WHALES – MIGRATION
Migration is defined as the movement (of humans or animals) from one fixed location to another. There are a number of whale species that migrate. This is done for different reasons; namely 1) to mate, 2) to feed, 3) to maintain an optimal level of food availability, and 4) simply for the sake of travelling and moving around. There are, of course, a number of whale species that do not migrate at all, but remain in the waters in which they are safest and most comfortable.
Significant species that are known for their regular migrations include Killer Whales, Humpback Whales and Sperm Whales.
Humpback Whales make a long migration. In fact, it is renowned for being one of the longest migrations in the animal kingdom (along with the Gray Whale). Every year, the Humpback Whale will travel thousands of miles towards the warmer waters of the equatorial region to mate and give birth. During the winter and their migrations, these whales can survive from the energy reserves stored in the hefty layer of blubber that it built up during easier times. Interestingly, Humpback Whales will migrate for mating purposes, even when their current location has a rich supply of food.
Killer Whales do not travel for mating purposes or to find warm water. Rather, they simply follow the food. Therefore, where the fish and other prey are, the Killer Whales that feed on them can be found. Still, Killer Whales can be found in almost all the oceans of the world, being resilient to different water conditions and able to adapt to their environment.
Sperm Whales do not have a specific route along which they migrate. Rather, they simply wander the world’s oceans throughout the course of their lives. However, mating season will usually see them moving towards the warmer waters of the equator. Beluga Whales are known to make seasonal migrations from their usual Arctic homes. However, they do not usually travel very far.
Blue Whales, on the other hand, stick to the cold waters in the feeding season, when they need to build their blubber and energy supplies. When they need to mate, they travel to the warm waters of the tropics.
Narwhals are usually found in the chilly waters just off the Greenland and Canadian Arctic coasts. However, come winter, they move into deeper waters to avoid the ice that forms on the surface of the shallow waters.
Whether or not a whale migrates is not only dependent on its specific species. Young whales that are not mature enough to reproduce have no need to move to seasonal mating grounds, for example. These ones will stay in their usual habitat and take advantage of the rich food supplies while their older counterparts make the long journey.
In order to make a migration, it is essential that the whales have built up a layer of blubber that is thick enough to provide it with the energy it needs for the long journey. This means months of dedicated feeding, which requires some species to hunt actively.
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