What is a Blue Whale?

The endangered blue whale has achieved the position of the single largest organism ever to live on Earth. Blue whales have baleen plates instead of teeth, migrate long distances, and communicate through vocalizations. Whaling during the early 20th century all but wiped out this magnificent animal.

As a mammal, a blue whale must breathe air, stay warm, and give birth to live young. It breathes through two blowholes at the top of its head, and usually a single breath lasts 15 minutes. Since blue whales are found in every major ocean, they migrate to follow the temperate current. During winter, they swim around the subtropical or temperate regions closer to the equator, but for summer they travel long distances to reach the cooler arctic regions.

The blue whale, or Balaenoptera, stretches an incredible 70-80 ft (21-24 m) on average, and weighs 90-150 tons (82-136 metric tons). These giant creatures need about 4 tons (3.6 metric tons) of krill, a type of shrimp, per day. They feed by filtering water through their baleen plates, catching tiny bits of food. If not caught in fishing nets, illegally harpooned by whalers, or adversely affected by pollution, a blue whale should live from 40-80 years.

The three species of blue whale look similar. The musculus lives in Northern oceans, the in the tropical zones, and the intermedia further down in the Southern hemisphere. They are bluish grey with wide tail flaps, called flukes. The splotches on their backs are so unique that they've been used by marine biologists to identify individuals. Those ridges along their neck that stretch from their chin to their stomach are called rorqual, for the Norwegian word for "furrows."

A blue whale breeds during the winter, every 2-3 years, while it fasts and lives on accumulated fat. After a gestation period of a year, a female will give birth to one calf that nurses for 6 months to a year. Gradually, the calf will transition to eating krill, but will probably stay with its mother for a couple of years for protection. It will reach sexual maturity when its 5-7 years old.

Sadly, the large populations of whales have dwindled in the last century due to new technology that made killing them easier for whalers. Along with pollution and other threats from mislaid fishing nets, the number of blue whales has plummeted to a few thousand. Many efforts, including limited whaling and regulated fishing, work to keep this whale from extinction.

The blue whale is the largest animal known to have ever existed, dwarfing even the most colossal dinosaurs. An adult blue whale can reach lengths of up to 100 feet (30 meters) and weigh as much as 200 tons. To put this in perspective, their tongue alone can weigh as much as an elephant, and their heart is the size of a small car, according to the World Wildlife Fund.

Blue whales primarily feed on tiny shrimp-like animals called krill. During feeding season, they can consume up to 4 tons of krill per day. They employ a method known as filter feeding, using their baleen plates to strain out water and retain massive amounts of krill, as reported by the National Oceanic and Atmospheric Administration.

Blue whales have a lifespan similar to humans, often living between 70 to 90 years, with some individuals even reaching over 100 years old. Their longevity can be attributed to their position as apex predators, with few threats in the ocean's vastness, aside from humans, as noted by marine biologists.

Yes, blue whales are currently classified as endangered. They were brought to the brink of extinction by commercial whaling in the 20th century, but their numbers have been slowly recovering since the international whaling ban in 1986. However, they still face threats from ship strikes, entanglement in fishing gear, and climate change, according to the International Union for Conservation of Nature (IUCN).

Blue whales communicate using a series of low-frequency pulses, groans, and moans that can travel vast distances underwater. These sounds are used for navigation, feeding, and social interaction. Some of their vocalizations are the loudest sounds made by any animal, and can be detected by others up to 1,000 miles away under ideal conditions, as studied by marine researchers.

Blue whales are found in all the world's oceans, except the Arctic, preferring deep, offshore waters. They migrate seasonally, feeding in polar regions during the summer and moving to warmer tropical and subtropical waters to breed and give birth in the winter. Their migratory patterns are complex and can vary greatly among different populations, as tracked by satellite tagging studies.