Migration is the regular , seasonal movement of animals from one place to another and back again. It is not the same as simply wandering off — a migration follows a route that the animals travel year after year . Animals migrate for three main reasons : to find food when it runs short , to escape harsh weather such as freezing winters , and to reach safe places to breed and raise their young .
Why bother with such an exhausting journey ? Imagine a swallow in Britain . In summer the skies are full of the insects it eats , but in winter those insects vanish and the swallow would starve . So instead of staying , it flies thousands of kilometres south to Africa where insects are plentiful , then returns the following spring . Migration lets animals enjoy the best of two different places at the best times of year .
📷 sanchezn · CC BY-SA 3.0✨ The Arctic tern makes the longest migration of any animal — flying about 70,000 km each year between the Arctic and Antarctica , from one summer to another.
🔗 Match each reason for migrating to an example.
Wildebeest chase fresh grass across the Serengeti Salmon return to calm rivers to lay eggs Birds flee the freezing northern winter Swallows follow insects from Europe to Africa
Wildebeest chase fresh grass across the Serengeti Salmon return to calm rivers to lay eggs Birds flee the freezing northern winter Swallows follow insects from Europe to Africa
To reach safe breeding grounds
? Wildebeest chase fresh grass across the Serengeti Salmon return to calm rivers to lay eggs Birds flee the freezing northern winter Swallows follow insects from Europe to Africa
Wildebeest chase fresh grass across the Serengeti Salmon return to calm rivers to lay eggs Birds flee the freezing northern winter Swallows follow insects from Europe to Africa
One of the great mysteries of migration is how animals find their way over such vast distances without maps or signposts . Scientists have discovered several incredible tools . Many birds navigate by the position of the Sun during the day and the pattern of the stars at night . Salmon can smell the unique chemical scent of the exact river where they hatched . Most amazing of all, monarch butterflies and some birds have a built-in compass that senses the Earth's invisible magnetic field .
📷 Herbythyme · CC BY-SA 4.0🔗 Match each animal to its migration fact.
Returns to the exact river where it was born Up to 1.5 million cross the Serengeti every year Travels between polar feeding and tropical breeding waters Flies up to 4,800 km from Canada to Mexico
Returns to the exact river where it was born Up to 1.5 million cross the Serengeti every year Travels between polar feeding and tropical breeding waters Flies up to 4,800 km from Canada to Mexico
Returns to the exact river where it was born Up to 1.5 million cross the Serengeti every year Travels between polar feeding and tropical breeding waters Flies up to 4,800 km from Canada to Mexico
Returns to the exact river where it was born Up to 1.5 million cross the Serengeti every year Travels between polar feeding and tropical breeding waters Flies up to 4,800 km from Canada to Mexico
💡 Not all migration happens over huge distances . Some mountain animals simply move up and down the slopes with the seasons — that counts as migration too.
Migration uses up an enormous amount of energy , so animals must prepare carefully . Many birds eat so much before they leave that they almost double their body weight , storing the extra as fat to burn as fuel on the way. Some tiny birds then fly non-stop for several days and nights across open ocean , never landing to rest . A few species , like swifts , can even sleep for short moments while still gliding through the air.
📷 Danijel Mihajlovic · CC BY-SA 4.0⚠️ Climate change is disrupting migration . Warmer temperatures shift the timing of flower blooms and insect hatches , so arriving birds sometimes find their food has already disappeared .
🧩 Put the steps of a migratory bird's year in order.
Flies south again as days shorten in autumn ? ⤒ ↑ ↓ ⤓
Nests and raises chicks in the north ? ⤒ ↑ ↓ ⤓
Flies north in spring to breed ? ⤒ ↑ ↓ ⤓
Overwinters in warm southern lands ? ⤒ ↑ ↓ ⤓
✍️ Fill in the migration words.
Animals migrate to find _____ and to escape harsh weather . Before a long flight , many birds store _____ as fuel , and monarch butterflies navigate using the Earth's _____ field .
food fat magnetic muscle
