Bioacoustic analysis of advertisement call in Hyla nana and Hyla sanborni (Anura, Hylidae) in Botucatu, São Paulo, Brazil

Abstract

Vocal communication traits of Hyla nana and Hyla sanborni, of the nana species group, were studied from August 1997 until June 1999 in two large permanent ponds located in an open field in Botucatu, São Paulo State. One hundred thirty-one individuals, 71 of H. nana and 58 of H. sanborni, were recorded in the beginning of their vocalization activity and during chorus vocalization. The rhythms of sound emission on the two occasions were different. An advertisement call consists in a consecutive series of simple notes in rapid succession. Both species have two types of notes in their advertisement calls, here named types A and B. Type A notes are introductory and have a longer and higher pulse number and are emitted more frequently in the beginning of vocalization activity. Introductory notes are the first to be emitted in chorus activity. Type B notes are secondary, of shorter duration and lower pulse number, and are emitted during chorus vocalization. The notes of both types differ significantly in their temporal structure. Both species present acoustic segregation in both spectral and temporal structure.

Bioacústica e sítio de vocalização em taxocenoses de anuros de área aberta no noroeste paulista

“…O canto de anúncio é um sinal específico que as fêmeas utilizam para distinguir os machos co-específicos e, assim, formar casais reprodutores (Ryan & Rand 1993), e pode ser constituído por notas simples, por uma série de notas idênticas ou por uma combinação de um ou mais grupos de notas com diferentes propriedades acústicas (Duellman 1970 O canto de anúncio da maior parte das espécies não diferiu dos cantos registrados para populações das mesmas espécies em outras localidades do Brasil (Bastos et al 2003, Martins & Jim 2003, Toledo & Haddad 2005. Apenas a freqüência dominante do canto de anúncio de Dendropsophus minutus foi semelhante à encontrada por Duellman (1978), em torno de 3 kHz, mas diferiu da faixa de 3,5 a 5,0 kHz, descrita por Cardoso (1981).…”

“…A vocalização tem um papel importante nas agregações reprodutivas, mantendo o espaçamento entre os machos e atraindo fêmeas (e.g., Gerhardt 1994, Ryan 2001. O canto de anúncio é a vocalização mais freqüentemente emitida pelos machos (Wells 1977), pois contém informações espectrais e/ou temporais importantes para o reconhecimento específico (Gerhardt 1983, Ryan 1985, Cocroft & Ryan 1995, e apresenta adaptações que evitam ou minimizam a interferência acústica na comunicação (Grafe 1996, Martins & Jim 2003, Martins et al 2006, permitindo a coexistência de várias espécies no mesmo ambiente (Duellman & Pyles 1983, Cardoso & Viellard 1990, Márquez et al 1993, Bastos & Haddad 1995, Viellard & Cardoso 1996, Martins & Jim 2003e Martins et al 2006). Do ponto de vista da comunidade, a análise da vocalização indica que as espécies simpátricas vocalizam com diferenças significantes e com pequena sobreposição nos parâmetros acústicos (Duellman 1967, Hödl 1977, Cardoso & Viellard 1990, embora este padrão nem sempre seja encontrado (Chek et al 2003).…”

Habitat heterogeneity and use of physical and acoustic space in anuran communities in Southeastern Brazil

“…The following call features were determined: note duration (including duration of different notes in calls with more than one type of note); pulse number per note, lower and higher band frequency, lower and higher dominant frequency, and harmonic number. The terminology of call features follows Duellman and Pyles (1983), Duellman and Trueb (1994), and Martins and Jim (2003). Bioacoustics analysis was performed using the software CoolEdit Pro, 2.0 version, with 22000 Hz sample frequency, option of 256 bands (FFT -Fast Fourier Transform).…”

Advertisement and release calls of Phyllomedusa ayeaye (Anura: Hylidae) with comments on the social context of emission

“…), to record the release calls of each male either in the field on the same night or in the laboratory the day after male collection. We adopted the following terminology (adapted from MARTINS & JIM 2003, TOLEDO et al 2014): 1) call: a sequence of sounds produced and emitted in a temporal pattern; 2) note: temporally discrete vocalization units composing the call; and (3) pulse: subdivision of the note in smaller temporal units. We measured the following bioacoustic variables: number of short notes emitted in sequence, number of pulses/note, note duration (s), interval between notes (s), and minimum, maximum, and dominant frequencies (Hz).…”