The blue whale is known to be the loudest animal one the planet. It's calls can be heard over 600 miles away. Some scientists even believe that with the optimal conditions it can be heard a thousand miles away. Due to the massive amount of whaling that happened during the 1900's the population was reduced to as low as 9000 world wide. today it's estimated at best that the global population of these creatures is 24000 to 25000, a mere fraction of the estimated 300,000 blue whales that were around in the early 1900's. The blue whales heart is roughly the size of a VW bug, with arteries large enough for a child to crawl through. The blue whale is the largest and heaviest animal to ever live on planet earth, it even out weighs all known dinosaurs. Though the blue whale is very heavy it's body is designed for speed and easy movement through water. It's tapered body supports this fact. A female blue whale has only one child at a time. it is very rare for twins to every occur in blue whale populations. An infant blue whale drink up to 50 gallons of fat rich milk from there mothers a day. The blue whale has baleen for teeth which it uses to separate krill and other crustaceans from the water. Blue whales rarely are seen in groups of three or more. Blue whales feed in the northern seas and head south to the equator for breeding and birthing.