The blue whale is considered the largest living marine mammal in the world.
In fact the blue whale is one of the largest animals to ever inhibit the earth and is even larger than most dinosaurs.
When fully grown these large marine mammals can measure in at over 100 ft. long (70 – 90 ft. on average) and weigh more than 180 tons (100 – 150 tons on average)!
Despite this whales large size the primary diet of the blue whale consists almost exclusively of krill, which typically measures between 1 -2 centimeters long, however on rare occasions some species of krill can grow to be nearly 6 inches long.
Blue whale range and status
In regards to their habitat the blue whale species used to be very abundant in all of the major oceans of the world until the 17th – 20th centuries when many of them were killed off during the whaling era so that their blubber could be used to make raw materials and commercial products leaving the blue whale species severally diminished.
While these marine mammals can still be seen swimming in many of the worlds major oceans such as the Antarctic Ocean, Atlantic Ocean, Indian Ocean and the Pacific Ocean their numbers have dwindled significantly and their populations have become scarce and largely fragmented.
Before the whaling era it was estimated that 200,000 to 300,000 or more blue whales lived in the worlds major oceans.
A survey done in 2002 (post whaling era) estimated that there are around 5,000 to 12,000 blue whales currently in existence, but some scientists believe that these numbers may be underestimating the true population of blue whales currently in existence.
Today, these marine mammals are considered protected and are listed as an endangered species.
Any attempts to hunt them is considered illegal and those who are caught could face steep fines and/or jail time.
Migration behavior
Unlike humans the blue whale has two primary seasons known as feeding season and mating season.
During their feeding season (which typically occurs during the summer months) they can be seen stocking up on large quantities of food in preparation for their migration towards area’s such as the Farallon Islands, Channel Islands and Monterey Bay.
When mating season comes around (during the winter months) these majestic animals migrate towards the warmer tropical regions of the world near the equator to locations such as the Golf of Mexico and Costa Rica, where they can bare their offspring and/or mate with other whales.
These marine mammals tends to prefer living in deep temperate cold region waters, probably due to their significant layer of blubber, which keeps them well insulated and because the majority of their food also likes to inhibit cold waters.
Unfortunately at this point it is still unclear as to whether the blue whale species is recovering as much as we had hoped.
As stated earlier the blue whale species is currently listed under the endangered species status and is a protected species.
The importance of migration
Migration plays an extremely important role in the survival of the blue whale species.
It allows these marine mammals to feed in highly krill populated areas during their feeding season so that they can develop the thick layer of blubber they need to make their long migration trip.
During the winter it allows them to breed in warm, safe waters during mating season where they are at less of a risk of being attacked by potential predators.
The 10 – 12 months reproductive cycle of the blue whale makes it easy for these marine mammals to give birth in the same location they become pregnant in which is important as their young is best suited to be born in warm, temperate waters.
This also allows the children to feed on their mothers milk and build up their strength before heading back to their feeding grounds which can be thousands of miles away.