more populations of the species to gauge its current distribution. Future research is required to understand the habitat preference and distribution of this species. By reporting marshy grasslands in PTR as new localities for R. travancoricus, the current study also highlights the importance of conservation and management of the vayal ecosystem in Periyar Tiger Reserve.

 

 

 

References

Bee, M.A., R. Suyesh & S.D. Biju (2013a). The vocal repertoire of Pseudophilautus kani, a shrub frog (Anura: Rhacophoridae) from the Western Ghats of India. Bioacoustics 22(1): 67-85.

Bee, M.A., R. Suyesh & S.D. Biju (2013b). Vocal behavior of the Ponmudi Bush Frog (Raorchestes graminirupes): repertoire and individual variation. Herpetologica 69(1): 22-35.

Biju, S.D. & F. Bossuyt (2009). Systematics and phylogeny of Philautus Gistel, 1848 (Anura, Rhacophoridae) in the Western Ghats of India, with descriptions of 12 new species. Zoological Journal of the Linnean Society 155(2): 374-444.

Bioacoustics Research Program (2014). Raven Pro: Interactive Sound Analysis Software (Version 1.4) [64bit]. Ithaca, NY: The Cornell Lab of Ornithology. Available from http://www.birds.cornell.edu/raven. Downloaded on 15 October 2015.

Boulenger, G.A. (1891). Description of a new species of frog obtained by Mr. H.S. Ferguson in Travancore, South India. Journal of the Bombay Natural History Society 6: 450.

IUCN SSC Amphibian Specialist Group (2015). Raorchestes travancoricus. The IUCN Red List of Threatened Species 2015: e.T58927A3075035. Downloaded on 17 October 2015; http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T58927A3075035.en

Thomas, A., R. Suyesh, S.D. Biju & M.A. Bee (2014). Vocal behavior of the elusive purple frog of India (Nasikabatrachus sahyadrensis), a fossorial species endemic to the Western Ghats. PloS ONE 9(2): e84809; http://dx.doi.org/10.1371/journal.pone.0084809