World's Largest Animal: How Big is a Blue Whale?

The blue whale is considered by scientists as the largest living animal in the world. It surpasses the size of other creatures alive today and even the majority of prehistoric animals, including the now-extinct oceanic predator megalodon, whose estimated size ranges up to almost 60 feet. Despite its gargantuan size, the blue whale is vulnerable to human activities and predators like orcas or killer whales.

Blue whales (Balaenoptera musculus) are found across all of Earth's oceans except the Arctic Ocean. In the northern hemisphere, they are regularly spotted in the Gulf of St. Lawrence, as well as off the coasts of Monterey, California, and Baja California, Mexico. In the southern hemisphere, these massive marine mammals and baleen whales live in the Southern Ocean, around the icy continent of Antarctica.

How Big is a Blue Whale?

Blue whales, as mentioned earlier, are the world's largest animals simply because they can grow at a length of up to 90 feet weighing more than 100,000 pounds; this has been observed in the North Atlantic Ocean and North Pacific Ocean, according to the National Oceanic and Atmospheric Administration Fisheries (NOAA Fisheries).

Meanwhile, in Antarctic waters, these marine animals can grow of up to 110 feet and weigh over 330,000 pounds, says the NOAA Fisheries, adding that female blue whales are generally larger than their male counterparts, like many other baleen whales. To give a complete picture, scientists estimate that the size of blue whales is comparable to a full airplane or three long school buses.

Why Did Blue Whales Get So Big?

No one alive today witnessed first-hand the transition of blue whales from small animals into its giant form that we know today. However, ancient fossils show that it was evolution and biology, as well as the abundance of food resources that paved the way for blue whales to get so big. This phenomenon occurred approximately 10 million to 5 million years ago, according to scientists.

Multiple sources show that the blue whale is not only the world's biggest living animal but to have ever existed. In August 2023, a media release from the University of Pisa in Italy revealed that a giant ancient whale that lived 40 million years ago is larger than the blue whale. This prehistoric monster is called Perucetus colossus, which means colossal whale from Peru.

Global Blue Whale Population

Formidable as they may seem and having an average lifespan of 80 to 90 years, blue whales are on the brink of a dwindling population, which is depleted by commercial whaling activities globally. As a result, these sea creatures are protected under the Endangered Species Act and Marine Mammal Protection Act.

According to the World Wide Fund for Nature (WWF) Australia, there may have been as many as 250,000 blue whales before whaling. Currently, the global blue whale population is estimated to be between 10,000 and 25,000, with the majority of biologists considering the species B. musculus as the most endangered among the great whales on Earth, WWF Australia says.