Whales
by Staff EditorLike its cousin the dolphin and humans, the whale is a warm-blooded mammal. As the largest animal in the world, it can grow to a length of over 30 meters and weigh in excess of 180 tons. At the height of a nine-story building, the Blue Whale is the largest in the whale family.
Whales belong to a group of mammals called cetaceans. This group includes whales, dolphins and porpoises and while there are many types of whales, there are just two main species:
1. Baleen Whales:
Baleen Whales are the largest of the whales and are characterized by the baleen, a sieve-like structure in the upper jaw that they use to filter plankton from the water.
2. Toothed Whales:
Toothed Whales have teeth and generally feed off of fish and squid. Through the process of echolocation (whale songs), they are able to sense their way through their surrounding environment.
Whales are the descendants of the ancient land-dwelling Artiodactyl mammal. It is believed that they entered the water about 50 million years ago. Though they have evolved in the water, whales have many similarities to humans and other land-dwelling mammals. First, whales breathe air into lungs as opposed to the gills of most other sea creatures. Second, they give birth to one baby (called a calf) at a time. Gestation in whales usually lasts about 12 months, after which the calf is born tail first to avoid the risk of drowning, After a calf is born, it is breast-fed and can tale between seven and 10 years to reach maturity and break away from its mother. A third linking trait between whales and humans is the existence of hair, though minimal compared to other mammals.
A whale’s breathing is not instinctual that is, they must decide when they want to breathe. Whales acquire oxygen through blowholes located on the tops of their heads. The Baleen Whale has two blowholes, whereas the Toothed Whale has just one. To inhale, a whale must exit the water for a brief period. They then dive back into the water to exhale, at which point a spout that varies in shape and size from whale to whale becomes visible.
Whales are able to remain submerged for long periods of time the Sperm Whale, for example, can remain underwater for up to two hours on a single breath – but they still cannot afford to fall asleep for extended periods of time for fear of suffocation. In order to remedy this, only one hemisphere of a whale’s brain falls asleep at one time, allowing it to be sufficiently awake to fetch air when it needs it. Even in fragments, whales still manage to sleep about eight hours a day.
Even though it is classified as a mammal, a whale’s body more resembles that of a fish in its streamlined, aerodynamic shape and its paddle-shaped flippers. At the end of its tail are fins, which move vertically to propel the whale through water and its genital organs retreat into the body when it is swimming to increase its speed and avoid drag.
Beneath the surface layer of the skin, a whale has a layer of fat called blubber that serves as insulation and provides an energy reservoir and most whales have a fused neck vertebrae, which gives them stability in the water.
It is generally accepted that whales are intelligent creatures, with some even suggesting that they are smarter than humans. In the accepted definition of intelligence, that is, “the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience,” whales seem to be able to do all of the above at a level on par with humans, if not superior. Many proponents of whale intelligence use their capacity for language as an example.
It has been well documented that whales communicate with each other via a song-like system of communication used to attract food, mates or to warn other whales in the pod of impending danger. The sounds they make have been known to generate upwards of 20, 000 watts of sound at 163 decibels and can be heard for miles. Though their communication system may contain some of the elements of traditional language, this is still under research.
WHALE ACTIVITIES:
1. BREACHING: Breaching is when a whale jumps high and slaps the water as it comes back down and re-enters.
2. SPYHOPPING: Spyhopping sees the whale poking its head out of the water and looking around.
3. LOBTAILING: When lobtailing, the whale will stick its tail out of the water into the air, swing it around and slap it onto the water’s surface, making a loud noise. Its meaning is unknown but lobtailing may be performed to indicate impending danger to other whales.
4. LOGGING: Logging is when a whale lies still at the surface of the water resting with the tail hanging down. Part of the head and back are exposed at the surface.
Whales migrate each year from cold water feeding grounds to warm water breeding grounds and usually eat anything from tiny plankton to large fish. Whales do not mate with a single partner for life. In fact, during mating season, a female can have many breeding partners.
Whaling has posed a significant threat to the global whale population over the last century or so, rendering many whale species extinct or close to the brink. In the 19th and 20th centuries, whales were hunted for oil, meat and baleen, among other things. The International Whaling Commission issued a worldwide ban on whaling in 1986, save for a few countries and communities who were still permitted to hunt whales. These countries are: Norway, Iceland and Japan as well as the aboriginal communities of Siberia, Alaska and northern Canada.
Though there are two main species of whales, there are numerous types of whales within those species. A few examples are:
- Beluga Whale
- Blue Whale
- Bowhead Whale
- Gray Whale
- Humpback Whale
- Killer Whale
- Minke Whale
- Narwhal
- Orca
- Right Whale
- Sperm Whale
