The newly described Araguaian river dolphins, Inia araguaiaensis (Cetartyodactyla, Iniidae), produce a diverse repertoire of acoustic signals
- Published
- Accepted
- Subject Areas
- Animal Behavior, Biodiversity, Ecology, Zoology, Freshwater Biology
- Keywords
- boto, behavior, acoustic communication, mother-calf pairs, non-linear phenomena
- Copyright
- © 2018 Melo-Santos et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. The newly described Araguaian river dolphins, Inia araguaiaensis (Cetartyodactyla, Iniidae), produce a diverse repertoire of acoustic signals. PeerJ Preprints 6:e26962v1 https://doi.org/10.7287/peerj.preprints.26962v1
Abstract
The recent discovery of the Araguaian river dolphin (Inia araguaiaensis) highlights how little we know about the diversity and biology of river dolphins. In this study, we described the acoustic repertoire of this newly discovered species in concert with their behaviour in free-ranging, human-habituated individuals. We analysed 393 signals that we classified into 13 types of tonal sounds (n=15) and 66 types of pulsed calls (n=378). The most common sounds were short two-component calls. Thirty-five percent (n=140) of these calls were emitted by calves as they reunited with their mothers suggesting a key role in mother-calf communication. Our findings show that the acoustic repertoire of river dolphins is far from simple. Furthermore, the calls described here are similar in acoustic structure to those produced by social delphinids, such as orcas and pilot whales. Uncovering the context in which these signals are produced may help understand the social structure of this species and contribute to our understanding of the evolution of acoustic communication in whales.
Author Comment
The present paper was part of my PhD thesis and we intend to submit as a peer-reviewed paper after getting feedback from the preprint version. The study focus on the acoustic repertoir of a newly described species of river dolphin, Inia araguaiaensis, endemic to the Tocantins River in Brazil. This is the most human-impacted riverine system in the Amazon, so acquiring biological information on this unknown species in urgent. As acoustic communication is a key factor cetacean biology, understanding how these animals communicate in their environment is vital to understand how human activities can impact their behavior and for their conservation.
Supplemental Information
Short two-component-calls produced by a calf of Araguaian boto
Short two-component-calls produced by a calf of Araguaian boto while contacting its mother, at the moment the calf was rubbing its head on the mather's belly
Short calls produced by an Araguaian boto
Short call produced by an Araguaian boto while interacting with humans at the market of Mocajuba, Tocantins River, Brazil
Long call with subharmonics produced by an Araguaian boto
Long call with subharmonics produced by an Araguaian boto while interacting with humans at the market of Mocajuba, Tocantins River, Brazil
Short call with subharmonics produced by an Araguaian boto
Short call with subharmonics produced by an Araguaian boto while interacting with humans at the market of Mocajuba, Tocantins River, Brazil
Whistle produced by an Araguaian boto
Whistle produced by an Araguaian boto while interacting with humans at the market of Mocajuba, Tocantins River, Brazil
Long two-component call produced by an Araguaian boto
Long two-component call produced by an Araguaian boto while interacting with humans at the market of Mocajuba, Tocantins River, Brazil
Araguaian boto calf videos url's
This is a link to a dropbox folder containing videos of an Araguaian boto female calf producing short two-component calls after reuniting with her mother, the call emission is followed by bubble streams, identifying the vocalizing animal. As the files are too long for uploading on Peer J database I am providing the link through this document