Animal Migration

Look up in autumn and you may see long lines of geese honking across the sky. Canada geese fly south before winter comes. They head for warmer lakes and fields where water stays open and food is easy to find. In spring they fly north again to nest and raise chicks.

Geese often fly in a V shape. Each bird saves energy by riding the air pushed aside by the one ahead. When the leader gets tired, another goose takes its place. Flying together makes the long trip possible.

Pacific salmon make one of the bravest trips on Earth. They hatch in rivers, swim out to the ocean to grow big, then return to the very same river to lay their eggs. They push up rapids and leap over falls to get home. Nothing stops them for long.

Salmon do not just feed themselves. Bears, eagles, and even forest trees depend on them. When salmon die after spawning, their bodies feed the woods. Migration moves food from the sea into the land.

Long ago, giant wild cattle crossed a land bridge from Asia into North America. Their young became the bison we know today. Huge herds once roamed the plains, always on the move. They followed fresh grass as the seasons changed, seeking green fields spring after spring.

Moving kept the herds fed and healthy. New grass grew back where they had grazed. Wolves followed the herds too. Migration shaped the whole plains, from grass to bison to wolf.