Ithaca, N.Y.—The Cornell Lab of Ornithology today announced the release of a new online tool for studying biodiversity and the evolutionary relationships among birds: the illustrated Birds of the World Phylogeny Explorer. Available on Birds of the World, the Phylogeny Explorer offers a captivating experience for exploring avian evolution, discovering closely related species, and grasping the timescales at which they evolved.
Understanding avian ancestry, what scientists call phylogeny, is a fundamental aspect that underpins most ornithology research. But with more than 11,000 bird species in the world, organizing the available phylogenetic trees into a single synthetic depiction, and keeping it current, has long challenged ornithologists. The Birds of the World Phylogeny Explorer uniquely addresses these challenges by staying current with the latest research.
"This tool combines centuries of bird research with computational tools to create an engaging and interactive resource that tells the story of how birds evolved," says Dr. Eliot Miller, researcher with American Bird Conservancy and one of the project leads.
"New evolutionary relationships are constantly revealed," Miller explains. "We will release an updated Phylogeny Tool annually, thus providing a comprehensive phylogenetic dataset that syncs with current taxonomy.”
“This tool greatly benefits science,” says Dr. Pam Rasmussen, senior research associate and avian systematist at the Cornell Lab. “The entire tree of life for birds, built on the latest phylogenetic research, is now an interactive and downloadable dataset from Birds of the World that will stimulate endless questions and deeper research. The tree is a vital entry point for answering so many questions, such as how evolutionary history may have influenced beak shape, wing length, foraging habits, habitat preferences, or other traits in birds.”
“Birders will be excited by the Explorer's built-in personalization," says Marshall Iliff, eBird project lead who also serves on the Cornell Lab's taxonomy team with Dr. Rasmussen. By logging into the platform, birders can visualize the diversity of their eBird life list. Users can also zoom into different parts of the tree to examine their birding history in the context of bird orders, families, and genera, revealing evolutionary patterns in the species they've observed and highlighting gaps they might want to fill. Suddenly, a birder's life list becomes a personal journey through evolutionary history, showing not just what they've seen, but how those species fit into the grander story of avian evolution.
Users of this tool are bound to encounter a few surprises. For example, how can Downy Woodpeckers in North America look so much like Hairy Woodpeckers, and yet not be closely related? Why do falcons, despite being fierce hunters like hawks and eagles, actually belong on completely different branches of the family tree? Taxonomic puzzlers like these will give anyone seriously interested in birds a lifetime of wonder.
Try the Phylogeny Explorer for free from January 28 through February 1, 2026: Visit https://birdsoftheworld.org and click on ‘Phylogeny’ below the search bar. To subscribe to Birds of the World, click Subscribe and enter the coupon code TREEOFLIFE to save 25% off a subscription plan.
This project brings to life the research concepts developed by McTavish et al., in their 2025 PNAS publication. You can learn more about the methodology for developing the tool on the About page and Data Sources section.