Before the whaling industry of the 19th and 20th centuries hunted them to near extinction, blue whales were common in almost all the world’s oceans. The largest populations were found in Antarctica’s waters, where it is estimated that over a quarter of a million of these incomprehensibly large mammals lived. A 2002 report estimated that there are now between 5,000 and 12,000 blue whales left in the world—and around 2,000 inhabit Antarctica.
The blue whale has a long, thin, tapering body that when compared to other whales stockier frames, appears almost stretched. The dorsal fin is small, less than a foot high. Due to their immense size, it is often difficult to weigh them accurately or even comprehend their
vastness. They are thought to weigh between 160,000 and 300,000 pounds, the largest animal ever known to exist. The largest known specimen is thought to have weighed over 400,000 pounds. At birth, calves weigh around 6,000 pounds, about the size of an adult male
hippopotamus. Females are generally longer than males, though males weigh more due to their heavier bones. In their adolescence, calves can grow as much as 200 pounds per day. Due to their immense size, several of their organs are also the largest ever recorded.
For example, the tongue of a blue whale weighs around 6,000 pounds.
Blue whales do not form the large groups seen in other whale species. They most commonly live alone or occasionally with one other partner, though it is not known for how long such relationships last. This relatively solitary existence carries them through their long lives, as scientists estimate that blue whales can live as long as 80 years.
They are also known to sing, though no one completely understands why. Some reasons suspected are individual recognition, contextual information such as feeding, courtship, and alarm, and location of prey.
FUN FACT: Though having a mouth able to hold over 100,000 pounds of food, a blue whale cannot swallow anything wider than a beach ball at one time.