Six decades of change across all North American bird interaction networks

Global changes are altering patterns of biodiversity on Earth and species interactions are essential for maintaining this biodiversity. Understanding how interaction networks are shifting in structure and function across time and space provides important insights about the underlying drivers of biodiversity, ultimately improving predictions across scales. Yet lack of interaction data across broad geographic areas and taxa has hindered progress. Birds are ideal taxa to address this shortfall because they are involved in numerous types of positive, negative, and neutral interactions that provide essential ecosystem functions and services. Here we leverage AvianMetaNetwork, a novel and comprehensive database of avian interactions in North America, to quantify six types of network layers using 13,762 pairwise interactions among 687 species from the North American Breeding Bird Survey. Using network modelling, we quantify six decades of bird interaction network shifts, at regional to continental scales. We find that turnover of species’ abundance since 1970 accounts for the vast majority of changes in trophic and non-trophic interaction networks, and that this turnover results in large changes in network structure and function, especially in eastern North America. Increased human pressures over multiple decades are highly correlated with these trends (especially human intrusion into habitat, infrastructure, and pollution), suggesting that humans are driving these changes. With this metanetwork, we uncovered more than a half century of previously undocumented shifts in the structure of all avian networks at a continental scale, with large implications for the functioning of bird communities and the ecosystems that rely on them.