Humans have always migrated to survive. When glaciers advanced, when rivers dried up, when cities fell, people moved. Their journeys were often painful, but necessary, whether across deserts, ...

Billions of birds are on the move or getting ready to depart for spring migration. Warblers, shorebirds, waterfowl, raptors ...

Tracking migrants is a challenging task that policymakers, researchers and humanitarian organizations have long struggled to achieve. The data they use is often outdated, incomplete and inconsistent ...