Why do whales migrate between cold Pacific feeding grounds and warm breeding grounds?

Whales migrate between cold and warm waters to optimize their survival and reproductive success, balancing the need for abundant food with the requirements of calving.

• Feeding Grounds: During the summer, whales frequent high-latitude, cold-water regions, such as the northern Pacific Ocean. These areas are characterized by increased biological productivity and nutrient-rich upwellings, which provide the massive food supplies necessary for whales to build up energy reserves.12
• Breeding Grounds: In the fall, whales move toward warmer, lower-latitude waters near the Equator to breed and give birth. These warmer environments are generally more suitable for calving, as they provide a less thermally demanding environment for newborns that have not yet developed the thick layers of blubber required to insulate against extreme cold.132

This seasonal cycle allows whales to exploit the high productivity of polar regions while ensuring their offspring are born in more temperate, protected conditions.12