Orcas

Orcas are also known as killer whales. They should be killer dolphins because orcas are dolphins, not whales. Grown up orcas can be as large as 9m.There are lots of types of orcas. They live around the world, some of them in permanent places, others emigrating every year.

Orca’s nature

Orcas are white and black. The white dot on their heads is not an eye (I also thought it was so until I found out on a book). They have a dorsal fin as high as 2m in some males. An adult orca, has to eat 225 kilograms of food every day, only to survive.

They are mammals (they have to breath outside the water), orcas normally die when they try to get a seal, because even a slight miscalculation can get them stranded.

Hunting strategies

The hunting strategies orcas employ, are very advanced. One of them starts with one orca, 15m away from the shore; when the orca detects the seal, she starts to swim as fast as he can towards it. When the orca is nearly in the shore, she swims the last meters, and comes into the beach with a movement called intentional stranding. Then she kills the seal with her jaws, almost the force of 4 lions jaws!

In fact, orcas have a very strong back muscle. It as strong it can produce 108 HP (80.5 kW).

Orca pods

But orcas travel in groups called pods. A big pod is powerful enough to kill great baby whales, protected by an adult mother great whale.

When a pod of orcas want to catch a animal, they can persist until they get it, and some attacks can last even over 2-3 h.

Pods are usually led by mothers, or by grandmothers, that pass their leading knowledge to the young ones.

Ultrasounds

Ultrasounds are their most interesting technique. They communicate by ultrasonic pitched sounds. Also the have a sonar that can detect fish 2 miles away. It helps them to detect their preys.