The acoustic repertoire of the Atlantic Forest Rocket Frog and its consequences for taxonomy and conservation (Allobates, Aromobatidae)

Abstract

The use of acoustic signals is a common characteristic of most anuran species to mediate intraspecific communication. Besides many social purposes, one of the main functions of these signals is species recognition. For this reason, this phenotypic trait is normally applied to taxonomy or to construct evolutionary relationship hypotheses. Here the acoustic repertoire of five populations of the genus Allobates from the Brazilian Atlantic Forest are presented for the first time, on a vulnerable to extinction Neotropical taxon. The description of males’ advertisement and aggressive calls and a female call emitted in a courtship context are presented. In addition, the advertisement calls of individuals from distinct geographical regions were compared. Differences in frequency range and note duration may imply in taxonomic rearrangements of these populations, once considered distinct species, and more recently, proposed as a single species, Allobates olfersioides. Calls of the male from the state of Rio de Janeiro do not overlap spectrally with calls of males from northern populations, while the shorter notes emitted by males from Alagoas also distinguishes this population from the remaining southern populations. Therefore, it is likely that at least two of the junior synonyms should be revalidated. Similarities among male advertisement and female calls are generally reported in other anuran species; these calls may have evolved from a preexisting vocalization common to both sexes. Male aggressive calls were different from both the male advertisement and female calls, since it was composed by a longer and multi-pulsed note. Aggressive and advertisement calls generally have similar dominant frequencies, but they have temporal distinctions. Such patterns were corroborated with the Atlantic Forest Rocket Frogs. These findings may support future research addressing the taxonomy of the group, behavioral evolution, and amphibian conservation.

Amphibians of Santa Teresa, Brazil: the hotspot further evaluated

“…Rödder et al (2007) listed Allobatescf.olfersioides following Verdade and Rodrigues (2007) who placed A.capixaba as synonym of A.olfersioides . Studies on Allobates indicate A.capixaba is a valid taxon (e.g., Bokermann 1967; Forti et al 2017), which agrees with Almeida et al (2011). Fieldwork should be conducted in the vicinities of Santa Teresa to confirm the presence of Brachycephalusalipioi .…”

Functional traits explain amphibian distribution in the Brazilian Atlantic Forest

“…In addition, we conducted acoustic and visual nocturnal/diurnal amphibian survey (Crump & Scott Jr., 1994;Zimmerman, 1994) in 11 Protected Areas (PAs), from southern to the northeastern Brazil (see Appendix S1, Figure 1.2).We followed Frost (2019) for the amphibian nomenclature with exception of the species synonymized as Allobates olfersioides which we consider to be distinct species (A. olfersioides, A. alagoanus and A. capixaba see Forti, Silva, & Toledo, 2017). In addition, we conducted acoustic and visual nocturnal/diurnal amphibian survey (Crump & Scott Jr., 1994;Zimmerman, 1994) in 11 Protected Areas (PAs), from southern to the northeastern Brazil (see Appendix S1, Figure 1.2).We followed Frost (2019) for the amphibian nomenclature with exception of the species synonymized as Allobates olfersioides which we consider to be distinct species (A. olfersioides, A. alagoanus and A. capixaba see Forti, Silva, & Toledo, 2017).…”

“…We included species occurrence records available through the Global Biodiversity Information Facility (GBIF: http://www.gbif.org), and added range maps of each species from the IUCN Red List of Threatened Species (IUCN, 2017: http://www.iucnr edlist.org/techn ical-docum ents/spati al-data). In addition, we conducted acoustic and visual nocturnal/diurnal amphibian survey (Crump & Scott Jr., 1994;Zimmerman, 1994) in 11 Protected Areas (PAs), from southern to the northeastern Brazil (see Appendix S1, Figure 1.2).We followed Frost (2019) for the amphibian nomenclature with exception of the species synonymized as Allobates olfersioides which we consider to be distinct species (A. olfersioides, A. alagoanus and A. capixaba see Forti, Silva, & Toledo, 2017).…”

Calls of Boana latistriata (Caramaschi & Cruz, 2004) (Amphibia, Anura, Hylidae), an endemic tree frog from the State of Minas Gerais, Brazil

“…Vocalization plays an essential role during the reproductive period of anurans, being species-specific and constituting a pre-zygotic mechanism of reproductive isolation (Duellman and Trueb 1994, Wells 2007). This makes bioacoustical data useful for studying topics such as conservation (Laiolo 2010, Forti et al 2017), taxonomy (Hepp and Carvalho-e-Silva 2011, Carvalho and Giaretta 2013, Rivadeneira et al 2018), social interaction (Giasson and Haddad 2006), and evolution (Robillard et al 2006, Goicoechea et al 2010). Amongst the different anuran call types, advertisement calls have the highest value in taxonomy (Köhler et al 2017).…”