Radar-measured passerine vertical speeds reveal a migratory switch near a major barrier

Successful accomplishment of long-distance migration necessitates optimal decision-making processes. Throughout their migration, birds need to constantly choose to fly or to stop. Passerine migrants integrate internal (e.g., lipid deposition) and external (e.g., prevailing winds) factors resulting in specific departure or landing times. We calculated individual departure and landing timing using v…