For a variety of reasons, such as food and climate, some animal species migrate on a regular basis.
True migration is the two-way seasonal journey animals make from one area to another. For some species of migrating animals, to stay put would be a death sentence. For many animals, these migrations are spectacular in extent, range or behavior.
It is still not completely understood how some of these animals are able to sustain and navigate their way on long and/or dangerous migrations. The following are just a few examples of the many animal migrations that take place each year around the world.
The ruby-throated hummingbird is the smallest of all birds. This tiny 3.5-inch bird flies by beating its wings 60 to 80 times a second. Each autumn, many of these birds fly non-stop more than 500 miles from North America across the Gulf of Mexico to spend the winter in South America and then return in the spring. It is amazing that this tiny bird can store enough energy to fly continuously for the 18 to 22 hours required to fly each way in order to complete this migration.
Each autumn, millions of fragile monarch butterflies, born in the warm summers of Canada and North America, fly some 2,000 miles to overwinter in Florida and Mexico and back again in the spring. These delicate creatures will travel some 80 miles each day.
Swallows and martins, breeding in the European spring, must be back in North Africa before the winter frosts kill both them and the insects they feed on.
Many whales feed in the polar seas that are plentiful with food, while later swimming to the warmer waters of the tropics to breed. The common eel migrates from the tropical seas to European rivers as a larva, and then returns many years later as an adult to breed again.
The white stork that nests in Central and Eastern Europe journeys some 8,000 miles in flocks of thousands to overwinter in Africa and Iberia. They use two, very different out of the way routes, in order to avoid flying over the Mediterranean Sea. Each year Arctic terns make a round-trip journey of some 22,000 miles over the featureless ocean traveling from the Arctic to the Antarctic.
Here in the Midwest, we watch the ducks and geese migrate each spring and fall. Animals are amazing.
Larrie Stone is a retired Dana College science professor.