Bioacoustics of Microhyla sholigari

Diagnosis. Dutta & Ray (2000) provided a diagnosis on a subadult female individual (ZSI A9061). A comprehensive diagnosis is provided here based on an adult male individual of Microhyla sholigari and it can be distinguished from all other congeners in the Indian subcontinent by the following suite of characters: (i) A very small sized adult frog (male: 15.9–16.2 mm , N = 3 and female: 16.5–19.2 mm , N = 4); (ii) snout pointed in dorsal and ventral view with indistinct canthus rostralis, snout protrudes beyond mouth in ventral view; (iii) tongue oval with complete margin lacking a lingual papilla; (iv) tympanum indistinct; (v) head wider than long; (vi) skin smooth on dorsum and venter; (vii) throat buff colored with brown pigmentation; (viii) reduced webbing in feet, reaching proximal tubercle on the fourth toe on the inside; (ix) disc on fingers with circum-marginal groove, cover notched distally and disc on toes with circum-marginal groove, cover bifurcate distally. Differential diagnosis. Microhyla sholigari is compared with congeners from India , namely M. berdmorei , M. butleri , M. chakrapanii , M. heymonsi , M. laterite , M. ornata , M. pulchra and M. rubra . Microhyla sholigari differs from M. berdmorei in size (SVL, male: 15.9–16.2 mm , female: 16.5–19.2 mm vs. male: 25–28 mm , female: 27–45 mm ); webbing in feet (reaching proximal tubercle on fourth toe on the inside vs. full webbing); number of pulse per call (64–72 vs. 3–9) and dominant frequency (3375–3704 Hz vs. 1500–1800 Hz). Microhyla sholigari differs from M. butleri in size (SVL, male: 15.9–16.2 mm , female: 16.5–19.2 mm vs. male: 21–23 mm , female: 23–26 mm ); snout (pointed vs. rounded); webbing in feet (reaching proximal tubercle on fourth toe on the inside vs. nearly half); number of pulse per call (64–72 vs. 6–7) and dominant frequency (3375–3704 Hz vs. 1200–4500 Hz). Microhyla sholigari differs from M. chakrapanii in size (SVL, male: 15.9–16.2 mm , female: 16.5–19.2 mm vs. male: 22 mm ); snout (pointed vs. rounded) and discs on finger (present vs. absent). Microhyla sholigari differs from M. heymonsi in size (SVL, male, 15.9–16.2 mm vs. 21.5–24.4 mm ); no lateral band from snouth to groin vs. a continuous dark lateral band from the end of the snout to the groin and number of pulse per call (64–72 vs. 11–17). Microhyla sholigari differs M. laterite in vocal sac (cream with sparse brown pigmentation vs. purplish black); webbing in feet (reaching proximal tubercle on fourth toe on the inside vs. reaching distal tubercle on fourth toe on the inside); dorsal pattern (strongly constricted vs. less constricted) and number of pulse per call (64–72 vs. 90– 126). Microhyla sholigari forms a sister relationship with M. laterite and a detailed comparison is provided in Seshadri et al . (2016) . Microhyla sholigari differs from M. ornata in size (SVL, male, 15.9–16.2 mm vs. 18–21 mm ); discs on fingers and toes (present vs. absent); vocal sac (cream with sparse brown pigmentation vs. greyish black) and number of pulse per call (64–72 vs. 8–14). Microhyla sholigari differs from M. pulchra in size (SVL, male: 15.9–16.2 mm , female: 16.5–19.2 mm vs. male: 35 mm ); discs on fingers and toes (present vs. absent) and webbing in feet (reaching proximal tubercle on fourth toe on the inside vs. nearly half). Microhyla sholigari differs from M. rubra in size (SVL, male, 15.9–16.2 vs. 25.8–29.6 mm ); discs on fingers and toes (present vs. absent); vocal sac (cream with sparse brown pigmentation vs. black) and number of pulse per call (64–72 vs. 15–21).

Geographic range extension and IUCN status. We encountered this species in localities in Western Ghats including one locality in the outskirts of the city of Bengaluru (Shivanalli), which is outside the Western Ghats boundary ( Fig. 1 , Table 1 ). From the type locality, the new range of M. sholigari extends to about 284 km to the north-west. The localities vary from forests inside protected areas to open fallow land outside of the Western Ghats . The geographic extent of occurrence as determined from the minimum convex hull was 28,304.6 km 2. This species is locally abundant (> 50 calling male individuals/ 100 m 2 were observed at Bisle, BRTTR and Shivanalli). There is however, limited information on population size, fluctuation and trends, the number of individuals and generation length. M. sholigari being widespread, does not occur in any one geographically and distinct ecological location. Additionally , there appear to be no sub-population effects as indicated by the low genetic divergence between the two locations sampled in this study ( Table 3 ). In light of the extended geographic range, this species no longer meets the requirements to be classified as Endangered under the criteria of B1ab(iii) or any other category, and thus, we suggest down-listing M. sholigari to Least Concern (LC) instead.