The Orca Killer Whale
The orca whale is a streamlined killing machine that can weigh over 13,500 lbs. It has been known to swim over 30 mph. It's the only whale to hunt other warm blooded animals.
The orca, or killer whale, has the broadest diet of any large ocean predator. It is the most feared of all the toothed whales, and few marine creatures are safe from its jaws. There are 20 to 26 conical teeth in each jaw. The teeth curve backward and inward to seize prey and tear it into chunks. The orca produces sounds from a nasal flap it its air passages and flexes muscles it its forehead to focus the sounds into a beam. It analyzes the echoes that bounce back from objects hit by the beam to discover the direction and range of prey. The orca's muscular tail flukes propel him at high speed. The tail is also used to slap the water and produce deafening sount that may stun schools of fish ito immobility.
The orca can be found in all the world's oceans and seas from the equator to both polar regions.
Although the orca can feed and breed in warn and cool water, the orca usually stays in one area all year, but within it's home range it travels widely in search of prey.
The orca lives in a tigh knit group that usually includes a female with her calves, older infertile females, and an adult male. One or more of these form the basis of a family unit known as a pod. Pod member use a range of whistles, tones and screams to keep in touch with each other. The orca generates a beam of sound pulses from its forehead to use as a form of sonar in navigating and hunting dark water. The whale can tell from the echo exactly what lies in its path- A fellow pod member, a rocky outcrop or something edible.
An orca may breed with several mates from other pods, and as a result, males cannot tell which calves they fathered. So, to make sure they care for related young, they look after the calves in their pod; these will almost always be the oppspring of their sisters. Almost a year and a half after mating, a female orca gives birth to a calf. Born tail first in shallow water, the calf is nudged to the surface by its mother to take its first breath. For the first few weeks, the calf suckles two ot three times every hour. The calf will suckle for about two years, forming a powerful bond with its mother. Because of the care the calf receives, the mother's birth interval is long, averaging six years.
The orca isn't widely hunted, but some are still killed by fishermen. Long term threats are coastal pollution and the reduction of the orca's prey through overfishing, although there are no fears for species survival.