1. Migration comes from the latin "migratus" which means to change. The birds change their geographic location with the seasons.
2. While Spring and Fall are peak migratory periods, some type of bird is migrating 365 days a year.
3. Birds experience "hyperphagia"as they prepare to migrate. Their body stores fat, sometimes doubling in weight, to use as energy for their long flight.
4. Migration lasts anywhere from a few weeks to four months, depending on the bird, the distance it flies, its speed, its routes and its number of stopovers.
5. Hawks, swifts, swallows, and waterfowl migrate during the day while songbirds migrate at night so as not to be seen by their predators.
6. Birds navigate by the stars, the sun, the wind patterns and landforms. During their migration, the following threats may arise: window collisions, confusing lights, hunting, habitat loss and predators.
7. Birds fly 15 to 600 miles per day during their migratory period.
8. Birds that must cross an ocean, called "transoceanic migrants", sometimes fly for 100 hours at a stretch.
9. Birds travel at speeds of 15 to 50 miles per hour depedning on the species, the flight pattern and the prevailing winds.
10. Birds fly at about 2000 feet altitude; however, some birds have been recorded at 29,000 feet (for instance, birds that must rise above mountain ranges).
Photo courtesy http://songbirdgarden.com.