Behaviour 2019
Search
Vocal mimicry sequences of Albert’s lyrebirds are socially transmitted and enhance acoustic contrast
Fiona Backhouse1, Anastasia H. Dalziell1,2,3,4,5, Robert D. Magrath6, Justin A. Welbergen1. 1The Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia; 2Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia; 3Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, Cornell University, Ithaca, NY, United States; 4Macaulay Library, Cornell Lab of Ornithology, Cornell University, Ithaca, NY, United States; 5Center for Conservation Bioacoustics, Cornell Lab of Ornithology, Cornell University, Ithaca, NY, United States; 6Research School of Biology, The Australian National University, Canberra, ACT, Australia

Many animals communicate in hierarchically organised sequences of vocal units, yet little is known about the drivers of sequence structures. Here we test for the social transmission and organization of sequences of vocal mimicry in male Albert’s lyrebirds. We found that individuals organised mimetic units into highly stereotyped sequence structures comprising on average 15 sounds from seven heterospecifics. In addition, these sequence structures were shared within and to a lesser extent among populations. Furthermore, we found that, across the species, sequences were organised such that they increased acoustic contrast between mimetic units, suggesting that lyrebirds structure their mimetic sequences to enhance perceptions of their repertoire complexity. This study indicates that higher levels of organisation of vocalisations can be socially transmitted, and suggests that the order in which vocal units are presented can be functionally significant.