Turnover of bird species along the Nullarbor barrier: insights from taxonomic, phylogenetic and functional beta diversity

1. Bird occurrence data retrieved from the BirdLife Australia Atlas (https://birdata.birdlife.org.au/). BirdLife Australia’s Atlas data are collected by skilled birdwatchers at sites they choose, with exact coordinates recorded for each survey. Bird surveys are carried out during the austral breeding season using the “2-ha, 20 min” method. This census method involves searching for birds in a two-hectare plot for 20 minutes. During this period, the volunteer records the geographical reference at the centre of their plot and all birds seen or heard in their survey area, including those flying overhead. Our dataset included sampling plots distributed on both sides of the Nullarbor Plain. This dataset was employed to conduct the diversification analyses. 2. Matrices of beta diversities (phylogenetic and functional), environmental dissimilarities and geographic distances used as input in the analyses.