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Facts About Blue Whale Adaptations and Survival

Blue whales have changed a lot since their ancestors lived on land. Their most famous characteristic, their enormous size, is possible only in a watery environment. They have numerous other physical and behavioral adaptations for survival. Blue whales are well adapted to natural conditions, although they were not able to cope with commercial whaling. After humans nearly wiped out the species in the 20th century, protection efforts have led to populations of blue whales gradually recovering.

Size
- Blue whales are well known as being the largest living animals on the planet. They reach a length of over 100 feet. Such a huge size has advantages in the oceans. It means that very few predators are a threat. The only natural predators of the blue whale are orcas, and possibly the largest sharks. Even orcas have to work as a group to take down a blue whale calf. Size also reduces the surface area-to-weight ratio of an animal, letting it retain more heat. This is useful particularly in polar waters, where blue whales spend much of their time.
Feeding
- Large animals also can store more energy as fat. Blue whales eat a great deal when food is plentiful, and then are able to go without eating for a long time. Blue whales filter out huge numbers of tiny creatures, notably krill, from the water. They do this with the aid of baleen plates, fringes in their mouths that trap small creatures from the water. A blue whale gulps a great quantity of plankton-rich water and expels it through the baleen plates with its tongue, thus trapping all the food items.
Navigation and Communication
- Blue whales are highly vocal, emitting sounds that can travel hundreds of miles. These sounds are used for communication and also may be used for echolocation in the murky ocean habitat. Echolocation enables an animal to build up a picture of its surroundings using sound, and has been well studied in bats and toothed whales, but not so much in baleen whales.
Behavior and Reproduction
- Blue whales rarely form large social groups. They usually swim alone or with one other whale. Occasionally they congregate in larger groups of 50 or more individuals, usually in exceptionally food-rich waters. Blue whales form short-term couples during the breeding season. A male and a female whale stay together for as long as five weeks, according to the Encyclopedia of Marine Mammals. The purpose of this behavior is unknown. Females give birth once every two or three years. A female blue whale is pregnant for a year before giving birth and when the baby is born, it already weighs three tons, which gives it a good start in life. The calves stay with their mothers for months, with the mothers providing milk as well as protection from potential predators.

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