Killer WhalesWhales are giant creatures that live in the sea. They look like fish, but arenot. Whales belong to the group of animals called mammals.
Whales belong to thegroup of mammals called cetaceans, which comes from a Latin word meaning largesea animal. There are two major groups of whales. The first group is mysticeti(baleen whales), and the other isodontoceti (toothed whales). In the groupodontoceti, there is a family of whales called delphinidae (dolphins and smalltoothed whales). In this report, I will focus on a species of whale that comesfrom this family, and that species is the killer whale, or also known as orcinusorca, or just orca.Order now
The largest and most striking of the dolphin family, thekiller whale is one of the most fearsome predators of the deep. Killer whalesare basically the same shape as fish, but they differ in many ways. One of themost obvious differences is the tail fin. Fish have vertical tail fins, whilewhales have horizontal tail fins. One of the most distinctive features of orcasis the tall, wide dorsal fin located on its back.
In females, the dorsal fin cangrow to about 2 feet high. It is falcate (hooked or curved). In males, thedorsal fin is triangular in shape and can grow up to about 6 feet high. Anotherdistinctive feature of killer whales is that they possess a sleek, black andwhite pigmentation pattern. A white patch is located above and behind the eye. An extensive white ventral patch extends onto the flanks (sides).
“There is agray saddle behind the dorsal fin, which is black at birth. ” (Hoyt, Pg. 32) Atbirth, orcas are about 2. 1 to 2. 4 meters long and weigh about 180 kilograms.
When they are adults, males grow to about 9. 5 meters long weighing 8 tons ormore. Females grow to 8. 2 meters long and weigh 4-6 tons. “Orcas have robustand graceful bodies with a conical or rounded head. ” (Hoyt, Pg.
97) It has nodistinct beak. They have straight mouthlines. Another physical attribute ofkiller whales, besides having a tall dorsal fin, is that killer whales havelarge, paddle-shaped flippers. These flippers are 2-3 times larger in males thanthey are in females. Killer whales are very large physical specimens. Beingknown as a fearsome hunter with killer instinct, it would be interesting to knowwhat a killer whale’s diet consists of.
The orca resembles the great whiteshark in its predatory skill and range of food. They eat seabirds, turtles,fishes, including sharks, whales, dolphins, porpoises, seals, and sea lions. These hunters feed in groups of two to twenty animals. They can even kill baleenwhales much larger then themselves. They have 10 to 13 teeth on each side ofeach jaw, which helps in their feeding. Though killer whales sometimes attackdolphins, seals, and other whales larger than themselves, but they have not beenknown to attack people, although there have been documented cases of killerwhale attacks.
Throughout the ages, whales have lost some of the characteristicsof mammals. Mammals have hair covering their bodies. Whales have only a fewstiff hairs on their heads. Mammals have four legs.
A whale has no hind legs. The only traces that they remain are two tiny hipbones. The front legs havedeveloped into flippers, which are used for steering or keeping its balance. Although killer whales share the same characteristics as mammals, they also havespecial features that allow them to live in the water. Whales have many specialcharacteristics suited for living in the water. Living in water enables them toreach enormous sizes.
“The buoyancy (lift) of water helps support a whale’sbody, which makes it possible for them to grow larger. ” (Ellis ; Knoph,Pg. 18) Orcas have a highly streamlined shape. This enables them to swim with aminimum of resistance.
The powerful tail fins called flukes are horizontal. Whales swim by moving the flukes up and down. Another characteristic that ishelpful to killer whales, or any type of whale, is that a whale’s backbone,ribcage, and shoulder blades resemble those of other mammals. Almost all mammalshave seven neck vertebrae. In killer whales, these vertebrae are compressed intoa short length or joined together into one bone.
This keeps the head from movingabout. It also joins the head directly to the body. Orcas have smooth, rubberyskin that easily slips through the water. Mammals have hair to keep them warm.
Whales have only a few hairs on the head. To keep warm, they have a layer of fatcalled blubber. The blubber grows to about 6 inches thick never growing more. Ifthere is no food around or there is little food, killer whales can live offtheir blubber for a long time. Since blubber is lighter than water, thisincreases the buoyancy of whales. Much like their mammal brethren, whales havelungs and must come to the surface to breathe.
They can hold their breath forlong periods of time. Their muscles store more oxygen than the muscles of othermammals. Orcas store 41 percent of their oxygen supply in the muscles. Whendiving, the body reduces the blood flow to the muscles, still keeping a normalflow to the heart and brain. The heartbeat slows helping to save oxygen.
After adive, a killer whale must take several breaths to recharge its tissues withoxygen before diving again. When an orca comes up to breathe, it rolls forwardas it breaks the surface. This movement gives it only about two seconds to blowout and breathe in up to 2,100 quarts of air. They breathe through nostrilscalled blowholes.
These are located at the top of the head. Orcas have oneblowhole. Powerful muscles and valves open the blowhole wide so the whales canbreathe. Then they snap tightly shut. A cloud called a blow or spout is producedwhen a whale exhales. It consists of water vapor.
Sometimes it may include mucusand oil droplets. An interesting aspect of whales is that they utilize most ofthe five senses that humans use. The five senses are hearing, seeing, smelling,touching, and talking. Killer whales have no sense of smell and have pooreyesight. They have well-developed senses of touch and hearing. “Their keenhearing provides them with information about their surroundings.
“(International Experts, Encyclopedia survey, 1988) They can hear a wide range ofsounds, including low-and high-pitched sounds that are beyond the range of humanhearing. They can also tell from what direction a sound is coming from. Killerwhales produce sounds within the nasal sac system, a series of air-filledpouches around the blowhole. They locate underwater objects by listening forechoes produced when the objects reflect the sounds. They determine the distanceand the direction of an object through the echoes.
This is called echolocation. When researching any type of animal, it is also worth knowing the life span ofthe animal being researched. Knowing the life span of killer whales is usefulinformation that a researcher can later use. Knowing the life span of the killerwhale helps the researcher understand how the killer whale lives and how long itlives. The life span of killer whales is 50+ years for the males and 80+ yearsfor the females.
Human hunters account for many of the deaths. Except forpeople, whales have no natural enemies. Most of the whales that escape thehunter’s harpoon live to old age and die of natural causes. Some orcas die afterstranding themselves on a beach.
In some cases, a whale swims ashore alone. Inother cases, an entire pod of whales becomes stranded. People often returnbeached whales to the sea, but most swim back onto the beach. They cannot livelong out of the water. They may overheat, become crushed by their own weight, ordrown when the tide covers their blowholes. Another important aspect worthnoting is how killer whales reproduce.
The way that killer whales reproduce isvery unusual as compared to other mammals or even other whales. Killer whalesmate during a specific season. The male, called a bull, and the female, called acow, engage in playful courting as part of the mating process. The whales strokeeach other with their flippers during courting. Females breed at 9 to 10 yearswhile males breed at 16 to 17 years.
The gestation period or pregnancy periodlasts 13 to 17 months. A female will give birth every 10 years, sometimes every3 years. A whale has only one baby at a time. A baby whale is called a calf. Twins rarely occur. During birth one or more females may help the mother.
Whalesare already giant animals at birth. Calves are born in fall and winter. They are8 feet long and grow 4 inches every month. As soon as the baby is born, themother nudges it to the surface to take its first breath.
She stays close to itfor at least a year. During this year, the female will nurse her calf. She hasspecial breast muscles that pump milk into the baby’s mouth. “Whale milk ishighly concentrated and rich in fat, protein, and minerals.
” (Leatherwood& Reeves, Pg. 134) This helps the calves grow amazingly fast. Overall, thereare a plethora of characteristics and attributes that make killer whales unique. Whether it is the killer instinct, life span, or method of reproduction, it iseasy to see that killer whales are very special creatures. Though there are manydifferent kinds of whales, I chose to write about one specific species of whale:the killer whale or orcinus orca.
Whales are thought to be along the lines ofgentle of nonviolent. Killer whales, however, are neither. It is thesecharacteristics of the killer whale that many people find intriguing. Whales, ingeneral, are very unique creatures. The killer whale is unique in its own way,and possesses certain characteristics that most whales do not.
It is the killerinstinct found in killer whales that makes them intriguing and distinguishesthem from other species of whale.