Whales have largely been overhunted for decades, although many protections are in place to help promote population growth. That said, there are still some gigantic whales. Even more impressive than the size of the five biggest whales in the world is that most of them feed on tiny krill to maintain their mass.
The Bowhead Whale
Bowhead whales can reach up to 62 feet long and weigh up to 200,000 pounds, which makes them one of the largest whales in the world. Like many other large whales, they use baleen to feed.
Interestingly, bowhead whales live almost wholly in Arctic and subarctic waters. They have adaptations to keep from freezing, including a layer of blubber that can be more than a foot thick.
Scientists don't know precisely how long bowheads can live, but it appears that they can live for more than 200 years. Researchers have concluded this by finding stone harpoon tips lodged in bowhead whales' blubber. It's important to keep in mind that even though they have a long lifespan, they are endangered and have faced threats that include:
- Climate change
- Human threats from fishing vessels, oil drilling, and more
There are two major populations of bowhead whales: Western Arctic bowheads and Okhotsk Sea bowheads. The Okhotsk Sea population only has an estimated few hundred whales, making it much more threatened than the Western Arctic population.
The Right Whale
Right whales are not just one of the world's largest whale species but also the most endangered. Population estimates put correct whale numbers at fewer than 350 whales.
There are three major species of right whale:
- North Atlantic right whale
- North Pacific right whale
- Southern right whale
These whales use baleen to feed on small animals called krill, which they eat in large numbers.
Right whales can be as much as 52 feet long and 140,000 pounds. With their large size, plentiful fat, and large amounts of baleen, they got their name because whalers thought they were the "right" whale to hunt.
The Sperm Whale
Sperm whales are the biggest of the toothed whales, as opposed to using baleen. They can get up to a maximum of 65.6 feet. The International Union for Conservation of Nature (IUCN) classifies sperm whales as vulnerable animals.
Sperm whales live in just about any marine region but prefer deep water. Their prey of choice are deep-water squid, but they'll also eat sharks, octopi, and a variety of fishes.
Sperm whales have the largest brain of any living animal, weighing up to 9.2 pounds. These marine mammals also have quite an asymmetrical skull, which contributes to the animal having an angled blow spout out of its blowhole.
The Fin Whale
Size-wise, the fin whale is second only to the largest whale on our list. These incredible animals can grow to 85 feet and weigh up to 80 tons. They don't live as long as the bowhead whales, but 80 to 90 years is certainly respectable.
There are threats to fin whales that make them endangered, such as:
- Climate change
- Vessel strikes
Like many whales, they were over-hunted due to whaling, but conservation efforts are improving their outlook.
Fin whales use baleen to eat, and eat they do–around 2,000 kilograms (over 4000 pounds) each day! They also have a ridge behind the dorsal fin. That ridge has led to some people calling them razorbacks.
If you're looking for a fin whale, remember that they prefer cooler water. That said, they do live in all of the earth's oceans. Since they spend a lot of time in the open sea rather than closer to shore, they can be hard to track.
The Blue Whale
Blue whales are the biggest animals on the planet, reaching up to 110 feet long and weighing up to 200 tons! Their hearts alone are the size of a small car!
There are several subspecies of blue whales. The biggest is the Antarctic blue whale, easily weighing three times as much as the smaller North Atlantic and North Pacific blue whales. As big as they are, you might think they are easy to find, but that is not the case. Whalers overhunted populations, but the good news is that their numbers are increasing.
Blue whales use baleen to feed. They typically need to consume 4 tons of krill each day to survive.
You might find it hard to believe, but blue whales are one of the world's loudest animals and unleash groans that can be heard 1000 miles away. They use these sounds to communicate and navigate the ocean depths.