Bioacoustics of Mantidactylus fergusoni

Identity and justification .—This lineage has been previously considered as confirmed candidate species M. sp. 26 by Vieites et al. (2009) and M. sp. Ca26 by Perl et al. (2014) . It was depicted as ‘ Mantidactylus sp. aff. betsileanus “Andranofotsy”’ by Glaw and Vences (2007) . Our phylogenomic analysis confirms that this lineage is in a major clade (here named the M. fergusoni clade) containing only scientifically unnamed lineages, and its status as distinct species is therefore out of question. However, deciding how many species exist in this clade is complicated. Mantidactylus sp. Ca26 forms a clade with several other divergent mitochondrial lineages of uncertain status; here we consider the lineage previously named M. sp. 21 ( Vieites et al. 2009 ) or M. sp. Ca21 ( Perl et al. 2014 ) from Nosy Mangabe, Makira, Masoala, and Cap Est/Ambato as conspecific with M. fergusoni (note that M. sp. 21 was wrongly placed in the tree of Vieites et al. [2009] , probably due to a sequence confusion in the alignment used for phylogenetic analysis). As a further deep conspecific lineage we consider samples from Marojejy and additional sites in the North East. Samples from Nosy Boraha ( M. sp. Ca27) according to our phylogenomic analysis ( Fig. 5 ) form a clade with the lineage M. sp. Ca25 (see Vieites et al. 2009 ) from different sites on the mainland adjacent to Nosy Boraha, and together are sister to M. fergusoni sp. nov. ; the Nosy Boraha population is described below as M. jahnarum sp. nov. based on its bioacoustic differentiation.

Diagnosis .—A member of the M. fergusoni clade as revealed by the phylogenomic analysis, and sister to M. jahnarum sp. nov. described below. See Table 4 for a list of diagnostic morphological characters. The combination of a small to moderate body size in males (SVL up to 25– 30 mm ) and distinctly larger body size in females ( 36– 42 mm ), tubercular dorsal skin, large tympanum size in males (10–14% of SVL), absence of white spots on flanks and of white marking on snout tip, and advertisement call consisting of a single-pulse note distinguishes M. fergusoni sp. nov. from most species of the other clades. Two species from the M. ulcerosus clade ( M. ulcerosus and M. bellyi ) can be morphologically similar, but they occur in the Sambirano and North West regions, and have strongly differing advertisement calls ( Table 4 ). One species of the M. betsileanus clade ( M. katae ) has an advertisement call of similar general structure, but has a faster and more regular call repetition rate, less tubercular dorsum, larger femoral glands, and a distinct white marking on snout tip ( Table 4 ). M. fergusoni sp. nov. may also show superficial similarities to other species of the M. betsileanus clade but does not appear to occur sympatrically with any of them; in general it has a more tubercular dorsum and differs from all of these by advertisement call structure ( Table 4 ). The M. fergusoni clade contains only species newly named herein; for a distinction from these other species, see below. A full list of molecular diagnostic sites in the 16S gene of M. fergusoni sp. nov. in pairwise comparisons to all other Brygoomantis species is provided as Supplementary appendix.

Calls .—The advertisement call of M. fergusoni , recorded on 16 December 2001 near Andranofotsy, 25.4°C air temperature ( Vences et al. 2006 , CD 2, track 69), consists of a simple, short, single pulse ‘click’ note, emitted in series ( Fig. 50 ). Inter-call intervals were irregular with some calls (= notes) occurring in pairs with lower inter-call interval inbetween. Call energy was distributed in a wide frequency band. Numerical parameters of 13 analysed calls were as follows: call duration (= note duration) 9–12 ms (10.5 ± 0.8 ms); 1 pulse per note (1.0 ± 0.0); pulse duration = note duration = call duration; dominant frequency 1626–1690 Hz (1669 ± 26 Hz); prevalent bandwidth 700–5700 Hz; call repetition rate (= note repetition rate) within series ca 210–290 calls/min. Calls recorded on 31 March 2010 at Ambodivohangy, Makira area (from specimen ZSM 361/2010 = FGZC 4219), 24°C estimated air temperature, agree with those described above from Andranofotsy, apart from somewhat lower call repetition rate within series. Calls consisted of a simple short ‘click’ note emitted isolated or more often in series at irregular intervals. Numerical parameters of 28 analysed calls were as follows: call duration (= note duration) 7–13 ms (8.9 ± 1.4 ms); 1 pulse per note (1.0 ± 0.0); pulse duration = note duration = call duration; dominant frequency 1571–1722 Hz (1638 ± 54 Hz); prevalent bandwidth 700–5500 Hz; call repetition rate (= note repetition rate) within series ca 100–170 calls/min. Tadpoles.— The tadpole of this species has not been described.