Every year, billions of birds undertake extraordinary migrations, crossing vast deserts and open seas with no place to stop, feed, or rest. A new international study published in iScience by a consortium of researchers from Tour du Valat, CEFE/CNRS, Muséum national d’Histoire naturelle and Swiss Ornithological Institute reveals that small migratory birds adjust how high they fly over these ecological barriers, and that their strategies depend on wing morphology and plumage color.