Orca / Killer Whale

Orcinus orca

Main Characteristics

Orca or Killer Whales are the largest species of the dolphin family. They have avvery robust body with a distinctive black-and-white colour and a grey saddle patch behind the dorsal fin. The head is big, conical and lacks a well-defined beak. The dorsal fin, situated mid-back, is large (up to 1,8m in males), prominent and variable in shape: curved in females and juveniles, erected and almost spike like in adult males. The flippers are large, broad and rounded. The differing shape of the dorsal fin and the saddle patch are used to identify individuals. The rather impressive dentition consists of 20 to 28 large pointed teeth in either jaw.

Bahaviour and Diet

Orcas are fast swimmers capable of reaching a speed of 50 km/h. Water surface behaviours such as breaching, spy-hopping, and flipper-slapping are fairly common. Being very social animals, they live in stable groups, called pods, with strong family ties. The world population consists of subpopulations that are specialized to the resources available within the range respectively. Orcas are known for their well organized hunting techniques and for developing specific vocalizations within the pods. The varied diet and vivid chase of other marine mammals makes them the top predators in the oceans and gave them the common name "Killer Whale".

Whales in Captivity, Keiko

Orcas are one of the best-studied whale species worldwide, which is the result of extensive research in the wild, but also on animals in captivity, which allows easy long-term observations. The discussion on whether or not to have cetaceans in captivity reached its peak with Keiko, the Orca in the Free Willy movies, who's pitiable condition led to a big movement for his release into the wild, and increasing public awareness on the situation of cetaceans in Oceanaria. 

Distribution and Migration

Considered the most widespread cetacean, Orcas are not limited by habitat conditions such as water temperature or depth. Their movements appear connected to the favoured prey and the largest populations can generally be found in higher latitudes. This species was not hunted as much as other whales, but has often been caught for display. The biggest threat is heavy ship traffic, toxins in the water and reduced prey abundance. The worldwide population size is unknown.

To learn more about Orcas or Killer Whales visit Wikipedia or The America Cetacean Society.