Published in Herpetological Review, 37(1): 75-76
References
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Fig . 1. Pedostibes tuberculosus (male, snout-vent length = 38 mm) at Jakkanagadde, Shimoga, Karnataka. Scale bar: 10 mm.

Advertisement call patterns of anurans provide insights to speciation, territoriality, evolution and phylogeny as these patterens reveal the species identification and motivation to mate ( Bridges and Dorcas 2000, Copeia. 2000:587-592; Emerson 2001, In Ryan (ed.), Anuran Communication. pp. 36-43. Smithsonian Institution Press. Washington, D.C.). Anuran acoustics have been studied for 20 species of 113 from Western Ghats (Gururaja 2004, Sahyadri Mandooka: Amphibians of Western Ghats; Kadadevaru and Kanamadi 2001, Curr.Sci. 80:1486-1487; Kuramoto and Joshy 2001, Curr.Herpetol. 20:85-95). Herein we report on advertisement call , explosive breeding behaviour and distribution of Pedostibes tuberculosus, endemic to Western Ghats.

Pedostibes tuberculosus is a medium-sized tree toad (mean SVL ± SE: 37.18 ± 0.44 mm; Range: 36-38 mm; all male, N = 4, Fig. 1). Individuals have distinct sub-gular vocal sac. Calls of four individuals (ca. 1.3 m above ground) were recorded at 15-minute intervals using Olympus digital voice recorder W-10 as Differential Pulse Code Modulation at 15.5 kHz. Call were recorded less than 30 cm from the specimen amidst evergreen-semi-evergreen forest (RH 97%, 23.6°C) adjacent to a small perennial stream (marked in Fig. 2).

Fig . 2. Reported sightings of P. tuberculosus in Western Ghats

Calls were single and chorus, and antiphonal, heard for a month with the onset of southwest monsoon (June 2004). Chorus calls were synchronous, starts with an individual's initiation. Single calls of P. tuberculosus were a nalysed as per Littlejohn (2001.In Michael J. Ryan (ed.), Anuran Communication. pp. 102-120. Smithsonian Institution Press. Washington, D.C.)Each call lasted for 3-7 seconds had 14-37 pulse groups (PG) of 3-11 pulses with the domination of 4-8 PG, of which PG 1-2 (N = 16) had larger period (145.63 ± 21.72 ms) and interval (117.69 ± 22.09 ms) in the entire call series. Pulse frequency was 12.87-44.67 ( 34.82 ± 3.83). PG period was 61-134 ms. Amplitudes of first and last pulses of first and last pulse groups were low compared to others. Dominant frequency was 3782.13 ± 30.58 Hz. Pulse groups sounded like Shchirrrrrr shirrrr shirrr shirrr shirrr …..

Call structure of P. tuberculosus varies considerably from other bufonids in Western Ghats (Kanamadi et al. 1995. J. Adv.Zool . 16:5-11. ). Mean pulse rate of B. melanostictus was twice that of P. tuberculosus. However similarity was noticed between pulse rate of B. fergusonii and P. tuberculosus . The dominant frequency in B. melanostictus was 1450 Hz, in B. fergusonii it was 3175 Hz, and in P. tuberculosus 3782 Hz.. Synchronous calls in case of B. americanus , B. bombina , B. variagata , B. melanostictus and B. fergusonii of Bufonidae are attributed to explosive breeding behaviour (Duellman and Trueb 1986. The Biology of Amphibians. McGraw-Hill Book Inc., New York. U 670 pp; Kanamadi et al. 1995, op. cit. ). The same can be implied to P. tuberculosus of Bufonidae, which has similar call pattern.

Even though its presence was predicted ( Biju 200. Indian Soc. Con. Bio. 1:1-24; Das and Whitaker 1998. Herpetol. Rev. 29:173), there are no earlier reports from Karnataka spanning over 400 km of Western Ghats (earlier reports are marked in Figure 2). The new location is approximately 333 km north of Silent Valley (nearest southern range) and 222 km south of Cotegao Wildlife Sanctuary (nearest northern range).

Acknowledgements
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We thank the ISRO-IISc-Space Technology Cell; the Ministry of Environment and Forests, GOI; Indian Institute of Science for financial and infrastructure support. We thank Karnataka State Forest Department for granting necessary permissions and support during field work (PS PCCF.WL.CR-38/2004-05). We thank Sameer Ali, Vishnu and Lakshminarayan for their assistance during field investigations and Sudhira, Joby Joseph and Sreekantha for valuable suggestions on acoustics.

Literature Cited
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  1. Biju, S.D. 2001. A synopsis of frog fauna of Western Ghats of India. Indian Soc. Con. Bio. 1:1-24.
  2. Bridges, A. S., and M. E. Dorcas . 2000. Temporal variation in anuran calling behaviour: implications for surveys and monitoring programs. Copeia. 2000:587-592.
  3. Das, I., and R. Whitaker. 1998. Geographical distribution Pedostibes tuberculosus (Malabar tree toad). Herp. Rev. 29:173.
  4. Duellman, W. E., and L. Trueb. 1986. The Biology of Amphibians. McGraw-Hill Book Inc., New York. United States of America. 670 pp.
  5. Emerson, S.B. 2001. Male Advertisement Calls: Behavioral Variation and Physiological Processes . In Michael J. Ryan (ed.), Anuran Communication. pp. 36-43. Smithsonian Institution Press. Washington. United States of America.
  6. Gururaja, K.V. 2004. Sahyadri Mandooka: Amphibians of Western Ghats. http://wgbis.ces.iisc.ac.in/biodiversity/newsletter/issue6/index.htm
  7. Kadadevaru, G.G., and R.D. Kanamadi . 2001, Vocal interactions, territoriality and fighting behaviour of the rhacophorid frog, Philautus variabilis (Günther, 1858). Curr.Sci. 80:1486-1487.
  8. Kanamadi, R.D., C.R. Hiremath and H. Schneider. 1995. Vocalization of tropical Indian Toads, Bufo melanostictus and Bufo fergusonii . J. Adv.Zool . 16:5-11.
  9. Kuramoto, M., and S.H. Joshy. 2001. Advertisement call structures of Frogs from Southwestern India, with some ecological and taxonomic notes. Curr.Herp. 20:85-95.
  10. Littlejohn, M. J. 2001. Pattern of differentiation in temporal properties of Acoustic signals of anurans. In Michael J. Ryan (ed.), Anuran Communication. pp. 102-120. Smithsonian Institution Press. Washington. United States of America.
                   
    GURURAJA, K.V. *
    gururaj@ces.iisc.ac.in
    		 
    RAMACHANDRA, T.V. cestvr@ces.iisc.ac.in
    Energy & Wetlands Research Group (EWRG),
    Centre for Ecological Sciences (CES),
    Indian Institute of Science (IISc),
    Bangalore 560 012,
    India.

    * For correspondence