During their migration, whales continue swimming day and night. It is likely that the warmer waters of Mexico help newborns to conserve body heat. The whales may also prefer the lagoons because they are protected areas of calm, warm water, with very few sharks. These are the only natural predators of the gray whale. Orcas eat mothers and baby whales off the coast of Oregon.
Orcas sometimes hang onto the flukes of the gray whale to tire it out before the attack.