Bioacoustics of Microhyla nilphamariensis

( Fig 4K ) Specimens examined: five males (WIIAD 234, WIIAD 235, WIIAD 262–264) Morphological features : Adult males SVL 18.3–21 mm (n=5); head triangular, wider than long; snout nearly rounded in lateral view; pupil round; tympanum not visible, supratympanic fold present; dorsal skin smooth with small tubercles all over the upper and lateral side of body; fingers without webbing and flattened, relative length of fingers I <II <IV <III; toes long and thin, tips of toes rounded, rudimentary webbing in toes, relative length of toes 1<2<5<3<4, small round inner metatarsal tubercle. This species is described from Bangladesh by Howlader et al. (2015) but Garg et al. (2018b) reported its widespread distribution in India and perhaps earlier records of M. ornata from central India should be referred to M. nilphamariensis ( Garg et al. 2018b ) . Calling males had single subgular vocal sac. Coloration in life : Golden or pink dorsal with dark arrowhead markings on the back starting from eyes and widening towards hind limbs, tiny orange dots on dorsum; hind limbs cross-barred with dark brown; flank dark brown; throat black (calling males); ventral side of body white. Bioacoustics: We analysed 50 advertisement calls from five males. The calls were recorded between 20:00– 23:40 hours (July–September) and calling site temperature was between 25.7 °C–30.9 °C. Calling males produced distinct pulsatile calls. The calls were delivered mostly at uniform intervals. Calls had mean duration of 415.22 ± 130.31 ms (195–625 ms). Mean pulse rate was 44.04 ± 3.4 pulses/second (38.17–50.76 pulses/second) with 18.36 ± 5.82 pulses delivered per call (8–26 pulses). The mean dominant frequency was 3067.18 ±104.52 Hz (2928.50– 3273 Hz).