Celebrate our travelling feathered friends on World Migratory Bird Day! Some migrations are truly astounding. The bar-tailed godwit embarks on a 6,835-mile nonstop flight across the Pacific from Alaska to New Zealand. The tiny ruby-throated hummingbird, weighing less than a penny, and makes the trip all the way across the Gulf of Mexico—a seemingly impossible feat for its size. Migratory birds navigate the globe, instinctively knowing when and where to move to exploit seasonal abundance. The Arctic tern outshines them all with its intercontinental journey from pole to pole, covering more than 18,000 miles. Their migration routes are passages created based on environmental cues.