Blue Whale

Classification

The blue whale is a type of baleen whale that, depending on the time of year, is found in oceans all across the globe. Its scientific name is Balaenoptera musculus. Balaenoptera translates to “winged whale”, while musculus translates to “muscle” (although it could actually be “mouse”, which would have been a bit of a joke from the person who originally named the blue whale.

Anatomy and Appearance

This great mammoth has an extremely long, narrow body which means that allows them to swim more easily. Without a doubt, this species of whale is the biggest whale living today. Their skin is smooth and greyish-blue in color with a lighter underside. They have a series of pleats on their throats which allows them to expand to more than four times their normal size feeding. The tail of the blue whale splits into rubbery flukes which help to improve swim speed and efficiency.

Like other baleen whales, blue whales have almost 400 baleen plates instead of teeth. These are hard and bristly to function as filters for blue whales to feed by taking in great amounts of water.

Blue whales have two blowholes that expel water from their lungs. They do this from the top of their heads when they come to the surface every so often to breathe.

4 Types of Blue Whales

There are four recognized subspecies of the Blue Whale and potentially a fifth subspecies off the coast of Chile.

• North Atlantic & North Pacific Blue Whale – North Atlantic & North Pacific Blue Whales can be found in a few regions including New England to Greenland, the U.S. West coast, and from Alaska to Hawaii to the Kamchatka Penisula.
• Southern Ocean (Antarctic) Blue Whale – Southern Ocean (Antarctic) Blue Whales are found all around Antarctica, but they do venture pretty far north searching for food through several different oceans.
• Indian Ocean & South Pacific (Pygmy) Blue Whale – Indian Ocean & South Pacific (Pygmy) Blue Whales despite their name, still reach an average length of 78 feet.
• Northern Indian Ocean Blue Whale – Northern Indian Ocean Blue Whales are almost always found in the Northern Indian Ocean with little variation.

Evolution and History

Blue whales are found throughout the world’s oceans, except for the Arctic. Growing to around 100 feet long, it is thought that it could be the biggest creature that has ever existed. It is definitely the largest alive today. Learn about the largest ocean animals to have ever lived here.

The blue whale diverged from other Balaenopteridae (including fin whales and northern minke whales) between 5 and 10 million years ago, and the oldest fossil representing something similar to today’s blue whale dates back almost 2 million years ago.

Although their enormous size and slow-maturing nature have meant that the world’s Blue Whale population has never been greatly numerous, they have drastically declined in numbers due to having been hunted by humans, particularly over the past one hundred years.

Blue Whales are now legally protected from commercial whaling.

Distribution and Habitat

Found in oceans mostly worldwide, blue whales migrate at different times of the year. In the summer months, Blue Whales are found in the cold waters where they feed on plentiful food, before moving towards warmer waters to breed. The migratory patterns of blue whales are generally less well understood and seem more unpredictable than other baleen whales, even skipping migration some years.

Behavior and Lifestyle

Unlike some other whales, blue whales are primarily solitary animals. They do sometimes gather to feed in groups and when they are breeding or mothers are with young.

Blue whales are known for their use of a variety of sounds (known as songs) including hums, squeaks, and rumble to communicate with one another, particularly during the breeding season in winter. Maybe not too surprisingly, these gigantic mammals make some enormous noises! In fact, reaching volumes of over 180 decibels they make the loudest sound of any other animal.

The Blue Whale has very small fins and flippers so rely on its enormous tail to help it to plow through the ocean. Blue Whales also use their tails to make deep dives as by bringing it above the surface of the water, they are able to get enough power to travel up to 200 meters steeply down into the sea.

Reproduction and Life Cycles

Blue Whales breed in the warmer, tropical waters during the winter or early spring when after a gestation period that lasts for nearly a year, the female Blue Whale gives birth to a single calf on her return to the region the following year. After spending all summer feeding in the cold, rich waters at the poles, female Blue Whales eat almost nothing whilst they are nursing their young. Newborn Blue Whales already measure seven meters in length and weigh around 2.5 tonnes and remain by their mother’s side for at least their first year. Before they are weaned by the time they are eight months old, Blue Whale calves are known to consume up to 90kg of milk every day. Blue Whales are able to start reproducing themselves when they are between 10 and 15 years old with females giving birth every two or three years. Blue whales can live for up to 40 years.

Diet and Prey

The Blue Whale is a carnivorous animal that despite the fact that it doesn’t have proper teeth, survives on a diet that is mainly comprised of krill and small crustaceans, along with the occasional small fish. Blue Whales feed by swimming up towards a shoal of prey and thanks to the pleats on their neck which allows their throat to expand, take an enormous gulp of water into the sac created in their lower jaw and shut their mouths. The water is then expelled but thousands of tiny creatures are retained by their fine baleen plates which are then swallowed. Blue Whales are able to consume up to six tonnes of prey every day during the summer months which they spend in the cold, rich waters around the poles. Although Blue Whales are known to eat a tremendous amount during the summer, when they migrate to the warmer waters for winter to breed they will barely eat anything at all. For a complete analysis of their diet, give our ‘What Do Blue Whales Eat?’ page a read!”

Predators and Threats

It’s probably no surprise that blue whales have no predators in the ocean, because what could eat them? They sit at the very top of the size category for animals. Their young, however, are at risk from attacks by killer whales which are able to hunt them down with cunning and intelligence.

Sadly, once whalers and hunting technology produced more advanced harpoons in the 19th century, mankind increased commercial hunting of the huge beasts. Throughout the first half of the 20th century, the blue whale population was crushed due to overhunting for their valuable blubber and meat. Since the 1960’s there has been a global ban on commercial whaling on the blue whale.

Blue Whale Interesting Facts and Features

Here are some great blue whale facts!

• The largest blue whale ever recorded was captured in 1947 and weighed 418,878 pounds.
• Blue Whales must come to the surface to breathe in air, which happens every 8-12 minutes.
• 9 meters is how high blue whales can push water, air, and mucus out of their blowholes.
• The brain of a Blue Whale weighs as much as 15 lbs.
• The lungs are so large that one full breath from a blue whale could fill 2,000 ballons.
• The heart of the Blue Whale is so big that it is around the same size as a small car.
• The arteries of the heart are wide enough for someone to swim through.

Conservation and Human Relationship

The blue whale’s relationship with humans has changed drastically over the past 80 or so years. Before the 1960s, blue whales were commercially hunted into scarcity for products refined from their meat and blubber. In fact, 1978 was the last year that a blue whale was intentionally hunted.

Many years ago, man would only be able to obtain blue whale meat and blubber when there was a beaching or some other event that washed one ashore. As whaling technology improved, hunters were able to really pursue blue whales in the open oceans.

Because of the overhunting, the blue whale population has dropped from what biologists estimate 200,000 in the 1800s to 20,000 today. They are listed by the IUCN as an animal that is Endangered. Their greatest threat today is global warming.

Now, blue whales are part of sightseeing tours and are highly protected. These huge, unique whales are coveted today for the wonders they are.