DOI: 10.5061/dryad.dfn2z351n
title: Global impacts of climate change on avian functional diversity

description: Climate change is predicted to drive geographical range shifts, leading to
 fluctuations in species richness worldwide. However, the effect of these
 changes on functional diversity remains unclear, in part because
 comprehensive species-level trait data are generally lacking at global
 scales. Here we use morphometric and ecological traits for 8268 bird
 species to estimate the impact of climate change on avian functional
 diversity (FD). We show that future bird assemblages are likely to undergo
 substantial shifts in trait structure, with a magnitude of change greater
 than predicted from species richness alone, and a direction of change
 varying according to geographical location and trophic guild. For example,
 our models predict that FD of insect predators will increase at higher
 latitudes with concurrent losses at mid-latitudes, whereas FD of seed
 dispersing birds will fluctuate dramatically across the tropics. Our
 findings highlight the potential for climate change to drive
 continental-scale shifts in avian functional diversity with implications
 for ecosystem function and resilience.
description: These data comprise the raw data and results of the
 article: Stewart et al. (2021) Global impacts of climate change on avian
 functional diversity. Ecology Letters (in press). The
 methods used to generate these data are fully described in main text and
 supplementary methods of the paper, and all R code is provided below.
 Please see the usage notes for details. Code to
 reproduce the species distribution models from Hof et al. (2018), which we
 used in our analyses, is available
 at: https://github.com/christianhof/BioScen1.5_SDM
description: All data and code are contained within subfolders of a compressed
 (zipped) folder, as shown below. Please see the three
 metadata files within the data subfolders (metadata_dispersal_data.txt,
 metadata_raw_data.txt, and metadata_results_data.txt) for all data file
 descriptions, variable descriptions and other usage information.
 Code 1. Dispersal model -
 Contains all code to model dispersal distances for each species.
 CODE_NonVolant - model for flightless
 species CODE_Volant - model for flying
 species _MACOSX - versions for Mac OS X
 2. Creating presence absence matrices -
 Contains all code to go from the SDM's
 (https://github.com/christianhof/BioScen1.5_SDM) to the presence-absence
 matrices. Threshold the projected
 distributions Clip projected distributions by
 modelled dispersal Summarise projections into
 presence-absence matrix Cleaning presence-absence
 matrices 3. Functional
 diversity analyses - Contains all code to go from the presence-absence
 matrices to the final results. The R scripts within were run in numerical
 order. 1. Traits dendro and PCA
 2. Create_no_dispersal_scenario 3.
 Calculate SR FD and FRic 4. Create subsets for
 hypervolumes 5. Hypervolume code and subsets -
 contains all code and data necessary to perform the Gaussian hypervolume
 calculations. We recommend running this in parallel on an HPC. 
 6. Binding hypervolume results together 7.
 Merge results dataframes and calculate metric changes
 8. Create figures 
 Data Dispersal_model_data
 metadata_dispersal_data.txt - contains all metadata
 for the dispersal dataset 
 Raw_data metadata_raw_data.txt - contains
 all metadata for the raw data 
 Results_data metadata_results_data.txt
 - contains all metadata for the results datasets