Bioacoustics of Mantidactylus augustini

Identity and justification .—This lineage is a member of the M. biporus clade from the lowlands of the North East of Madagascar and has previously been considered as confirmed candidate species M. sp. 22 by Vieites et al. (2009) and M. sp.Ca22by Perl et al. (2014) .It was depicted as ‘ Mantidactylus sp. aff. biporus “Andranofotsy”’ by Glaw and Vences (2007) . This lineage is sister to the true M. biporus according to our phylogenomic analysis, but is characterized by a high uncorrected pairwise-distance in the 16S rRNA marker (4.9–5.8%). It also is concordantly differentiated in the nuclear Rag-1 gene, not sharing its haplotype with M. biporus ( Fig. 4 ). Moreover, the two lineages differ distinctly in male advertisement call. Based on the concordance of high mitochondrial divergence with nuclear and bioacoustic differentiation, we are convinced it represents a distinct species. A deep conspecific lineage of M. augustini sp. nov. co-occurs with the main lineage in Masoala. As we have only limited data on this lineage, we tentatively include it in our circumscription of this species, but note that it may later transpire to represent another distinct species.

Natural history .—At the type locality, calling males were observed at night from the shore of a very shallow running water of a spring in rainforest. Voucher Field number Sex Locality SVL HW HL ED HTD END NSD NND FORL HAL HIL FOTL FOL TIBL FGL FGW Mantidactylus biporus BMNH 1947.2.26.47 [LT*] NA F Madagascar 35.8 13.7 13.9 4.7 2.8 2.8 1.7 3.7 18.1 8.5 51.2 22.3 15.3 NM NA NA BMNH 1947.2.26.48 # [PLT] NA F? Madagascar 28.0 12.1 10.0 4.6 2.3 2.8 1.9 3.5 9.4 8.6 NM NM 12.2 12.8 1.5 1.2 BMNH 1947.2.26.50 # [PLT] NA F? Madagascar 29.4 11.3 9.7 4.2 2.5 2.4 1.8 3.3 10.0 7.2 NM NM 12.6 12.0 1.4 1.2 BMNH 1947.2.26.49 [PLT] NA M Madagascar 29.9 10.7 11.9 4.1 3.1 2.7 2.2 2.7 15.9 7.8 41.7 19.5 13.6 NM 3.9 2.5 MRSN A6180 FAZC 13480 M Betampona 31.6 12.6 12.5 4.8 3.3 2.7 2.6 3.6 17.4 8.7 43.3 20.1 14.0 12.8 3.0 2.2 MRSN A6266 FAZC 13675 M Betampona 29.9 12.0 12.1 4.9 3.7 2.9 2.1 3.7 16.6 8.0 41.5 19.4 14.0 11.5 3.3 2.1 MRSN A6374 FAZC 13835 M Betampona 31.0 12.6 12.7 4.5 3.4 2.7 2.2 3.3 17.6 8.4 42.0 19.6 14.1 12.5 3.4 2.7 ZSM 1982/2006 ZCMV 2425 M An’Ala 28.0 11.0 11.0 3.8 3.0 2.7 1.7 2.7 15.1 7.0 38.2 17.3 11.8 11.2 2.3 1.8 ZSM 396/2006 ZCMV 1483 F An’Ala 30.5 11.5 11.4 4.3 3.0 2.8 1.7 2.9 16.0 8.0 42.9 18.7 13.2 12.1 1.4 1.2 ZSM 184/2021 ACZCV 201 F? Betampona: Vohitsivalana 19.3 8.0 8.6 2.8 1.8 2.4 1.8 2.7 11.0 5.7 29.2 13.2 8.7 8.6 NA NA Mantidactylus augustini sp. nov. (Ca22) ZSM 122/2002 [HT] FGMV 2001.1388 (2002. A4) M Andranofotsy 23.9 10.1 10.3 3.9 3.2 2.5 1.6 2.8 15.9 6.9 36.7 16.9 11.7 10.5 3.3 2.0 MRSN A3600 [PT] FN 7678 (ACZC 4904) F Masoala forest 25.0 9.6 10.3 3.7 3.4 1.6 1.6 3.0 14.8 7.5 38.3 17.0 11.8 10.6 NA NA ZFMK 70481 # NA F Masoala 24.2 9.5 9.0 3.8 2.6 2.0 1.8 3.0 9.7 6.8 NM NM 10.4 11.4 1.4 1.3 ...Continued on the next page Voucher Field number Sex Locality SVL HW HL ED HTD END NSD NND FORL HAL HIL FOTL FOL TIBL FGL FGW MRSN A2905 [PT] FN 7238 (ACZC 4897) F? Masoala forest 24.4 10.3 10.8 4.0 2.9 2.7 1.7 3.0 NM 7.4 NM 17.4 12.6 11.1 NA NA MRSN A3540 [PT] ACZC 4898 F? Masoala forest 22.6 9.3 10.0 3.7 2.4 2.4 1.6 2.9 14.8 6.9 37.8 17.4 11.8 11.1 NA NA ZSM 740/2009 [PT] ZCMV 11170 F Melivinany, Manompana 20.9 8.2 8.6 3.1 2.7 1.9 1.7 2.9 13.9 6.6 33.0 15.3 10.9 9.8 1.7 1.3 MRSN A6740 [PT] FAZC 14292 (ACZC 4906) FJ? Farankaraina 16.4 NM NM NM NM NM NM NM NM NM NM NM NM NM NA NA MRSN A3737 [PT] FAZC 10009 (ACZC 4905) J Masoala forest 16.4 NM NM NM NM NM NM NM NM NM NM NM NM NM NA NA Mantidactylus bletzae sp. nov. ZSM 829/2014 [HT] ZCMV 14771 F Ivohibe 27.3 10.6 10.5 3.4 2.4 1.8 1.8 3.0 16.1 7.9 41.0 18.6 12.2 12.4 NA NA ZSM 827/2014 [PT] ZCMV 14763 F Ivohibe 25.8 9.8 9.9 3.4 2.6 2.0 1.6 2.9 15.5 7.4 39.3 18.1 12.2 11.8 NA NA ZSM 828/2014 [PT] ZCMV 14768 F Ivohibe 26.2 9.8 10.1 3.5 2.3 2.1 1.7 2.6 15.6 8.3 40.5 18.6 12.3 12.0 NA NA Mantidactylus brevirostris sp. nov. MRSN A6257 [HT] FAZC 13581 M Betampona: Sahamben- drana 23.2 8.8 9.3 3.5 2.7 2.4 1.6 3.4 14.7 6.5 34.9 15.6 10.7 10.4 2.7 1.6 ZSM 185/2021 [PT] ACZCV 265 F Betampona: Sahabefoza 28.4 11.3 11.4 3.8 2.6 2.4 1.6 2.8 16.3 7.3 40.6 17.9 12.0 12.0 NA NA Mantidactylus eulenbergeri sp. nov. (Ca23) ZSM 85/2002 [HT] FGMV 2001.1092 M Andasibe 21.6 9.2 8.7 3.3 3.0 1.8 1.4 2.3 12.5 5.7 29.7 13.2 9.0 7.9 3.4 2.3 ZFMK 62214 # NA M Andasibe 23.3 9.1 8.1 3.7 2.7 2.1 1.8 2.5 9.2 6.6 NM NM 10.1 10.1 2.2 2.2 ...Continued on the next page ) Voucher Field number Sex Locality SVL HW HL ED HTD END NSD NND FORL HAL HIL FOTL FOL TIBL FGL FGW MRSN A7047 [PT] FAZC 15517 M Maromizaha 21.9 9.5 9.5 3.5 3.1 2.1 1.7 2.9 13.9 6.4 32.4 14.8 10.0 9.6 2.5 1.5 MRSN A7048 [PT] FAZC 15549 M Maromizaha 20.9 8.1 8.6 3.0 2.5 1.8 1.8 2.7 12.0 6.3 31.2 13.9 9.7 9.4 2.0 1.4 ZSM 199/2021 [PT] FAZC 15516 M Maromizaha 20.5 8.8 9.2 3.3 2.5 1.8 1.7 3.0 12.6 6.5 30.3 13.7 9.5 9.4 2.7 1.6 MRSN A6700 [PT] RJS 1820 (ACZC 4200) F Anivorano Est forest 26.4 11.1 12.3 4.4 2.9 2.5 2.0 3.4 16.2 7.6 39.3 17.8 12.0 12.0 NA NA ZSM 84/2002 [PT] FGMV 2001.1090 F Andasibe 28.0 10.5 10.7 3.5 2.6 2.1 1.9 2.9 15.6 7.4 39.0 17.1 11.9 11.4 2.3 1.0 ZSM 198/2021 [PT] FAZC 15509 F Maromizaha 26.7 10.4 11.0 3.4 2.4 2.1 2.0 2.5 16.0 7.9 35.6 16.0 10.0 10.4 NA NA MRSN A7049 [PT] FAZC 15540 F Maromizaha 25.0 10.1 11.0 3.6 2.5 1.9 1.9 3.0 14.1 7.2 37.4 16.8 11.6 11.0 NA NA ZSM 919/2003 [PT] FGMV 2002.949 F Vohidrazana 20.0 8.5 8.5 3.2 2.3 1.9 1.1 2.3 12.6 5.8 29.4 13.9 9.3 9.0 1.4 1.2 Mantidactylus glosi sp. nov. ZSM 434/2006 [HT] ZCMV 3366 M Ranomafana 21.0 8.7 8.6 3.2 2.8 2.1 1.4 2.3 11.9 5.6 28.9 13.5 9.3 9.1 2.5 1.5 ZSM 433/2006 [PT] ZCMV 3364 F Ranomafana 25.1 9.7 10.0 3.4 3.1 2.3 1.4 2.5 13.8 6.5 34.1 16.0 11.3 10.1 1.2 1.0 Mantidactylus stel- liger sp. nov. ZSM 2381/2007 [HT] ZCMV 5932 M Ambohitsara 22.6 9.7 10.0 3.9 2.6 2.1 1.5 2.6 13.8 6.4 33.1 15.0 9.8 9.9 2.8 2.2 ZSM 2380/2007 [PT] ZCMV 5922 M Ambohitsara 21.6 8.8 9.4 3.4 2.5 2.0 1.6 2.8 13.8 6.4 33.3 14.9 10.2 10.1 2.6 1.9 ZSM 2379/2007 [PT] ZCMV 5870 F Ambohitsara 31.1 13.0 13.2 4.6 3.4 2.8 2.6 3.0 19.1 9.3 46.2 20.8 14.5 13.6 1.1 0.8 Calls .—The advertisement call of M. augustini , recorded on 16 December 2001 near Andranofotsy, 25.4°C air temperature ( Vences et al. 2006 : CD2, track 72), consisted of a short, pulsed note, emitted in regular series at fast succession ( Fig. 66 ). Pulse repetition rate was distinctly lower at the beginning of calls and increased after approximately one half of the call’s duration. Amplitude modulation was present, with relative amplitude increasing from the beginning of the call, reaching its maximum at the last quarter of the call’s duration. Numerical parameters of seven analysed calls were as follows: call duration (= note duration) 154–236 ms (178.8 ± 26.6 ms); 9–15 pulses per note (10.4 ± 2.1); pulse duration 7–12 ms (9.1 ± 1.6); pulse repetition rate within notes 44.4–71.4 pulses/s (59.0 ± 10.3); dominant frequency 1263–1356 Hz (1304 ± 39 Hz); prevalent bandwidth 700–3150 Hz; call repetition rate (= note repetition rate) within regular series ca 200– 230 calls/min.

Diagnosis.— M. augustini sp. nov. is a member of the M. biporus clade, sister to M. biporus according to our phylogenomic analysis. See Table 4 for a list of diagnostic morphological characters. The combination of a small body size (male SVL 24 mm , female SVL 21–25 mm ), rather smooth dorsal skin with weakly expressed dorsolateral ridges in some individuals, large tympanum size in males (13% of SVL), presence of white spots on flanks, absence of a white marking on the snout tip, and a short, pulsed advertisement call emitted in regular series, distinguishes M. augustini sp. nov. from species of the M. betsileanus , M. curtus , M. fergusoni , M. tricinctus , and M. ulcerosus clades. Mantidactylus inaudax ( M. inaudax clade) is morphologically similar but appears to have shorter hindlimbs, less pulses per note, and higher pulse repetition rate in advertisement calls. M. augustini sp. nov. is distinguished from its sister species, M. biporus , by smaller body size, larger tympanum, longer hindlimbs, more pulses per note and a lower pulse rate in advertisement calls ( Table 4 ), as well as a higher dominant frequency (1263–1356 Hz vs 832–997 Hz), and a lower call repetition rate (200–230 vs 300–360 calls/ min). For a distinction from the other (all new) species in the M. biporus , M. stelliger and M. inaudax clades, see the diagnoses in the respective species accounts below. A full list of molecular diagnostic sites in the 16S gene of M. augustini sp. nov. in pairwise comparisons to all other Brygoomantis species is provided as Supplementary appendix.