Singing in the rain forest: how a tropical bird song transfers information

• Published in: PloS one 2008-02, Vol.3 (2), p.e1580-e1580
• Main Authors: Mathevon, Nicolas, Aubin, Thierry, Vielliard, Jacques, da Silva, Maria-Luisa, Sebe, Frédéric, Boscolo, Danilo
• Format: Article
• Language: English
• Subjects: Acoustic properties; Acoustics; Animal Communication; Animals; Basileuterus leucoblepharus; Behavioral sciences; Birds; Coding; Communication; Communications networks; Communications systems; Decoding; Dialects; Ecological effects; Ecology; Ecology/Behavioral Ecology; Ecosystem; Environmental aspects; Evolution; Evolution (Biology); Evolutionary Biology/Animal Behavior; Experiments; Forests; Hypotheses; Information management; Information processing; Male; Males; Mating behavior; Natural selection; Noise; Phonetics; Propagation; Rain; Rain forests; Rainforests; Singing; Social behavior; Song; Songbirds; Sound; Species; Tropical Climate; Tropical forests; Vocalization, Animal
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0001580

How information transmission processes between individuals are shaped by natural selection is a key question for the understanding of the evolution of acoustic communication systems. Environmental acoustics predict that signal structure will differ depending on general features of the habitat. Social features, like individual spacing and mating behavior, may also be important for the design of communication. Here we present the first experimental study investigating how a tropical rainforest bird, the white-browed warbler Basileuterus leucoblepharus, extracts various information from a received song: species-specific identity, individual identity and location of the sender. Species-specific information is encoded in a resistant acoustic feature and is thus a public signal helping males to reach a wide audience. Conversely, individual identity is supported by song features susceptible to propagation: this private signal is reserved for neighbors. Finally, the receivers can locate the singers by using propagation-induced song modifications. Thus, this communication system is well matched to the acoustic constraints of the rain forest and to the ecological requirements of the species. Our results emphasize that, in a constraining acoustic environment, the efficiency of a sound communication system results from a coding/decoding process particularly well tuned to the acoustic properties of this environment.