Moving Up in the World

Migrations don’t always stretch across long distances. Some migrations move up and down.

Dall sheep live in rugged land in North America. They move as the seasons change. Their migration goes up and down. It’s called a vertical migration.

In spring and summer, Dall sheep graze in high-mountain meadows and on open slopes. When winter comes, the sheep move down the mountain. How do they know the way? Scientists think that the path is passed on by parents to their young.

The oldest sheep usually begins the migration, leading the others. They climb about 1,200 meters (about 4,000 feet) down rocky cliffs. Most spend their entire lives in this narrow band, moving up  and down.