The killer whale:

The killer whales or Orca are one of the largest mammals in the oceans. They belong to the oceanic dolphin family and they are the largest of the dolphins. The orcas can be found in so many oceans and seas.

The killer whales are well-known for their black back and white chest and patch above and behind the eyes. The Orcas' babies are born with a kind of yellow or orange tint but it goes away and becomes white. The killer whales can grow to 6-8 meters long for males and the females are from 5-7 meters long. The male orca weighs around 6 tons and the female orca weighs around 4 tons. The calves weigh 180kg and they are about 2.4 meters long when they are first born. Never mind the size of the killer whales, they are the fastest mammal in the water; they can reach 30 knots which equals 56km/h. The killer whales use the echolocation to communicate with each other. They also use it for hunting too. It’s like what bats do, sending sound waves until they bounce back and they can tell the location and the size and shape of the object.

The killer whales' worldwide population is estimated to be less than 50,000 in different parts of the world. They feed on different type of marine animals and they are considered one of the most dangerous predators in the water. They feed on fish, seals, sea lions, birds and sometimes on sharks and whales. They hunt in a group called pods. The pod contains up to 40 killer whales and that’s why some of their prey can be sharks or whale so they can take them out fast and easy.

Killer Whale." Wikipedia, the Free Encyclopedia. Web. 07 Jan. 2012. <http://en.wikipedia.org/wiki/Killer_whale>.

Killer Whales (Orcas), Killer Whale Pictures, Killer Whale Facts - National Geographic." Animals - Animal Pictures - Wild Animal Facts - Nat Geo Wild - National Geographic. Web. 07 Jan. 2012. <http://animals.nationalgeographic.com/animals/mammals/killer-whale/>.