Hyperextended call note repertoire of the endemic Madagascar treefrog Boophis madagascariensis (Rhacophoridae)

Abstract

Vocalizations of Boophis madagascariensis (Rhacophoridae) males were recorded in a mid-elevation rain forest in eastern Madagascar. Call notes made by males of this species were classi®ed into 28 types. This represents the largest known call repertoire of any amphibian. The calls range widely in spectral characteristics from a narrowband, nearly pure-tone to broadband`rip' notes, to even broader band, pulsatile`iambic' notes consisting of up to 23 pulses. Even considering all`iambic' notes as variants of one type, there remain eight distinct call notes produced by this species. Morphological analysis of the vocal musculature of B. madagascariensis revealed no obvious adaptations for unusual glottal¯exibility or function. Playback studies using a subset of the call notes as stimuli were carried out in the animals' natural habitat to determine the functional signi®cance of several of the call notes. At the lowest playback levels, there was a signi®cant tendency for males to produce rip notes in immediate response to either rip or iambic note stimuli. At the higher playback levels, we identi®ed one sequence of iambic notes that consistently evoked a signi®cant iambic note response from males. A permutation test on call note transitions during spontaneous calling revealed that call note pairs occurred inconsistently and unpredictably. The evolutionary signi®cance of an extended vocal repertoire, matched counter-calling and a random call note production scheme is discussed.

Integrative inventory of Bolivia’s lowland anurans reveals hidden diversity

“…Anuran call variation and call repertoire have only rarely been described for single species (e.g. Narins et al 2000;Toledo & Haddad 2005), and the role and function of mate choice, mate competition and their consequences for speciation are not well understood. However, recent studies on within-species call variation suggest that acoustic traits seem to be subject to more rapid evolution than are other traits (for a review see Gerhardt & Huber 2002).…”

Acoustic sequences in non‐human animals: a tutorial review and prospectus

“…Kroodsma, 1985;Podos et al, 1992;reviewed in Catchpole & Slater, 2003), and acoustic sequences in other taxa (e.g. Narins et al, 2000;Larson, 2004). Humans are usually considered to be good at visual pattern recognition -and better than most computer algorithms (Ripley, 2007;Duda, Hart & Stork, 2012), which makes visual classification an attractive approach to identifying acoustic units.…”

“…Model validation techniques include the sequential and X 2 tests (Anderson & Goodman, 1957). For instance, Narins et al (2000) used a permutation test (Adams & Anthony, 1996) to evaluate the hypothesis that a frog with an exceptionally large vocal repertoire, Bufo madagascariensis, emitted any = P e (B-X ) = 0.5, and when in state Y , acoustic unit A is much more likely P e (A-Y ) = 0.9 than B P e (B-Y ) = 0.1. Transitioning from state X to state Y occurs with probability P t (X → Y ) = 0.6, whereas from state Y to state X with probability P t (Y → X ) = 0.3.…”

Call diversity of Leptodactylus natalensis Lutz, 1930 (Anura; Leptodactylidae)

“…Other studies have also shown complex calls of anurans (e.g. Narins et al, 2000;Feng et al, 2002;Brandão & Heyer, 2005;Toledo & Haddad, 2005). The intraspecific and/or individual variations are mainly in dominant frequency and duration of each note, number and sequence order of pulses or notes, but a high call diversity as observed in L. natalensis is not common.…”