The stars appear to rotate in the sky, raising the question of how birds can use stars to navigate during migration. Ornithologist Stephen Emlen brought Indigo Buntings to a planetarium, tracking their movements as the simulated night sky changed above them. The buntings oriented themselves using star patterns that appear to rotate the least — especially the North Star, Ursa Major and Cassiopeia.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.