DOI: 10.5061/dryad.tqjq2bw05
title: Data from: Global plant-frugivore trait matching is shaped by climate and biogeographic history

description: Species interactions are influenced by the trait structure of local
 multi-trophic communities. However, it remains unclear whether mutualistic
 interactions, in particular, can drive trait patterns at the global scale,
 where climatic constraints and biogeographic processes gain importance.
 Here we evaluate global relationships between traits of frugivorous birds
 and palms (Arecaceae), and how these relationships are affected, directly
 or indirectly, by assemblage richness, climate and biogeographic history.
 We leverage a new and expanded gape size dataset for nearly all avian
 frugivores, and find a positive relationship between gape size and fruit
 size, that is, trait matching, which is influenced indirectly by palm
 richness and climate. We also uncover a latitudinal gradient in trait
 matching strength, which increases towards the tropics and varies among
 zoogeographic realms. Taken together, our results suggest trophic
 interactions have consistent influences on trait structure, but that
 abiotic, biogeographic and richness effects also play important, though
 sometimes indirect, roles in shaping the functional biogeography of
 mutualisms.
description: <em>Modified from: McFadden et al. Global plant-frugivore
 trait matching is shaped by climate and biogeographic history.
 </em>Ecology Letters<em> (in press).</em>
 To assemble this dataset of trait measurements for avian
 frugivores, we compiled a dataset of beak measurements taken from
 wild-caught and released individuals, as well as specimens accessed in
 numerous museums and research collections worldwide (Tobias et al. 2021).
 We defined frugivores as those species with a diet containing 50% or more
 fruit, and only kept species matching this criterion. We attempted to
 measure at least two males and two females of each avian frugivore
 species, with the final dataset containing measurements from 12925
 individuals and a total of 1129 species. For beak volume and diet traits
 we used data from Pigot et al. (2020) and Tobias et al. (2021). To
 quantify beak volume (n = 1129 spp.), we multiplied beak length, measured
 from the tip of the beak along the culmen to the base of the skull, with
 beak width and beak depth, both measured at the anterior edge of the
 nostrils (units = mm3). To quantify avian frugivore
 gape size (previously termed ‘gape width’ or ‘beak width’ in some
 studies), we used data from Pigot et al. (2016), Bender et al. (2018) and
 Hanz et al. (2019), and also collected previously unpublished measurements
 on thousands of additional individuals. We defined gape size as the
 horizontal width of the beak measured between the points at which the
 upper and lower mandibles meet. Unlike standard beak measurements, such as
 those in Tobias et al. (2021), this global dataset of gape size is unique
 to McFadden et al. (in revison). We include gape size data in two ways.
 First, as species averages used in our models, and second, by providing
 the underlying data from all specimens and wild-caught individuals along
 with metadata on source, collection locality and measurer. 
 <br>References:
 Bender, I.M.A. et al. 2018. Morphological trait matching shapes
 plant–frugivore networks across the Andes. Ecography, 41,
 1910–1919. Hanz, D.M. et al. 2019. Functional and
 phylogenetic diversity of bird assemblages are filtered by different
 biotic factors on tropical  mountains. Journal of Biogeography, 46,
 291–303. McFadden et al. Global plant-frugivore trait
 matching is shaped by climate and biogeographic history. Ecology Letters.
 In revision. Pigot, A.L. 2016. Quantifying species
 contributions to ecosystem processes: A global assessment of functional
 trait and phylogenetic metrics across avian seed-dispersal networks.
 Proccedings of the Royal Society B, 283, 20161597.
 Pigot, A.L. et al. 2020. Macroevolutionary convergence connects
 morphological form to ecological function in birds. Nature Ecology and
 Evolution, 4, 230–239. Tobias, J.A. et al. 2021.
 AVONET: Morphological, ecological and geographical data for all birds.
 Ecology Letters.