Blue whales, balsenoptera musculus, are the largest animals on Earth. They measure 65 to 105 feet (20 to 32 meters) and weigh anywhere from 100 to 200 tons (90,718 to 181,437 kilograms) with females being larger than males. Their heads make up around 25 percent of their entire body length. Like all whales, blue whales are mammals and therefore, have to come to the surface in order to breathe. They also have some hair or fur along their bodies. On the surface, they are a mottled blue-grey color with a yellowish hew on their underbellies due to the millions of microorganisms that will take up residence on their skin. Under the water however, blue whales do look truly blue.
Blue whales can be found in oceans all over the world. They tend to be solitary animals, traveling and feeding all alone at depths of up to 1640 feet (499 meters). A pair of blue whales traveling together is not uncommon, although it is unknown how long such partnerships last. Sometimes they will gather in groups of anywhere from 50 to 60 individuals when a good feeding ground is found. Despite the many blue whales that may gather, they will usually not interact with one another and instead leave each other alone to feed.
Despite their enormous size, the diet of blue whales mostly consists of krill. They have been known to eat the occasional fish, plankton or squid as well. They can eat as much as 4 tons (3,628 kilograms) of food in a day, feeding at depths of around 330 feet (100 meters). Blue whales catch their food by first consuming a large amount of water (along with anything in it) and holding it inside their mouths. They will then release the water out of their mouths while keeping all the food through the use of baleen plates which keep the food from leaving with the water. After they are done filtering, they will proceed to swallow their food. Blue whales have few natural predators, with sharks and killer whales being a couple of the few creatures that will attempt to try and feed on these gentle giants. If alarmed, blue whales can swim at speeds of up to 30 miles (48 kilometers) per hour, although they will usually cruise at anywhere from 5 to 12 miles (8 to 19 kilometer) an hour when calm.
Blue whales usually give birth every 2 to 3 years at the beginning of winter. After a gestation period of around 1 year, females will give birth to a single offspring. The babies will feed on their mother’s milk and gain around 200 pounds (90 kilograms) every day for their first year. If the young blue whales can survive, they can grow up to be 80 to 90 years old on average, although there have been finds of blue whales being as old as 110.
Blue whales are an endangered species. They were almost hunted to extinction between 1900 to the mid-1960s. They were given protection in 1966, but recovery has been slow. Hopefully, blue whales will be able rebound and never have to worry about extinction ever again. After all, such a majestic and gentle giant deserves to live and prosper for future generations to see.
