Orcas

– Killer Whales Essay, Research Paper

Killer whales are one of the most fascinating displays of ocean life. The killer whale has characteristics that are important to its survival in the ocean. It is interesting to know that killer whales have a plentiful diet. It is astounding to see how killer whales behave in the ocean. I plan to tell you about the killer whale, its characteristics, its diet, and its behavior in the ocean as well as the predation of the orca.

Orcinus orca is the scientific name for the massive marine mammal. Orcas are not rare, but have declining numbers in some areas (Martin.) Orcas are found from the Artic Ocean to the Antartic Ocean. (Britannica) They belong to the Delphinidae, or dolphin family, which is the largest of their species. Female orcas grow to be at the most 15 feet, and weigh up to 4 tons, but the males can grow as large as 20-30 feet, and weight up to 8 tons. (Martin) The color of the orca is white in some spots, black on the majority of the body, and gray just behind the dorsal fin. It is white on the chin, belly and the eye. The white patch above the eye is usually mistaken for the eye, and may confuse their prey, but acts as a camouflage for the eye. The name “killer whale” makes people tend to believe that this is a viscious man-eating mammal, yet it is one of the most shrewd, docile and playful species of the marine mammals. The orca is sexually mature at 10-15 years of age, much like humans, which is 12-13 years of age. They tend to mate year round, and is able to have a calf every two years. It is interesting to know that lactation of the mother lasts 12 or more months (Wynne.) The life expectancy of orcas is 45-50 years of age.

The orca has some distinctive features. The dorsal fin is a feature of the orca that is the most humorous because it is almost always mistaken for a shark when the orca is submerged and the dorsal fin is exposed. The dorsal fin is triangular, and has been know to grow in excess of 6 feet in length on males, but grow no more than 3 feet on females. (Martin) The pectoral fins of the orca can measure up to one sixth of it’s body length and is in the shape of a paddle. The orca usually have 40-50 conical teeth which measure over 2 inches in length, and has a perfect fit with the opposite set which makes it an excellent hunter. Although the teeth are robust, they do a lot of work through the years because older orcas have been known to have teeth worn down to the gum tissue (Haley.) The tongue of a killer whale has been known to weigh in excess of 2 tons (Martin.) They have been known to be fearless hunter, and a fast predator. Some say the ferocity of the killer whale exceeds that of the great white shark, which makes it one of the most feared in ocean life.

Orcas have the most diverse diet of all the marine mammals. Some specimens of orcas prefer different types of marine mammals or marine life. They will mostly eat fish and squid, but will devour almost any marine animal in site. They tend to eat a wide array of fish from salmon, hering, halibut, and cod. One Orcas was found to have a harbor seal, a stellar sea lion, and a harbor porpoise in its stomach. Another orca was found to have the remains of 32 adult harbor seals in its belly (Martin.) The orca has been observed to eat river otters, squid, and different species of marine birds. In packs, the orcas have been known to prey on humpback whales tearing away in different angles. Orcas have also been known to swim close to shore and grab a harbor seal. It is interesting to know that the killer whale is known to hunt by sound or sonar. The different types of food it ingests make the orca one of the most diverse cetaceans known.

The behavior of the orca is remarkable. The Orca lives in large groups of 50, and swim in a formation of a line or row. They occasionally leap out of the water. Orcas have been known to stay around the area where another orca has been captured, engaging in conversation. The biggest of a pack or family of whales is usually the male. It leads the pack and has been known to divert the attention of hunters and would be captured in its place. In captivity, the Orca is usually well trained in performing tricks and is cery friendly to humans. It is surprising to know that the killer whale will share a pool with dolphins, which is a natural prey of the orca. Places such as Six flags Marine World, and Sea world have recruited and cared for the Orcas for entertainment purposes. Tricks of the orca include kissing people, jumping through hoops, balancing people on their noses, and most importantly, splashing people. In captivity, they are well taken care of.

Killer whales have no real predators but man himself. Whales have been known to be used for it’s meat and oil. Killer whales have taken a liking to black cod in the Alaskan ocean, and have paid dearly for it; fishermen in Alaska have punished the orcas by shooting it. Although this is very common in Alaska, it is not legal. The intelligence of this mammal is one that proceeds that of any other marine life form because of its hunting style and performance under supervised training. It is one of the most caring of animals and have been known to circle its dead for hours until dying itself. It puts its own life on the line when the others in its group is in trouble. The diverse diet also makes it an interesting marine mammal to know about because different types of marine life have a food staple consisting of two or three species. The orcas distinctive white spot above the eye make for good diversion and the conical teeth make for excellent hunting. And although they range in size depending on sex, the fascination with this fair sized marine mammal is immeasurable in size.

Martin, Richard Mark Mammals of the Ocean. G.P. Putnam’s Son New York, 1977

Britannica Online Dictionary. Britanica.com. June. 2001

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Wynne, Kate Marine Mammals of Alaska University of Alaska Fairbanks. Pub Date:

Unknown

Haley, Delphine Marine Mammals. Pacific Search Press Pub. Date: unknown