Killer Whales


Final Draft


Killer whales inhabit the cooler waters of both the western and northern hemispheres, where sea life is most abundant. Killer whales are mainly black or deep brown in color, having large white patches on their lower jaw, belly, and above their eyes, and a lighter off-white saddle patch just under and behind their dorsal fins. They are quite large mammals, with females growing to up to 8.5 m (27.5 ft) long, and males to up to 9.8 m (31.9 ft) long as they become fully-grown adults. All killer whales have a large dorsal fin protruding out of their mid-back, noting that the adult male\'s dorsal fin continues to grow until it is the shape of a triangular “sail” measuring up to 1.8 m (5.9 ft) tall. The flippers are also unique; they are large and oval shaped, making them unlike those of any other whale.


Killer whales mainly feed on fish, squid, and marine birds including penguins, seagulls and pelicans, though they may sometimes tackle a blue whale, the largest marine mammal on Earth!


In some parts of the world, killer whales are fussier about their diet; in the Pacific Northwest of the United States and Canada, for example, local populations of killer whale feed exclusively on salmon and trout while other groups of the same species feed on harbor seals, porpoises and sharks. Killer whales live in schools ranging in size from two to well over fifty members; they tend to cooperate during hunting.


In several places in the southern hemisphere, these whales sometimes rest briefly on shore as they rush to take seals or sea lions laying on the sand. Killer whales may scout a several hundred square kilometer area in search of prey, rapidly covering large areas in a matter of days!


Killer whales mate in the summer with several females, producing one offspring at a time, if mating was successful; the pregnant female becomes a male\'s mate. Studies show that killer whale groups are kind and caring, with males and females staying in their groups for life. Killer whales communicate by sending out sonar that bounce off prey and other objects and whose echoes allow whales to locate each other. They warn each other with rapid-fire clicks that sound like rasps and screams.


When on the prowl for marine mammals (which have very acute hearing underwater), killer whales can be remarkably silent for hours.


Humans have not hunted them extensively, (which is an improvement), although killer whales were hunted by various whaling operations. They are a valuable catch to many anglers who sell them to Zoos. Killer whales are highly trainable creatures due to their remarkable intelligence and affection to people. Killer whales are the largest member of the family Delphinidae; they are classified as Orcinus orca
Classification Table


Kingdom: Animal


Phylum: Chordate


Subphylum: Vertebrate


Class: Mammalia


Order: Cetacea


Sub-order: Odonceti Toothed Whales


Family: Delphinidae Dolphins and Porpoises


Sub-family: Orcinae


Genus: Orcinus


Species: Orca


Sources


1. "Orcas: Killer Beauties..."


http://www.geocities.com/ Gonzales, Steven. 1998


2. "Killer Whales" Microsoft Encarta Encyclopedia 2001. 1993-2000 Microsoft Corporation


3. "Whales and their habits" National Geographic. August 1998 Chadwick, Douglas Pg 178- 196


_____