Every winter in Hawaiʻi we anticipate the return of three particularly industrious manu friends: ʻakekeke (ruddy turnstones), hunakai (sanderlings), and ʻūlili (wandering tattlers). Along Hawaiʻi’s sandy and intertidal shorelines, these small shorebirds hurry through estuaries and salty whitewash, probing, flipping stones, and chasing receding waves in a tireless search for food.
This mighty trifecta arrives only after completing one of the most astonishing feats in the animal kingdom – transpacific migration. Upon the close of the Arctic breeding season, they launch southward over thousands of miles of continent and ocean.
How do they know their way? Long-distance migrations require using the sun, stars, and polarized light as compasses on their journey. But current research also suggests birds can “smell” their way towards land, as well as “see” Earth’s magnetic field through a light-sensitive protein in their eyes’ retinas called cryptochrome-4.
In the presence of short-wave light, this protein reacts to magnetic forces at the molecular level creating a superimposed magnetic mind map in the visual system. It’s an elegant, yet still unfolding, explanation for how these navigators cross with such extraordinary precision to find sanctuary and rest every year in Hawaiʻi
, hunakai (sanderlings), and ʻūlili (wandering tattlers).){kind=link}