Animals on the Move
Each spring, many animals migrate thousands of miles to get to places with good food and weather
This map shows the bar-tailed godwit's migratory route. These birds fly 6,800 miles from Alaska to New Zealand, and back! (Jim McMahon)
The seasons are changing, and that means animals all over the Earth are getting ready to migrate.
Migration is the movement of animals from one place to another. Many animal species migrate when the weather changes around this time of year. When the weather changes again, they migrate back to where they started.
Most migrate to find food or a better place to have babies. When it starts to get cold in autumn, for example, the bar-tailed godwit flies south from Alaska to New Zealand, where it’s warmer and more food is available. Then it travels back north during the spring and summer months, when it’s warmer there. That’s more than 6,800 miles of flying each way—the longest nonstop migration of any animal!
“Birds and many other types of animals have a built-in compass,” says Mary Deinlein, a bird expert at the National Zoological Park in Washington, D.C.
Animals have different methods to find their way from one place to another. Some have great memories and use landmarks, such as the stars, sun, mountain ranges, and coastlines, to remember the right path.
Pigeons, for example, use their sense of smell to remember which landmarks to pass on their migratory route.
Other kinds of birds can sense the Earth’s magnetic field—where energy is pulled like a magnet to the planet’s axes at the North and South poles. Scientists believe this works like a map for many migrating animals.
GOING THE DISTANCE
Salmon, like many species, migrate thousands of miles. Every year, the fish swims from the ocean back to the same river where it was born to lay its own eggs. The salmon’s young will then repeat the cycle. They will migrate to the ocean, then return to the same river the following year.
Migratory animals often use the same route every year. Some animal species have traveled the same path for thousands of years.
Humpback whales migrate farther than any mammal in the world. They swim about 5,100 miles to Central America’s warmer waters in the fall to have babies. Then the whales return to Antarctica’s colder waters in the summer, where there is more food for them.
Bison, rattlesnakes, and butterflies migrate when the seasons change. Even mountain goats migrate. They travel vertically or up and down, along their mountain homes. They move down the mountain during colder weather to find food and head back up to avoid predators as the weather warms.
So when you see your first robin this spring, remember to welcome it home. It’s probably tired after its long journey!