There are over 80 species of whales observed by researchers. Humpbacks and Gray whales are often mentioned in news stories. Not all species of whales migrate. Young calves that are not yet ready to breed, tend to stay closer to normal feeding grounds. Migratory habits of species, population and individuals could differ due to variety of reasons.
Two main reasons often mentioned for migration is temperature change and breeding. Cold temperature provides ample opportunities for finding easy feeding grounds. On the other hand warm water, 40-60 degrees Fahrenheit, is sought for mating, breeding and to give birth. There are other factors such as depth of water, salinity and reduced risk of young calves to predators that may affect the migration.
Humpbacks whales are found throughout all oceans of the world. In the Pacific Ocean, compared to Gray whales, they travel less from northern Arctic cold waters to tropical waters. Gray whales have been documented to travel the longest distance from Alaska to California and Mexico. This trip could be between 8,000 to 11,000 miles and take two to three months. Southern right whales that are similar to Humpbacks travel from Australia to Antarctic feeding grounds during summer to feed.
