Our guest post this week is by Emily Murgia, Education Programs Specialist with the Friends of the National Zoo.
For centuries of travel, man has looked to the skies for guidance and direction. But we’re not the only ones. Studies show that birds, too, use stars to find their way.
Bird migration is the seasonal movement of birds. Birds migrate to find food or to breed, and may travel long distances to do so. But whether the trip is long or short, it is not so much the destination but the journey. How exactly do birds know how to get from point A to point B?
Migratory birds use a variety of cues to know where to go. For example, some use prevailing wind patterns. Wind patterns are seasonal, so birds can travel with the wind to reach their destination. Some birds use landmarks in the form of topographic features (i.e. coastlines, rivers, mountain ranges) to navigate. Others may use the small grains of a mineral called magnetite that can be found just above their nostrils. Like a compass, these minerals react to the Earth’s magnetic field and can tell the bird which direction is true north. Day fliers, on the other hand, use the sun and its position in the sky to tell direction, utilizing the setting sun to identify west.
Then there are the night fliers. Along with a combination of the methods described above, these birds also use the stars to navigate.
The indigo bunting, a small songbird of North America’s east coast, is one such star gazer. Having studied the indigo bunting, scientists have determined that birds start to learn the star patterns around the North Star starting at a very young age. Having memorized the constellations that surround this reliable due north icon, birds can migrate at night.
Birds learn the constellations at a young age; those birds that are unable to observe the stars early on are then unable to migrate successfully. Not seeing the stars is becoming a problem late in a bird’s life, as well. As cities grow, so does their light emittance. Light pollution is clouding the skies and is creating dangerous mazes of reflective glass buildings for the birds to navigate.
Birds all over the world are experiencing difficulties migrating. Along with light pollution, habitat destruction is affecting the birds’ ability to travel, limiting feeding and resting space, as well as homes. The Smithsonian’s Migratory Bird Center is doing its part to “foster greater understanding, appreciation, and protection” for migrating birds.
The National Zoo is home to many African birds. Come visit us in DC to see hornbills, pygmy falcons, cranes, and more! Help us build our African animals a new home and get some new neighbors! Learn more by visiting with our African Animal Ambassadors on weekends in May or visiting our website to find out how you can help.