|
There has long been an almost mystical connection between people and whales.
This is only natural because of all the creatures in the sea, none are closer
relatives to us than these warm-blooded mammals. Experts put forward the
theory that 60 million years ago, ancestors of modern whales were four-legged,
wolf-sized animals living on the shores of estuaries and lagoons, where an
abundance of fish and shrimp enticed them to try wading. Evolution started
reshaping them. Over 10 to 15 million years, their bodies grew, forelegs shrank
into flippers and hind legs disappeared. To propel themselves through water,
whales grew tapered tails ending in horizontal, paddle-like flukes. The nose in
most species moved to the top of the head and became separated from the mouth;
whales could therefore feed without filling their lungs with seawater and
breathe without sticking their heads up. The inside of the whales were
restructured too. Therefore, they could feed and communicate entirely underwater
while being utterly helpless on land. If stranded on a beach, they can hardly
breathe.
Despite their size, these giants move at a good speed. A blue whale swimming
at 15 knots generates 1,000 horsepower. Humpback whales can heave their 40-ton
bodies completely out of the water. Superb streamlining is one reason for a
whale's swiftness. The skin is another reason. It is loose and lubricated, with
ridges induced by rapid swimming, all of which help the leviathans slip through
the seas with little significant drag.
A whale can eat up to 9,000 pounds of food a day. The type of whale known as
toothed (like Moby Dick) lives on fish and squid. The baleen strains its food.
After engulfing enough water to fill a dining room, the baleen whale spits it
out through a sieve of bony plates dangling from its upper jaw. The world's
biggest creature feeds itself almost entirely on shrimp-like krill smaller than
a person's thumb.
The humpback whales have devised the most ingenious feeding technique -
bubble netting. Rapidly circling under a school of fish, it forces bursts of air
through its blowholes, creating a rising spiral of bubbles that corrals the
fish. Seconds later, the whale bursts up through the centre, gulping several
hundreds of fish at once.
Even though they live in the same element, whales do not behave like fish. In
fact, many people think whales represent the best of human behavior. Many whales
exhibit strong family ties. The young remain with their parents for up to
fifteen years or more. Like reindeer and other nomadic land mammals, such
migrating species as humpbacks and grey whales live in herds, or pods, and
travel seasonally between feeding and breeding grounds.
In times of stress, whales look after one another. During migration, a group
travels at the speed of the slowest baby. When a member is wounded or sick, the
others refuse to abandon it. They may cradle it between them or support it on
their backs so it can breathe. Such care giving behavior has often led to their
downfall. A whole loyal group could easily be picked off by whalers.
A whale's urge for companionship can be irresistible. If two surface within a
thousand feet, they often sidle up to each other during their few minutes at the
surface. Maternal instincts are also highly developed. When a calf is born
underwater, the mother must get it to the surface before it drowns. Often
another whale will help. The mother nudges it gently until the baby is confident
with its swimming - usually after about 30 minutes. If the calf is stillborn,
she may support it on her back until it literally rots away. Like all mammals,
whale babies feed on mother's milk. But whales have to devise a system for
delivering milk to a baby that cannot stay submerged for long. They squirt the
milk directly into the baby's mouth - 130 gallons a day in blue whales. The milk
is more than 30 percent fat, over ten percent protein and the babies grow
extremely fast. A blue whale calf lengthens by two inches a day and gains an
average of seven pounds per hour. Mother whales have been seen fondling their
babies. Their flippers are used like hands to clasp, coax and discipline.
Whales are generally gentle, unflappable and have tremendous self-control.
They do not harm human beings unless they are provoked. Although misunderstood
by humans at times, whales have no trouble communicating with their own kind.
Their snores, groans and clicks are used to identify the sexes and keep pods in
contact. A family spread out over several square miles almost certainly knows
where everyone is. Whales have loud voice. A blue whale can bellow as loud as an
elephant. The best talkers are humpbacks. These frisky, free spirits sing
hauntingly beautiful songs for up to 22 hours at a time; seemingly just for the
joy of it, though probably to attract a mate. All the whales in one area sing
the same song, but they cannot stop tinkering with it. So every few years their
tune completely changes. In 1985, the Soviets used sound to rescue some 3,000
belugas. They had cleared an escape path, but the confused animals, frightened
by the noise of engines and propellers, refused to leave. Then, the ship began
piping music through loudspeakers - military, folk, jazz and rock. It was when
they heard the strain of Beethoven that the whales began to follow, swimming
through the narrow channel to freedom. |
