Summary: Each year, small migratory birds track favorable environmental conditions by moving thousands of kilometers across international borders. In a rapidly changing world, the precise timing of these movements may increase vulnerability to environmental change, raising key questions about how tightly events are linked across the annual cycle and how much flexibility birds have to adjust their schedules. Addressing this requires a full annual-cycle view – including a better understanding of largely overlooked but extended non-breeding season, which has long been treated as largely stationary. Using a global database of year-round tracks from >2,000 individuals across 83 species, we quantify temporal coupling among major annual-cycle stages and then focus on an increasingly recognized behavior: non-breeding movements, where individuals relocate between multiple non-breeding sites.