You’d think such a massive creature would be an apex predator, but blue whales are actually gentle giants of the ocean. Let’s talk about twelve facts that make blue whales truly amazing.
1. Blue Whales Can Weigh More Than 300,000 Pounds
As the largest animal to have ever lived, blue whales can weigh more than 300,000 pounds and reach lengths of over 30 meters. That’s longer than 3 buses head to tail!
Just their tongues alone can weigh as much as an elephant and their blood vessels are so wide that you would swim down them!
2. They Are Found in Almost Every Ocean
With the exception of the Arctic Ocean, blue whales can be spotted in every other ocean on the planet. They usually move in groups of two to four, but larger groups have also been documented.
Blue whale populations tend to be more abundant in the Southern Hemisphere, especially in the waters of Antarctica. They seem to prefer cooler waters most of the time, but once the breeding season starts, whales will migrate to warmer regions to look for potential mates.
3. Their Lifespans Are Similar to Ours
In the wild, blue whales can live up to 80 to 90 years, although, it is estimated some are even older. Interestingly, a blue whale’s age can be approximated by their earwax! Over the course of their lives, blue whales make earwax with layers that build up gradually, similar to the rings in a tree. Each layer reflects different phases of a whale’s life, made up of different compositions and colors. Using these layers and assessing the length of the earwax plug, biologists can get a pretty good idea of how old a particular blue whale is.
4. Their Diet is Primarily Made Up of Krill
Blue whales feed almost entirely on krill, small shrimp-like crustaceans. Krill are a crucial source of nutrition for many animals, not just whales. Fish and seabirds also often feast on them.
You may have noticed that the inside of a blue whale’s mouth contains fringed structures that hang down from their upper jaws. While they may look like teeth, these are actually baleen plates. For their meals, a blue whale will take a huge gulp of water (hopefully containing lots of krill), close its mouth, and then use its tongue to expel the water. The plates trap the krill, acting essentially like a giant sieve!
5. Blue Whales Take Longer to Have Babies
Like cows, young blue whales are called calves. Scientists have many questions still about the life history of blue whales as they are very difficult creatures to study. Currently, it is believed that the gestation period (the time between conception and birth) of a blue whale is between 10 to 12 months.
6. They are One of the Loudest Animals Alive
To communicate with each other, blue whales use a variety of vocal sounds and signals. These vocalizations are very low in frequency and usually cannot be heard by human ears. However, they are extremely loud and can be heard by other big whales hundreds of miles away.
7. Humans Are the Biggest Cause of Population Decline
In the late 19th centuries, blue whales were heavily hunted by humans. It wasn’t until the 1960s that a global ban was implemented. Sadly, populations had already been decreased by 70 to 90 percent. Today, it is estimated there are only 10 to 25 thousand of these beautiful animals left in the wild.
8. They are Not Fish
Like all whales, blue whales are not actually fish despite their fish-like exteriors. Blue whales are mammals, just like humans! This means they are warm-blooded, breathe through lungs, and give birth to live young.
Generally, blue whales have to surface for air every 10 to 20 minutes. When they come up, they take a few deep breaths to fill their lungs then dive again. Their blowholes are located at the top of their heads and have a flap of muscle that seals off when the whale is underwater.
9. Blue Whales are Endangered Animals
While blue whales are not hunted today, they are still on the IUCN Red List and marked as an endangered species. They are slowly making a recovery in some areas due to international protection efforts, but they still face a number of challenges, including ship strikes, noise pollution, and environmental destruction.
10. They Do Not Form Lasting Bonds
Male blue whales produce songs to attract potential mates during the breeding season. After mating, they do not participate in the rearing of the young. Mothers and calves do not form lasting bonds either. A calf will usually stay with its mother for food and protection for about a year, then it leaves once it is able to fend for itself.
11. They Can Swim and Sleep
Blue whales don’t sleep for hours like humans do. They will take short naps throughout the day and night for rest using a method called unihemispheric slow-wave sleep (USWS). This means that they shut off one half of their brain while sleeping while the other half remains active. This allows them to keep breathing and swimming but also catch some much-needed snoozes.
12. They are Strong Swimmers
Blue whales will typically be seen cruising at speeds of 5 miles per hour when they are feeding and traveling. But when needed, they can reach speeds of over 20 miles per hour for short bursts. They are not the fastest swimmers but, because of their massive size, it takes a pretty significant threat to startle a blue whale.
