For the first time, scientists have mapped the evolutionary relationships of every known bird species. Professor Emily Jane McTavish and her colleagues at the Cornell Lab of Ornithology have constructed a comprehensive evolutionary tree encompassing all 10,239 known bird species. This groundbreaking achievement combines data from nearly 300 studies conducted between 1990 and 2024, along with additional curated data on another 1,000 species. The resulting database is designed to be easily shared and updated as new research becomes available. "People are passionate about birds, and there's a wealth of ongoing scientific work dedicated to them," McTavish stated. "By synthesizing all this data, we've created a unified resource that can be accessed and utilized by researchers worldwide." The team's methodology and findings are detailed in a recent paper published in the Proceedings of the National Academy of Sciences. The evolutionary map is expected to provide valuable insights into bird evolution and ecology, helping to address diverse research questions. Moreover, the techniques developed for this project can be applied to other organisms, including animals and plants, enhancing our understanding of life’s complex relationships. The project began about four years ago when Eliot Miller, then associated with the Cornell Lab of Ornithology, approached McTavish. Miller noted that numerous evolutionary studies on birds are published annually, but their findings often fail to make it into subsequent research or broader applications. This gap motivated the collaboration. "Each year, many bird phylogenetic studies emerge, often with significant implications for taxonomy and our understanding of ancestral traits," Miller said. "Our goal is to bridge this gap so that the results of these studies are more effectively integrated into future research." Despite never having met Miller before this project, McTavish found the endeavor aligned perfectly with her ongoing work. She has spent nearly a decade developing software for the Open Tree of Life (OpenTree) project, while the Cornell Lab is renowned for its expertise in ornithology and the development of popular birding apps like Merlin and Ebird. "The lab's focus on bird biology and technology, combined with my background in software for consolidating evolutionary trees, made this a natural fit," McTavish explained. OpenTree is a collaborative initiative that aims to create an accurate and comprehensive evolutionary tree for all named species on Earth. It operates on a wiki-like platform, enabling users to manually upload data and update the tree's relationships. As new insights into species relationships arise, users can add this information, ensuring the Tree of Life remains up-to-date and reflective of the latest scientific knowledge. Advances in genome sequencing have contributed to the rapid expansion of the Open Tree of Life, which now includes over 2.5 million species. To manage this influx of data, McTavish and her collaborators are developing software to automate the updating process. This automated system will help maintain the tree's accuracy and relevance. "We are constantly refining our tools to handle the vast amount of new data being generated," McTavish said. "The bird species synthesis is a significant milestone in achieving a fully integrated and representative Tree of Life." This comprehensive bird evolutionary tree not only fills a critical gap in the Open Tree project but also serves as a robust foundation for advancing the field of evolutionary biology. The accessibility and dynamic nature of the database promise to spur new research and deepen our understanding of avian diversity and evolution.