Are birds the only animals that migrate?

No, Birds are one of many animals that migrate, Whales will migrate to the warm waters of Mexico or to the cold waters of the Alaskan area. Some other animals that migrate are:

Elephants

Buffalo

Sharks

Butterflies

Caribou

Frogs

Fish

Eels

Reindeer

Sea Turtles

Wildebeest

Zebras