title: A rhythm landscape approach to the developmental dynamics of birdsong.
abstract: Unlike simple biological rhythms, the rhythm of the oscine bird song is a learned time series of diverse sounds that change dynamically during vocal ontogeny. How to quantify rhythm development is one of the most important challenges in behavioural biology. Here, we propose a simple method, called 'rhythm landscape', to visualize and quantify how rhythm structure, which is measured as durational patterns of sounds and silences, emerges and changes over development. Applying this method to the development of Bengalese finch songs, we show that the rhythm structure begins with a broadband rhythm that develops into diverse rhythms largely through branching from precursors. Furthermore, an information-theoretic measure, the Jensen-Shannon divergence, was used to characterize the crystallization process of birdsong rhythm, which started with a high rate of rhythm change and progressed to a stage of slow refinement. This simple method provides a useful description of rhythm development, thereby helping to reveal key temporal constraints on complex biological rhythms.
authors.affiliation: Department of Complex Systems Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan Laboratory for Biolinguistics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan sasahara@nagoya-u.jp.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Sasahara
authors.affiliation: Department of Psychology, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA.
authors.forename: Ofer
authors.initials: O
authors.lastname: Tchernichovski
authors.affiliation: Laboratory for Biolinguistics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Takahasi
authors.affiliation: Laboratory for Biolinguistics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Faculty of Health Sciences, Nihon Institute of Medical Science, 1276 Shimogawara, Moroyama-machi, Iruma-gun, Saitama 350-0435, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Laboratory for Biolinguistics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Department of Life Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Okanoya
mesh_terms: D000818:Animals; D046369:Finches / Q000502:physiology*; D010507:Periodicity; D014828:Vocalization, Animal / Q000502:physiology*
keywords: band formation dynamics; biological rhythms; birdsong; rhythm landscape