The Blue Whale – Virgo

The Blue Whale

General facts about Whales.

Whales are dynamic, large, and impressive creatures, roaming all of the world’s oceans. They’re classified as Cetaceans, which houses Dolphins and Porpoises as well. These friends are also distantly related to the Hippopotamus, with a shared ancestor of Anthracotheres, which went extinct 2.5 million years ago. The Anthracothere was a water-loving land-mammal, which evolved into 126 different species! Early Whale fossils have been found with long legs, which then shrunk and became long necks before the version of Whale we see today. Today there are 89 species of ocean-bound Cetaceans from their prehistoric ancestor.

Although Whales are undoubtedly majestic, they have been hunted by humans for centuries. It is estimated that mankind has killed 3 million Whales in the last century alone. Today, there are only an estimated 1.7 million Whales left in the oceans. Even after decades of protection, 13 great Whale species are classified as endangered. In this article we are focusing on the largest of all, with a history as long as its tail: The Blue Whale.


When we talk about Blue Whales, one key identifier sets our friends apart from any other mammal: their monumental size. The Blue Whale is indeed the largest mammal to have ever existed. With all that power, these beauties can dive deeper than any other sea creature.

They also have one of the largest appetites in the ocean! Their large intake of small fish makes them a vital part of the ocean environment, and this symbiotic relationship has existed for over 55 million years.

The Blue Whale, also called Balaenoptera musculus, is a Baleen Whale. This species of Whale relies on Keratin bristles instead of teeth to filter food. Within this family there are 4 species: Right Whales. Rorquals. Pygmy Right Whale. Gray Whales.

The Blue Whale is part of the Rorqual family, which also includes the Humpback Whale, The Minke Whale, Bryde’s Whale, and the Sei Whale.

The Blue Whale: Out of the Blue!

The Blue Whale
Photo by Chelsea Bradley on

What is the size, weight & colour of the Blue Whale?

The Blue Whale is by far the largest mammal on the planet. One Blue Whale can weigh as many as 30 Elephants! Depending on the size of our friends, they can weigh more than 200,000kgs. The females are typically longer, with the largest being 33.5m – much less than the heavier-boned males at 136,077kgs. A male Blue Whale grows to 21m-30m long and weighs an average of 181,437kgs.

Their colour is a spotted blueish- grey outside of water, but blends into its environment to create a beautiful deep navy blue underwater. Their underbellies are a breeding ground for yellow Algae, which covers the light grey skin they naturally have. Our friends have been perfectly designed to blend into their environments!

What type of vision does the Blue Whale have, and what sounds do they make?

The Blue Whale has poor vision, because this is something it rarely relies on. This is due to their sensitivity to scattered light, making darker, deeper water much more comfortable. They also have a poor sense of smell and must rely on other senses to find food.

The single most important sense for a Whale is sound and hearing. Their calls can travel 1500km to the ears of other Whales! Human-made sounds are created through air and cannot be heard effectively underwater. Blue Whales differ by producing deep sounds through their larynx, and echolocation signals through air sacs near their blowhole. These sounds translate to human ears as whistles and clicks but are louder than a jet engine at 230 decibels!

Are there any special or unique physical attributes?

The Blue Whales massive size and streamlined shape gives it a submarine-like appearance. Their head is flat and U shaped, which has a centre crease that trails from its upper lip to its blowhole. The 2 blowholes (each 50 centimetres in diameter) emit pressurized vapour when our friend surfaces! This water vapour can reach heights of 10 meters.

The Blue Whale relies on its large tail (fluke) to propel its massive body into the furthest depths of the ocean. It has 2 small flippers on each side to stabilize its large head, which takes up 25% of its body length!

On the underbelly of our friends, there are 80 expanding pleats of skin that provide space for food and water. These allow them to take in a lot of food during feeding and maintain hydrodynamics when swimming.

The Blue Whale

How fast is the Blue Whale?

The cruising speed of our friend is about 20km/h, with maximum speeds of 50km/h. In the span of a day, they can travel over 450km.

What are their Migration Routes?

In order for the Blue Whale to maintain its thick blubber, it must travel long distances for feeding grounds. Whales are able to fast for several months at a time living off of stored fat they accumulated in the feeding season. This season normally happens in the spring, near the North and South Poles where there is an abundance of Krill (a form of Zooplankton. Several subspecies of Blue Whales occupy different parts of the ocean, which determines their feeding ground.

Once the feeding season is over, the Blue Whale will return to more temperate waters in early winter. These waters house their breeding grounds, although scientists are unsure exactly where mating occurs. Female Whales will give birth in the warmest waters possible (depending on the ocean they inhabit).

The Blue Whale migration

How do they hunt, and what do they eat?

This Whale is a filter feeder, where it relies on Baleen Plates to strain fish. These plates are made from Keratin, and much like fingernails, are always growing. There are 300+ plates on each side of the upper jaw and none on the bottom.

Our friends feed by intaking large quantities of water with “lunging gulps”. This action is the largest biomechanical event on earth! This begins with the Whale assessing the quantity of prey, and once there is enough it makes a deep dive to maintain an element of surprise. The Blue Whale can trap up to 500kgs of food at one time. Once the food is trapped, the Whale strains water through its Baleen and expels it through the Blowhole, keeping all of its food trapped behind. This results in 3,600kgs of food being consumed in one day!

Photo by Harrison Haines on

What are their natural enemies?

Because of their sheer size, the Blue Whale has almost no predators in the ocean. The only exception is packs of Killer Whales (Orcas) attacking young or weak Whales in large groups.

If our friends are under threat, they will release faecal matter into the water and swirl it around themselves to deter predators. This is an effective method of deterring any hungry predator’s appetite.

Where do they live?

The Blue Whale can be found in oceans all over the world! They spend a lot of time 30m below the surface but can also be found 500m. They do not stay here long, as they can only hold their breath for 50 minutes and must resurface throughout the day for air.

Our friends usually live alone but can be found in groups as large as 60 in certain feeding grounds, such as the Farallon Islands. They do not form close-knit groups like Humpback Whales, which explains their more widespread population.

All about Reproduction.

Blue Whales reach sexual maturity between 5 and 10 years, and always migrate close to the equator to reproduce. Birthing occurs in early spring, with the calf immediately swimming to the surface for its first gulp of air. The Female Blue Whale has a gestation period of 11-12 months, birthing a calf every 2-3 years. These calves are born 8 meters long and can weigh 2,700kgs! To reach their impressive adult size, they must drink 500L of milk, gaining 90kgs a day!

The Blue Whale
Photo by Elianne Dipp on

What is their lifespan?

In the wild, the Blue Whale can live an average of 80-90 years. The oldest Blue Whale ever recorded was 110 years old. Quite a comparable lifespan to humans!


Whales surprisingly had a large role in ancient Egyptian mythology. Pharaohs were often referred to as “The Great Whale” comparing them to the large, god-like skeletons they would find in the desert sands. These old bones signified a time when Whales inhabited the now dry desert land. These bones can still be visited today in Cairo.

What threats does the Blue Whale face?

Whale calves often fall victim to Killer Whales and Sharks, but this is a natural threat. Human activity has caused the greatest damage to Blue Whale populations throughout the years. This long list of threats includes; habitat loss, pollution, boat traffic, fishing entanglement, krill depletion, and climate change.

According to the IUCN, the population of Whales is at risk due to Krill populations. With Global warming increasing, Blue Whales must travel longer distances for feeding grounds. This excess time spent looking for food leaves less time to reproduce, which impacts populations further.

Endangered Ranking – IUCN.

According to the IUCN Red List, the Blue Whale is classed as endangered. While the hunting of Blue Whale is now prohibited by the International Whaling Commission, significant damage has been inflicted on the population and it will take a long time to recover.

Why are they endangered?

Mankind’s relationship with our friends dates back 100+ years through the whaling industry. In fact, Blue Whales were given their name blåhval by the same Norwegian man who invented the exploding harpoon gun. The invention of this gun alongside the diesel-powered steamship made the Blue Whale an easier target.

For decades, Whale oil and blubber was used to power machinery. It was important to the industrial revolution to keep the whaling industry going. The near-extinction of multiple species caused a cessation of the whaling industry worldwide by 1980. It is estimated that 90% of Blue Whales were slaughtered before this occurred. This now leaves an estimated 10-25,000 left in the wild.

Why should you care?

Blue Whales play an important role in sea and on land. They are at the top of the food chain, and maintain populations of smaller fish, allowing room for marine plants and algae to grow. Without marine plants flourishing throughout the ocean, the Oxygen we breathe would be greatly impacted! Protecting Whales in our oceans protects the human race as well. This extends beyond the health of one species.

What can you do to help?

  1. Ethical Consumption: Commercial whaling is banned, but every year 1,500 large Whales are caught illegally. This is because traditional businesses still want to make pharmaceuticals out of Whale ingredients. There are also many countries that serve Whale meat as a delicacy because of its rarity on the market. Please ensure that any product you consume has come from a responsible source and does not contain even a trace of Whale.
  1. Spread the word! Reluctant to give up Whaling, countries like Japan, Iceland, and Norway still continue to practice it. If you suspect illegal whaling is happening in your community, ask your local representatives what they will do to protect them moving forward.
  1. Get Involved: Lastly, spend time signing petitions and getting involved in online spaces. Bringing widespread attention to the impact of Global Warming on Whale populations will further protect them. Ocean conservation projects are an amazing place to start.

If there is a public demand for change, then change will come. With everyone’s help, we can create new standards for the Ocean and all of its inhabitants! With safer habitats, we will hopefully see the Blue Whale populations stabilize.

Bethany MacDonald

Bethany MacDonald

Bethany MacDonald has contributed articles since 2020. As their Blog Lead, she specialises in informative pieces on culture, education, and language learning

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