Studies on Neotropical Fauna and Environment ISSN: 0165-0521 (Print) 1744-5140 (Online) Journal homepage: https://www.tandfonline.com/loi/nnfe20 Variation among vocalizations of Taraba major (Aves: Thamnophilidae) subspecies Guilherme Sementili-Cardoso, Fernanda Gonçalves Rodrigues, Rafael Martos Martins, Raphael Whitacker Gerotti, Renata Marques Vianna & Reginaldo José Donatelli To cite this article: Guilherme Sementili-Cardoso, Fernanda Gonçalves Rodrigues, Rafael Martos Martins, Raphael Whitacker Gerotti, Renata Marques Vianna & Reginaldo José Donatelli (2018) Variation among vocalizations of Tarabamajor (Aves: Thamnophilidae) subspecies, Studies on Neotropical Fauna and Environment, 53:2, 120-131, DOI: 10.1080/01650521.2017.1414983 To link to this article: https://doi.org/10.1080/01650521.2017.1414983 View supplementary material Published online: 26 Dec 2017. Submit your article to this journal Article views: 72 View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=nnfe20 STUDIES ON NEOTROPICAL FAUNA AND ENVIRONMENT 2018, VOL. 53, NO. 2, 120–131 https://doi.org/10.1080/01650521.2017.1414983 ORIGINAL ARTICLE Variation among vocalizations of Taraba major (Aves: Thamnophilidae) subspecies Guilherme Sementili-Cardoso a,b, Fernanda Gonçalves Rodriguesa,b, Rafael Martos Martinsa,b, Raphael Whitacker Gerottia,b, Renata Marques Viannaa,b and Reginaldo José Donatelli a aLaboratório de Ornitologia, Faculdade de Ciências, Universidade Estadual Paulista “Júlio de Mesquita Filho”, Bauru, Brazil; bPrograma de Pós-Graduação em Ciências Biológicas (Zoologia), Instituto de Biociências, Universidade Estadual Paulista “Júlio de Mesquita Filho”, Botucatu, Brazil ABSTRACT ARTICLE HISTORY Geographical variation of bird vocalizations may be related to factors influencing sound produc- Received 26 September 2016 tion and sound propagation. If birds, e.g. the Great Antshrike (Taraba major), produce vocaliza- Accepted 4 December 2017 tions that develop normally in the absence of learning, these variations may reflect evolutionary KEYWORDS divergence within species. In this case, vocal variation could be influenced by habitat structure, Suboscine; since abiotic features and vegetal cover affect sound propagation through environment. Selective isolation-by-distance; vocal pressures may be acting on populations in different ways, which could culminate in a process of variation; bioacoustics; speciation. Thus, we searched for structural variation of Great Antshrike vocalizations between acoustic adaptation subspecies and sought for relationships between these vocal variation and environmental struc- ture. We found variations in frequency and time features of vocalizations among subspecies, which are correlated to latitude, elevation and climate. We also observed an increase in vocal differences along with an increase in distances between individuals, which could reflect isolation of subspecies and the vocal adaptation to different environments. Introduction Thamnophilidae (Touchton et al. 2014), and many The current knowledge about vocal variation in birds is studies have shown that vocal variation occurs within mostly restricted to oscine passerines (suborder suboscine species, as in Furnariidae (Lindell 1998), Passeri). In this group, learning and auditory feedback Tyrannidae (Sedgwick 2001; Lovell & Lein 2004; Ríos exert great influence on vocal development (Marler & Chelén et al. 2005; Lein 2008) and Cotingidae Tamura 1964; Marler 2000). Thus, vocal variation may (Fitzsimmons et al. 2008). In this case, vocal variation be assigned to cultural differences that occur among may be an indicator of allopatric divergence occurring different populations and it may be derived from learn- within the species, which is an initial step in the pro- ing deviations that occur over generations (Podos & cess of speciation (Seddon 2005). Warren 2007). In contrast, suboscine passerines pro- Since vocal divergence among populations could duce vocalizations in which learning exerts little or no indicate evolutionary changes, the pattern of variation influence on their ontogeny (Kroodsma 1984; could be a reflection of the distance among populations Kroodsma & Konishi 1991; Touchton et al. 2014). (Koetz et al. 2007). Few studies have focused on the These innate vocal signals tend to be relatively simple vocal variation of suboscine birds along geographical and stereotyped (Tobias et al. 2012), with little evi- distances, whether in small parts of the species distri- dence of intraspecific variation (Lindell 1998; Bard bution (Payne & Budde 1979; Lein 2008) or across all et al. 2002; Seddon & Tobias 2006; Tobias et al. of their areas of occurrence (Lovell & Lein 2013). Other 2010). In this case, vocal variation may putatively studies correlated the vocal variation in suboscines to reflect the genetic differences that occur among popu- environmental structure (Ippi et al. 2011) and to dif- lations of the same species (Kroodsma 1984, 1989; ferent subspecies that varied morphologically and Kroodsma & Konishi 1991). This paradigm regarding genetically (Paxton et al. 2008). The same kind of the development of suboscine vocalization is based on variation may occur in Great Antshrike subspecies, Tyrannidae (Kroodsma 1984, 1985, 1989) and making them diagnosable through the acoustic features CONTACT Guilherme Sementili-Cardoso [email protected] Supplemental data for this article can be accessed here. © 2017 Informa UK Limited, trading as Taylor & Francis Group Published online 26 Dec 2017 STUDIES ON NEOTROPICAL FAUNA AND ENVIRONMENT 121 of their vocalizations. Isler et al. (1998) argued that patterns of sound. This mechanism of sound percep- even a small number of vocal characteristics could tion is distant from music since musical melody exhibit differences between pairs of species. depends on fine spectral resolution while bird vocal Suboscine birds have a high number of species in signals seems to employ pitch as an auxiliary tool in the Neotropics (Irestedt et al. 2004), and the the communication process (Shannon 2016). Thamnophilidae are within this group of birds. The For the same reason, we used the word ‘element’ to Great Antshrike (Taraba major (Vieillot 1816)) is a designate the smallest sound units that constituted the thamnophilid species that has a wide distribution, vocalization, instead of ‘note.’ All of these elements, from northern Argentina to central Mexico (Ridgely grouped into a sound unit, were called a ‘syllable’ & Tudor 1994). It inhabits the dense undergrowth of (Marler & Slabbekoorn 2004). The organization of these shrubs in riparian forests, savanna, and secondary for- syllables in time sets was called a ‘motif’ (not ‘phrase’ or ests, and also edges and clearings of tropical rain for- ‘sentence’) because this term included syntactical organi- ests (Zimmer & Isler 2003). It is a sedentary bird that zations at various levels of complexity (Berwick et al. has shy habits and that moves discreetly in the envir- 2011). Therefore, a vocalization was composed of sets of onment, but it has a very conspicuous vocalization motifs arranged in a temporal sequence. (Ridgely & Tudor 1994). Up to now, there are no reports on the vocal behavior of this species. Since File survey vocalizations are related to several aspects of reproduc- tion of thamnophilid birds, it is crucial to characterize We gathered vocalizations that were previously these emissions and to understand factors that may recorded by several persons. Due to the wide distribu- shape the evolution of this behavior across the species. tion of the species, recordings were obtained from the Bioacoustics is an important tool for population studies, following bioacoustics libraries: Xeno-Canto website and it contributes to the resolution of issues in ornithology (www.xeno-canto.com), Wiki Aves website (www. (Laiolo 2010), such as the existence of vocal variations wikiaves.com.br) and Macauley Library (Cornell Lab within a species. Thus, the study of the vocalization of a of Ornithology, Cornell University). We measured species with a wide distribution, such as T. major, allows vocal features from one type of vocalization among the recording of possible differences. If such differences are the sound files, which is known as ‘loudsong’ (Willis distinct enough, they might serve as a taxonomic tool 1967). The term ‘loudsong’ refers to antbirds’ vocaliza- where case birds have innate vocalizations. The under- tions since these vocal emissions differ from the tradi- standing of the significance of these vocal variations is tional sense of song (Zimmer & Isler 2003). It is obstructed by the lack of quantitative analysis. We common in many antbirds that males and females hypothesized that vocal variation occurs among Great produce loud vocalizations as solo or as duets. Antshrike subspecies, and that it is related to differences Generally, this vocalization consists of multiple ele- in habitat structure, such as temperature, precipitation, ments or syllables emitted in a stereotypic sequence vegetation cover and elevation. Therefore, our objective is (Seddon & Tobias 2006). to search for vocal variations in the acoustic structure of The ‘loudsong’ vocalization of Great Antshrike has Great Antshrike vocalizations among subspecies of the two different motifs, each one with a single type of complex and to seek for relationships between these pos- syllable, which was classified according to the mor- sible variations and