There are more than 330 different hummingbird species flitting around the Western Hemisphere, but only 5 percent of them actually live in the United States or Canada. Most species prefer the tropical climate of Central and South America. However, certain hummingbirds do migrate north to breeding grounds in southern U.S. states (and certain western U.S. states), beginning as early as February. Their migration is thought to be triggered by changes in the amount of daylight and by the emergence of flowers, nectar, and insects. Instinct also plays a role in their decision to migrate.
Flying machines, fueled by nectar:
- Hummingbirds increase their body weight by as much as 40 percent before starting the annual migration. They fly alone, often following a predictable path, stopping along the way to refuel on nectar.
- During migration, a hummingbird's heart beats up to 1,260 times a minute and its wings flap between 15 and 80 times per second. It is thought that a hummingbird can travel as far as 23 miles (37 km) in a day.
- Flying 500 miles (805 km) across the Gulf of Mexico, these little birds must remain airborne for about 20 hours. Hummingbirds typically weigh less than 5 grams (0.176 oz) -- about the weight of a nickel.
