Issuu on Google+

W

s e l ha


C ontents Introduction Anatomy of a Whale Evolution of Whales Types of Whales Blue Whale Humpback Whale Sperm Whale Killer Whale Beluga Whale Whale Behaviour Where Whales Live

3 4 8 14 16 18 20 22 24 26 28


Introduction

Whales are large, intelligent, aquatic mammals. They breathe air through blowholes into lungs (unlike fish who breathe using gills). Whales have sleek, streamlined bodies that move easily through the water. They are the only mammals, other than manatees (seacows), that live their entire lives in the water, and the only mammals that have adapted to life in the open oceans.


Anatomy of a Whale

A whales anatomy is composed of many parts including their blowhole, teeth (toothed whales), plates (baleen whales), dorsal fin, flipper, flukes, eyes and ears.

Blowhole Ear Eye

Flipper


Dorsal Fin Fluke

Genital Slit


Blowhole

Whales are marine mammals and like all mammals they require oxygen to survive. Unlike other sea creatures such as fish a whale would suffocate in water if it did not have a blowhole for oxygen. The blowhole is situated on or near the top of their head and acts as an airway passage for breathing.

Teeth

Toothed whales are typically smaller than baleen whales (whales without teeth) and have a single blowhole on their head as compared to the two blowholes found on a baleen whale.

Whales cannot breathe through their mouth because the esophagus (food passage) and trachea (oxygen passage) are completely separated from each other.

Their teeth can vary greatly amongst each sub order of the species, and some may not even use their teeth for eating.

Although whales must breathe oxygen they can spend up to 90% of their lives underwater.

Some whales such as the sperm whale are believed to use their teeth mainly to show aggression.

Flukes

The flukes are attached to the end of the whale and are used for propulsion. Unlike sharks however whales move forward by flexing their tail up and down, not left and right.

Baleen whales have rows of plates that resemble the teeth of a comb located on the top of their jaws for feeding instead of teeth. Instead of enamel a whales teeth is covered in cementum cells. Unless the cementum is worn down you won’t be able to see the enamel on their teeth.


Dorsal fin

The main purpose of the dorsal fin is to stabilize the whale and keep it from rolling in the water.

Eyes

The eyes of a whale are relatively small when compared to the rest of its body.

Some whales such as the (Orca) killer whale have a dorsal fin while others such as the beluga whale do not.

Their eyes are well adapted to aquatic life and secrete an oil used to lubricate protect their eyes from debris and other chemicals in the ocean.

Fins can also vary greatly in shape and size depending on the species of whale.

They are not capable of secreting tears as humans do, but their cries can be heard vocally miles away.

Almost all whales have a dorsal fin with the exception of a rare few such as the sperm whale.

Flipper

The flippers on a whale are used to help navigate and steer in the ocean. They use their flippers to perform various aquatic acrobatics such as steering left and right by changing the angle of their flippers and helping to provide lift so they can rise in the water and control their level of aquatic depth better. The flippers are controlled by strong pectoral muscles and can vary in size with each species.

Ears

The ears on a whale are designed differently than a humans ears and are well adapted to marine (aquatic) life. For a whale there is little difference between the inner and outer ear area, instead of receiving sound through the outer ears whales receive sound through their throat, the sound than passes through a cavity and into the inner ear.


Evoultion of Whales

The evolution of whales has been a mystery. How did a large, big-brained mammal -- airbreathing, warm-blooded, giving birth to live young -- come to live entirely in water, when mammals evolved on land? The discovery of many fossils with transitional features documents the transformation of whales from land animals to ocean dwellers. Another indication of whales’ evolutionary heritage can be seen in the way they move.


C

all it an unfinished story, but with a plot that’s a grabber. It’s the tale of an ancient land mammal making its way back to the sea, becoming the forerunner of today’s whales. In doing so, it lost its legs, and all of its vital systems became adapted to a marine existence -- the reverse of what happened millions of years previously, when the first animals crawled out of the sea onto land. Some details remain fuzzy and under investigation. But we know for certain that this back-to-the-water evolution did occur, thanks to a profusion of intermediate fossils that have been uncovered over the past two decades.

the oldest known whales. The new bones, dubbed Pakicetus, proved to have key features that were transitional between terrestrial mammals and the earliest true whales. One of the most interesting was the ear region of the skull. In whales, it is extensively modified for directional hearing underwater. In Pakicetus, the ear region is intermediate between that of terrestrial and fully aquatic animals. Another, slightly more recent form, called Ambulocetus, was an amphibious animal. Its forelimbs were equipped with fingers and small hooves. The hind feet of Ambulocetus, however, were clearly adapted for swimming. Functional analysis of

Pakicetus

Approx. 52 Million Years Ago

In 1978, paleontologist Phil Gingerich discovered a 52-millionyear-old skull in Pakistan that resembled fossils of creodonts -- wolf-sized carnivores that lived between 60 and 37 million years ago, in the early Eocene epoch. But the skull also had characteristics in common with the Archaeocetes,

its skeleton shows that it could get around effectively on land and could swim by pushing back with its hind feet and undulating its tail, as otters do today. Rhodocetus shows evidence of an increasingly marine lifestyle. Its neck vertebrae are shorter, giving it a


Ambulocetus Approx. 49 Million Years Ago

less flexible, more stable neck -- an adaptation for swimming also seen in other aquatic animals such as sea cows, and in an extreme form in modern whales. The ear region of its skull is more specialized for underwater hearing. And its legs are disengaged from its pelvis, symbolizing the severance of the connection to land locomotion. By 40 million years ago, Basilosaurus -- clearly an animal fully adapted to an aquatic environment -- was swimming the ancient seas, propelled by its sturdy flippers and long, flexible body.

Yet Basilosaurus still retained small, weak hind legs -- baggage from its evolutionary past -- even though it could not walk on land. None of these animals is necessarily a direct ancestor of the whales we know today; they may be side branches of the family tree. But the important thing is that each fossil whale shares new, whale-like features with the whales we know today, and in the fossil record, we can observe the gradual accumulation of these aquatic adaptations in the lineage that led to modern whales.

Basilosaurus Approx. 37 Million Years Ago


Types of Whales

Whales typically fall into one of two sub categories: baleen whales and toothed whales. There are several characteristics that differentiate the two types of whales include their size, social structure, breathing (number of blowholes), dentition (teeth or baleen plates) and echo location vs song.

Blue Whale

Fin Whale

Sperm Whale

Right Whale

Beaked Whale


Bryde’s Whale

Minke Whale Sei Whale

Long-finned Pilot

Humpback Whale

False Killer Whale Narwhal

Bowhead Whale

Orca

Grey Whale

Bottlenose Whale

Pilot Whale

Beluga

Human Size


Toothed Whales Toothed whales as you probably guessed it have teeth (instead of baleen plates) used for eating and include whales such as the Orca (killer whale), sperm whale, bottlenose whale and beluga whale among others.

Dolphins and porpoises also fall into the toothed whale category. These type of whales have a single blowhole as compared to the two blowholes found in baleen whales. The majority of toothed whales (with the exception of the sperm whale) are smaller than their baleen whale relatives, but are known for eating larger prey from fish to sea lions and all the way up to small whales. Due to their smaller size some species of whale (excluding killer whales) also stand a greater chance of being hunted and attacked. This type of whale also tends to have much larger and more sophisticated social structures as compared to baleen whales. Toothed whales make sounds using their blowholes and are not born with vocal cords. They also have very well-developed echo location abilities that they use to locate food and find other objects in the ocean. Male toothed whales tend to be larger than their female counter parts.


Baleen Whales

Baleen whales aka great whales have baleen plates (which resemble the bristles of a comb) instead of teeth and filter food through their baleen plates while allowing water to pass through. Filter feeding is a method in which they swim with their mouth open and allow prey such as fish and squid to get caught and stuck in their baleen plates as opposed to using teeth. Baleen whales typically eat small prey such as fish, krill and plankton which is partly due to have baleen plates instead of teeth which could be used for chewing. This group of whales is (for the most part) larger than their toothed whale relatives and include whales such as the gray whale, humpback whale, blue whale, and bowhead whale. Baleen whales have two blowholes used for breathing instead of one. Among the species is the blue whale which is considered the largest known mammal on this planet and can grow as large as 110 feet. Female whales are typically larger than their male counter parts. Baleen whales tend to prefer traveling in small groups (pods) or alone. In the past the humpback, bowhead and right whale (among others) were hunted largely for their oil, which was considered useful for making cooking oils.


Blue Whale

Blue whales are the largest animals ever known to have lived on Earth. These magnificent marine mammals rule the oceans at up to 100 feet (30 meters) long and upwards of 200 tons (181 metric tons). Their tongues alone can weigh as much as an elephant. Their hearts, as much as an automobile. Blue whales reach these mind-boggling dimensions on a diet composed nearly exclusively of tiny shrimplike animals called krill. During certain times of the year, a single adult blue whale consumes about 4 tons (3.6 metric tons) of krill a day. Blue whales are baleen whales, which means they have fringed plates of fingernail-like material, called baleen, attached to their upper jaws. The giant animals feed by first gulping an enormous mouthful of water, expanding the pleated skin on their throat and belly to take it in. Then the whale’s massive tongue forces the water out through the thin, overlapping baleen plates. Thousands of krill are left behind—and then swallowed. Blue whales look true blue underwater, but on the surface their coloring is more a mottled blue-gray. Their underbellies take on a yellowish hue from the millions of microorganisms that take


up residence in their skin. The blue whale has a broad, flat head and a long, tapered body that ends in wide, triangular flukes. Blue whales live in all the world’s oceans occasionally swimming in small groups but usually alone or in pairs. They often spend summers feeding in polar waters and undertake lengthy migrations towards the Equator as winter arrives.

These graceful swimmers cruise the ocean at more than five miles an hour (eight kilometers an hour), but accelerate to more than 20 miles an hour (32 kilometers an hour) when they are agitated. Blue whales are among the loudest animals on the planet. They emit a series of pulses, groans, and moans, and it’s thought that, in good conditions, blue whales can hear each other up to 1,000 miles (1,600 kilometers) away. Scientists think they use these vocalizations not only to communicate, but, along with their excellent hearing, to sonar-navigate the lightless ocean depths.

Fast Facts

Type: Mammal Diet: Carnivore Size: 82 to 105 ft (25 to 32 m) Weight: Up to 200 tons (181,437 kg) Group name: Pod Protection status: Endangered


Fast Facts

Type: Mammal Diet: Omnivore Size: 48 to 62.5 ft (14.6 to 19 m) Weight: 40 tons (36 metric tons) Group name: Pod Protection status: Endangered


Humpback Whale

Humpback whales are known for their magical songs, which travel for great distances through the world’s oceans. These sequences of moans, howls, cries, and other noises are quite complex and often continue for hours on end. Scientists are studying these sounds to decipher their meaning. It is most likely that humpbacks sing to communicate with others and to attract potential mates. These whales are found near coastlines, feeding on tiny shrimp-like krill, plankton, and small fish. Humpbacks migrate annually from summer feeding grounds near the poles to warmer winter breeding waters closer to the Equator. Mothers and their young swim close together, often touching one another with their flippers with what appear to be gestures of affection. Females nurse their calves for almost a year, though it takes far longer than that for a humpback whale to reach full adulthood. Calves do not stop growing until they are ten years old. Humpbacks are powerful swimmers, and they use their massive tail fin to propel themselves through the water and sometimes completely out of it. These whales, like others, regularly leap from the water, landing with a tremendous splash. Scientists aren’t sure if this breaching behavior serves some purpose, such as cleaning pests from the whale’s skin, or whether whales simply do it for fun.


Sperm Whale

Sperm whales are easily recognized by their massive heads and prominent rounded foreheads. They have the largest brain of any creature known to have lived on Earth. Their heads also hold large quantities of a substance called spermaceti. Whalers once believed that the oily fluid was sperm, but scientists still do not understand the function of spermaceti. One common theory is that the fluid—which hardens to wax when cold—helps the whale alter its buoyancy so it can dive deep and rise again. Sperm whales are known to dive as deep as 3,280 feet (1,000 meters) in search of squid to eat. These giant mammals must hold their breath for up to 90 minutes on such dives. These toothed whales eat thousands of pounds of fish and squid—about one ton (907 kg) per day. Sperm whales are often spotted in groups (called pods) of some 15 to 20 animals. Pods include females and their young, while males may roam solo or move from group to group. Females and calves remain in tropical or subtropical waters all year long, and apparently practice communal childcare. Males migrate to higher latitudes, alone or in groups, and head back towards the equator


to breed. Driven by their tale fluke, approximately 16 feet (5 meters) from tip to tip, they can cruise the oceans at around 23 miles (37 kilometers) per hour. These popular leviathans are vocal and emit a series of “clangs” that may be used for communication or for echolocation. Animals that use echolocation emit sounds that travel underwater until they encounter objects, then bounce back to their senders— revealing the location, size, and shape of their target. Sperm whales were mainstays of whaling’s 18th and 19th century heyday. A mythical albino sperm whale was immortalized in Herman Melville’s Moby Dick, though Ahab’s nemesis was apparently based on a real animal whalers called Mocha Dick. The animals were targeted for oil and ambergris, a substance that forms around squid beaks in a whale’s stomach. Ambergris was (and remains) a very valuable substance once used in perfumes.

Fast Facts

Type: Mammal Diet: Carnivore Size: 49 to 59 ft (15 to 18 m) Weight: 35 to 45 tons Group name: Pod Protection status: Endangered


Fast Facts

Type: Mammal Diet: Carnivore Size: 23 to 32 ft (7 to 9.7 m) Weight: Up to 6 tons (5,443 kg) Group name: Pod Protection status: Endangered


Killer Whale (Orca) Orcas, or killer whales, are the largest of the dolphins and one of the world’s most powerful predators. They feast on marine mammals such as seals, sea lions, and even whales, employing teeth that can be four inches (ten centimeters) long. They are known to grab seals right off the ice. They also eat fish, squid, and seabirds. Though they often frequent cold, coastal waters, orcas can be found from the polar regions to the Equator. Killer whales hunt in deadly pods, family groups of up to 40 individuals. There appear to be both resident and transient pod populations of killer whales. These different groups may prey on different animals and use different techniques to catch them. Resident pods tend to prefer fish, while transient pods target marine mammals. All pods use effective, cooperative hunting techniques that some liken to the behavior of wolf packs. Whales make a wide variety of communicative sounds, and each pod has distinctive noises that its members will recognize even at a distance. They use echolocation to communicate and hunt, making sounds that travel underwater until they encounter objects, then bounce back, revealing their location, size, and shape.


Beluga Whale Belugas are also called white whales, and their unusual color makes them one of the most familiar and easily distinguishable of all the whales. Calves are born gray or even brown and only fade to white as they become sexually mature around five years of age. White whales are smallish, ranging from 13 to 20 feet (4 to 6.1 meters) in length. They have rounded foreheads and no dorsal fin. Belugas generally live together in small groups known as pods. They are social animals and very vocal communicators that employ a diversified language of clicks, whistles, and clangs. Belugas can also mimic a variety of other sounds. These whales are common in the Arctic Ocean’s coastal waters, though they are found in subarctic waters as well. Arctic belugas migrate southward in large herds when the sea freezes over. Animals trapped by Arctic ice often die, and they are prey for polar bears, killer whales, and for Arctic people. They are hunted by indigenous people of the north, and by commercial fisheries that brought some populations, such as those in the Gulf of St. Lawrence, to near collapse.


Beluga feed on fish, crustaceans, and worms. The whale is related to the tusked “unicorn� whale known as the narwhal. The beluga is not related to the sturgeon of the same name, which has been heavily fished for its famous caviar. Did you know? Unlike most other whales, the beluga has a flexible neck that enables it to turn its head in all directions.

Fast Facts

Type: Mammal Diet: Carnivore Size: 13 to 20 ft (4 to 6.1 m) Weight: 2,000 to 3,000 pounds Group name: Pod Protection status: Threatened


Whale Behaviour

Whales have a streamlined shape and almost no hair as adults (it would cause drag while swimming). Killer whales and Shortfin Pilot whales are the fastest, swimming up to 30 miles per hour (48 kph).

Breaching Many whales are very acrobatic, even breaching (jumping) high out of the water and then slapping the water as they come back down. Sometimes they twirl around while breaching. Breaching may be purely for play or may be used to loosen skin parasites or have some social meaning.

Skyhopping This is another cetacean activity in which the whale pokes its head out of the water and turns around, perhaps to take a look around.


Lobtailing Some whales stick their tail out of the water into the air, swing it around, and then slap it on the water’s surface; this is called lobtailing. It makes a very loud sound. The meaning or purpose of lobtailing is unknown, but may be done as a warning to the rest of the pod of danger.

Logging Logging is when a whale lies still at the surface of the water, resting, with its tail hanging down. While floating motionless, part of the head, the dorsal fin or parts of the back are exposed at the surface.


e iv L s le a h W e Wher

Whales can be found inhabiting all of the worlds major oceans from the Arctic and Antarctic oceans to the tropical waters at and around the center of the equator. Depending on species and migration patterns some whales may be found particularly abundant in some locations while completely absent in others. Factors such as food supply, the whales overall size (which affects the climate the whale can comfortably survive in) and mating grounds may also affect the location of a particular species of whale. For example killer whales can be found in all of the major oceans but are more concerned with migrating to where their food supply goes than where they mate, therefore their prey

plays a large role in where the killer whale lives. Humpback whales on the other hand travel thousands of miles from the colder polar regions they inhibit to warmer tropical climates during migration periods to find a mate and bear offspring. During these trips humpback whales will completely forgo eating and focus primarily on traveling to their mating grounds. Some species of whale may inhibit a small region year-long and choose not to make long migration trips. The bowhead whale for example will spend the entire year traveling around in Arctic/sub Arctic waters and only make small trips from one location to the other.


Killer Whale

The killer whale can be seen traveling throughout the worlds major oceans, but they typically prefer cooler climates compared to the tropical climates found near the equator. As stated earlier the migration pattern of these whales is more often than not determined by their prey’s migration.

Gray Whale

Gray whales are often found swimming in the eastern and western north pacific ocean during feeding season and will migrate towards the Baja peninsula of mexico and the southern golf of california where they mate and bare off spring during their mating period.

Blue Whale

Blue whales can be found traveling all the major oceans. They can often be seen swimming in the colder regions during feeding season and will migrate towards tropical waters when mating.

Sperm Whale

Sperm whales can be found in all of the worlds major oceans. Female sperm whales and their young prefer to stay in near tropical waters all year-long while the males can be seen traveling back and forth from the colder climates to the warmer climates during mating periods.


Humpback Whale

hile humpback whales can be found traveling all over the world they prefer the cold waters in and around the Arctic and Antarctic oceans.

Minke Whale

There are two known species of minke whales currently in existence, the common or north Atlantic minke whale (which inhibits the north Atlantic waters) and the Antarctic or southern minke whale (which lives in the Antarctic region south of the equator). Due to differences in climate changes in both regions the two species of whale do not meet one another during mating periods because their mating seasons are different.

Beluga Whale

Beluga whales are generally found swimming in shallow coastal water in and around Arctic waters. Depending on the area and environment the whale is in some beluga whales will make seasonal migration trips while others will only travel within a small localized area.

Bowhead Whale

Unlike other species of whale bowhead whales are generally found traveling in Arctic/sub Arctic oceans year round and aren’t known for making long migration trips.


Why Whales Migrate 1. They migrate for mating and feeding purposes.

2. They migrate primarily to maintain their food supply. 3. They are wanderers and travel the world without any notable migration pattern. 4. They do not migrate and maintain a fixed distance from their home location all year round.



Whales