Traveling as much as 14,000 miles per year, the gray whale is known to make one of the longest migration trips of any known mammal. Each year around October, the gray whales in and around the eastern pacific Alaskan waters begin their migration trip from their feeding grounds to their mating grounds around the Baja peninsula of Mexico and the southern Gulf of California.
As the Alaskan waters begin to freeze over and their food supply migrates to warmer climates, these large marine animals also begin their trip to warmer tropical climates. During this migration trip, the gray whale travels at an average speed of around 5 mph for two to three months until it reaches its destination.
Pregnant females are often the first whales to arrive at the mating grounds. They need to find protection for their soon-to-be newborn children from potential predators such as killer whales and sharks, which may be interested in hunting their defenseless children. Non-pregnant but fertile females may also be found arriving early to look for an eager mating partner.
By mid-February to March, most of the population can be seen mating, socializing, and giving birth at the mating grounds. Throughout March, gray whales that have finished mating may begin traveling back towards their feeding grounds in the eastern pacific with pregnant mothers and females that have just given birth staying behind until mid-April to May before leaving.
This is likely to ensure that they have enough time to recover from the mating season and make sure their young will be able to safely make the long trip back to their feeding grounds around the Alaskan waters.
Aside from the seasonally migrating gray whales, a small population spends its year traveling between Canada and California rather than making the long 7,000-mile journey towards the Alaskan waters from the Gulf of California and the Baja peninsula of Mexico.
Is migration important for gray whales?
Migration is significant for the gray whale. Migration allows these marine mammals to move to places where they can find abundant food sources. It also allows them to gather together to meet up and mate with one another or reproduce their offspring in a safe and warm environment that is important for their newborn children.
Lastly, migration may be considered a form of social gathering as some pods may travel together and protect one another as they head to the same destination.
What happens if the gray whale doesn’t migrate?
If a gray whale did does not migrate, it may end up isolating itself from other gray whales that travel and migrate together, causing the whale to be very lonely and isolated for several months. It may also make it difficult for the whale to find a sufficient food source or mating partner if the gray whale decided not to migrate.
Even if an entire group decided to stay in their feeding grounds all year long, they might lower their newborn’s survival rate as the child may have a more difficult time dealing with the cold and other threats that may be around them in the colder waters.
On the other end, if these marine mammals chose to stay in their mating grounds all year long, they may find it more difficult to find sufficient sources of the food they are used to eating in their feeding grounds.
Do other whales migrate?
Yes, several other whales are known to migrate. In fact, there are several different patterns these marine mammals are known to use depending on their species. While some whales may choose to migrate between seasons, other species can inhibit the same environment throughout the year.
Some species do not follow a standard migration pattern and may scatter or travel to different parts of the world but gather back together during mating season. Species such as killer whales (killer whales are dolphins) are known to migrate to maintain their food supply, so they may choose to migrate with their food rather than traveling for mating purposes.
Anything else we should know about migration?
Depending on the whale’s species, the length of migration can vary significantly from traveling away from the shoreline and into offshore waters within the same local area to avoid the ice to making extremely long-distance trips from the arctic to the tropical regions of the world and back. Fasting can also vary among different whale species from several days to several months.
Some species may fast to lose some of their thick blubber, making it easier for them to withstand warmer climates.
In addition to fasting to lose blubber and maintain their pace, there is also the fact that different whales consume different foods, so the availability of specific food sources can change drastically from one species to the next, making it easier for some whales to find food during their migration than others. If you would like to learn more about whale migration, be sure to check out this article: Whale Habitat and Migration Patterns.
Additional Information about The Gray Whale
As a species, the gray whale is part of the cetacean family, which comprises over 80 different species of marine mammals. Regarding the gray whale, these marine mammals are known to grow to lengths of up to 50 long when fully matured and can weigh as much as 40 tons. Despite its large size, the gray whale survives on a diet that consists primarily of small benthic crustaceans.
When it comes to giving birth, the average gestation period (from conception to birth) for a female gray whale lasts around 13.5 months long. Newborns are fed milk for the first 6 – 8 months of their life or until they can hunt for food on their own.
The average lifespan of a healthy gray whale is 50 – 70 years. Although these marine mammals can grow to be quite large, younger and less experienced whales may fall prey to hungry sharks and killer whales.