DOI: 10.5061/dryad.rn8pk0p8b
title: Data from: Multiple factors affect the evolution of repertoire size across birds

description: Changes in signaling repertoires across species allow for insight into the
 macroevolutionary forces that control signaling systems. Signaling systems
 are theorized to be affected by both the social and ecological
 environments of species. With respect to social variables, increased
 social complexity is thought to lead to increased vocal complexity.
 Although ecology can affect signaling systems in numerous ways, one
 potential effect of ecology is that more cluttered habitats should lead to
 greater reliance on non-visual (e.g. vocal) signals. To test these
 concepts on a macroevolutionary scale, we compiled a large dataset of
 avian vocal repertoires. We amassed vocal repertoires for 821 species of
 birds and for many of these species categorized their vocalizations into
 usage categories (e.g. alarm, contact). To analyze the social and
 ecological forces that act on repertoire evolution, we incorporated
 datasets with several social variables (e.g. cooperative breeding and
 length of social bond), and included data on the habitat and foraging
 behaviors of species within the dataset. We used Bayesian phylogenetic
 analysis to test for potential relationships within the data. We found
 that cooperative breeding was a significant predictor of larger repertoire
 size in birds; we also find several, more targeted effects. For instance,
 foraging strata affected repertoire size and repertoire composition. In
 sum, we find considerable evidence that social features affect repertoire
 size while certain ecological variables have more targeted effects on
 vocal repertoires.
description: To develop the dataset we relied heavily on data within the Birds
 of North America (BNA)(2018). We follow Bradbury and Vehrencamp (1998)’s
 definition of functional repertoire size to compile repertoires. Briefly,
 a functional repertoire represents sounds associated with distinct
 behavioral contexts. The functional repertoires for virtually every
 species from BNA is included in the current dataset, and paired with
 previously published data from Handbook of Australian, New Zealand, and
 Antarctic Birds (HANZAB)(1998) and the primary literature (Leighton,
 2017). Both of the secondary sources (BNA and HANZAB) are curated volumes
 of species information for their respective geographic locations. For
 species from the primary literature, journal articles focused specifically
 on defining vocal repertoires were collected, and vocalizations given in
 specific behavioral contexts were described as a functional repertoire; in
 addition to the species identified from studies in the primary literature,
 species from HANZAB and BNA closely related to primary literature were
 added (see Leighton (2017) for details). Comparative analyses (see below)
 on overall repertoire size were performed on all species; given the
 differences between sources in repertoire size, we included data source as
 a fixed factor in all models to control for differences between the
 sources. We therefore control for differences in repertoire size between
 primary and secondary sources.