ASRD · Acoustic species recognition in delphinids
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-07-01 → 2018-06-30
- EU contribution
- €195,455
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Acoustic species recognition in delphinids
Species recognition is a major function of animal calls and many animals use just one or a few calls to accomplish this goal. In animals that produce many different calls, it is often unclear whether all of these carry information about species identity. Dolphins produce whistles that are used for social communication and could be expected to carry information about species identity. However, every species produces many different kinds of whistles and the whistles of different species often sound similar to one another. Because of this, it is not clear whether dolphins are using whistles to communicate species identity and if they are, what characteristics of whistles carry this information. These are interesting questions in the light of understanding dolphin communication, but they also have applied aspects. Dolphins spend a large amount of time under water where they cannot be seen and many species are found at great distances offshore or in harsh environments where it is difficult to find and study them. Many dolphins are very vocal and so to overcome these challenges, researchers use passive acoustic methods to study them. Many underwater acoustic recordings are made without associated visual observations and so it is important to be able to identify species based on their calls. This has proven to be difficult because each species produces so many different kinds of whistles and because different species can sound very similar to one another. Understanding whether and how dolphins are using whistles to communicate species identity will help scientist to develop more accurate tools for identifying their sounds to species in acoustic recordings. The overall objective of this work was to investigate whether species information is carried in dolphin whistles using three approaches: 1) by comparing the whistle repertoires of six different dolphin species, 2) by playing whistles of different species to bottlenose dolphins and observing behavioural reactions, and 3) by playing whistles of different species to bottlenose dolphins and looking at changes in heart rate. Conclusions from these work packages are that dolphins share many whistle-types across species but also produce whistle-types that are unique to individual species. These unique whistle-types may carry species specific information. Dolphins exhibited behavioural reactions to whistles produced by different species but no significant changes in heart rate. This shows that dolphins recognize and react to differences in whistles produced by different species and that these reactions are not just driven by the autonomic nervous system.
Data: CORDIS, © European Union
Project objective
Species recognition is a major function of animal communication signals. A lack of recognition can carry fitness costs due to failed breeding attempts and other challenges. Individual recognition can also have fitness implications, as the ability to recognize individuals is important for mother-offspring interactions and in species that form alliances to improve their fitness. Both species and individual identity can be encoded in signal parameters, however species recognition could be compromised by individual recognition when the latter requires large individual signal diversity. Dolphins use whistle modulation patterns for individual recognition, but if and how they use whistles for species recognition is unknown. We propose to study the interaction between individual and species recognition in dolphins. We will do this by investigating whether captive bottlenose dolphins pay attention to species information when listening to whistles and which whistle parameters carry species-specific information. Our main objectives are to a) record and analyse whistles of three species, bottlenose (Tursiops truncatus), common (Delphinus delphis), and Atlantic spotted (Stenella frontalis) dolphins to compare their use of whistle modulation patterns and establish a catalogue of shared whistles, b) test how bottlenose dolphins react to a whistle that is similar to a signature whistle of a close associate but is produced by another species, and c) manipulate whistles digitally to explore the boundaries of species and/or individual recognition in a habituation/dishabituation paradigm. Our results will be significant for the development of species identification algorithms used to analyze acoustic data. Understanding the parameters that dolphins use for species recognition will allow researchers to create more accurate classification algorithms. Improved algorithms will provide the capability to more effectively evaluate and mitigate impacts of anthropogenic activities on dolphins.
Original text from CORDIS.
Participants
- THE UNIVERSITY COURT OF THE UNIVERSITY OF ST ANDREWS · ST ANDREWSCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union