Each year, the bar-tailed godwit embarks on a migration that defies imagination. Leaving Alaska at the end of summer, it heads for New Zealand in a single, continuous flight lasting about 8 to 10 days. That’s over 7,000 miles across open ocean, without stopping to rest or refuel.

What makes the journey even more remarkable is that young godwits do it without guidance from adults. After hatching in Alaska and feeding to build up fat reserves, they set off entirely on their own. 

Scientists believe they navigate using a combination of the Sun’s position, the stars, prevailing winds, and Earth’s magnetic field, which acts as an internal compass so precise it can guide them across the Pacific to a destination they have never seen.

The godwit’s endurance comes from physiology finely tuned for the task. Before migration, it nearly doubles its body weight in fat, then burns that stored energy with incredible efficiency. Even its internal organs shrink to lighten the load, making room for more fuel. By the time it lands in New Zealand, the bird has lost up to half its body weight — a living testament to the extremes of migration.