Many people know it’s fall when birds head south, but migration is far more than just an autumn journey. Do you know these crazy migration facts?
Migration Happens Year-Round
It may seem that spring and fall are migration seasons, but there are birds somewhere migrating 365 days a year. Birds with longer journeys may begin earlier, and some birds are slower migrants that may take several months to complete a one-way trip. Spring and fall are peak migration seasons when greater numbers of birds and more diverse species are actively on the move.
Birds Can Fly Higher Than Planes
While most birds migrate under 2,000 feet of altitude, some species go much higher. The bar-headed goose can migrate at altitudes over 29,000 feet as it flies directly over the Himalayan Mountains along its migration route, whereas smaller commercial planes (those with propellers) cannot generally fly higher than 20,000 feet, and short-duration flights may be even lower.
Some Birds Fly As Far As to the Moon and Back
Birds complete their round-trip migrations every year, and depending on how long they live, they can fly hundreds of thousands of miles. The Arctic tern, for example, breeds in the northern polar region but spends its non-breeding season near Antarctica, a 22,000-mile round trip. These birds can live more than 30 years, adding up migration mileage greater than flying to the moon and back.
Fat Birds Fly Further
Birds bulk up before migration, spending anywhere from just a few days to a month or more adding body fat. The hormonal drive to gain weight in preparation for migration is called hyperphagia, and birds may as much as double their weight before they take flight on their journeys. This is why it is vital to provide birds with high-calorie foods in fall, such as sunflower seeds and suet.
Daytime Birds Are Nighttime Migrants
Many songbirds, such as thrushes, warblers, buntings and tanagers may not be active at night during the summer, but during migration time they are superb nighttime fliers. Migrating at night helps birds avoid many predators and take advantage of cooler air for easier flight. Both the moon and the stars are navigational aids, and birders can enjoy nighttime migration by listening for birds that call in flight or watching the surface of a full moon for birds to pass by.
Want to learn more about bird migration? Check out more migration trivia!