Whales!!
Whales are part of a group of large aquatic mammals that inhabit all oceans and certain fresh waters.
Whales have a fish-like body with horizontal tail fins, called flukes. These are used to propel the whale forward. Their skin is
smooth and glossy, and can be a variety of patterns and colors.
Underneath the skin there is a thick layer of fat, called blubber, which provides insulation and prevents the loss of body
fluids. The Blue Whale is the largest to have ever lived, and can grow up to 100 feet long and can weigh as much as a 150
tons.
There are nine families of living whale. These families are arranged into 2 major groups, the Baleen whales, and the Toothed
whales. The most noticeable difference between these 2 groups is that the Baleen whales lack teeth, while the toothed
whales have little cone-shaped teeth. Included among the toothed whales are a number of smaller species better known as
dolphins and porpoises. (see DOLPHINS; PORPOISES)
Baleen whales = Gray whale
Blue whale
Fin whale
Sei whale
Right whale
Humpback whale
Toothed whales = Beluga
Bottle-Nosed whale
Sperm whale
Killer whale
Narwhal
Whales have been hunted as a source of many useful products. Their bones, meat, and blubber yield valuable oil. The
blubber and meat are also used for food for both man and animal, and the bones may be made into bones and fertilizer.
Whales may obtain certain drugs including hormones, and the intestine of the sperm whale may yield a waxy substance called
ambergris, which is used in the manufacture of perfume.
Structure.
Like all mammals, whales have a four-chambered heart, are warm-blooded, and breathe air.
The young are born live and are nursed with milk produced by the mother's mammary glands. Unlike most mammals
however, whales have no hair on their bodies. They also differ from other mammals by their nostrils, which open on the top
of the head in a blowhole. The blowhole has a valve that closes automatically when the whale dives and opens when the
whale surfaces.
Senses.
Hearing is the whale's most acute sense, and all whales depend on hearing to detect danger and communicate. Many also use the sense of hearing in a system of guidance, called echolocation, which is similar to solar. Echolocation makes it possible for whales to swim through dark and turbid waters. Baleen whales have a poor sense of smell, and toothed whales lack it entirely. However, all whales have a fairly good vision, and their eyes are specialized for aquatic life. Greasy substances produced by the tear glands protect the eye from salt water.
Feeding Habits.
Toothed whales feed on relatively large animals, such as squid and fish, using their teeth to catch and hold the pray. They have a large throat and swallow their food hole, without chewing. Baleen whales also swallow their food whole, but they have a small throat and can only eat small animals. Their diet consists of small fish that gather in groups near the surface of the water, and small shrimp-like creatures collectively called krill. In feeding, the whale swims through a school of krill with it's mouth wide open, capturing large numbers of these tiny animals. The whale then closes it's mouth and forces the water out between the baleen plates. However, the krill cannot escape.
Swimming and Diving.
Whale's swim by making powerful up and down movements of the tail and flukes.
Some species, such as the sei whale, can swim up to 25 or more miles an hour. That's about 40 kilometers an hour.
But they usually cruise at much slower speeds. The right whale is the slowest and swims a 6 miles an hour. That's about 10
kilometers an hour.
Most whales swim near the surface of the water, but some dive to great depths and stay there for long periods. The
greatest-known depth, 3,720 feet, was reached by a sperm whale that got entangled in a undersea cable and drowned. The
longest under-stay recorded was made by a harpooned bottle-nosed whale that stayed submerged for 2 hours.Whales have
various adaptations for deep dives and for spending long periods underwater. Their lungs and adjoining air passages are
rigidly constructed, which prevents collapse under the pressure of great depths.
The Blow.
When a whale surfaces to breath. It usually exhales and inhales very quickly. The exhaled breath, which we can see, is called the blow. The blow contains tiny droplets of water and, possibly, of oil. The shape, height, and angle of the blow is typical for each species and can be used to identify a distant whale.
Migration.
Many whales migrate to cooler waters in the summer and to warmer waters in the winter. The cool summer grounds are
generally the feeding grounds, and the warm winter ones the breeding areas.
Whales may travel alone or in pairs, large or small groups.
Mating and Reproduction.
Some whales have no special mating species and breed throughout the year. Others have a definite mating season. The female bears only one offspring at a time. In it's lifetime a female may bear from 5 to 15 young. Whales may live from 20 to 40 years.
Whaling.
In the early days of whaling, hunters traveled long distances by ship. When a whale was sighted, the harpooners went out in
small boats which was often at the mercy of the whale.
By the 1600's, England and the Netherlands were the major whaling nations. America entered into whaling in the 1700's.
Toward the latter part of the 17th century, European whaling declined as a result of wars and a scarcity of whales. During
this time however, the American industry was growing rapidly, and by the mid1800's had become th most important whaling
nation in the world.
Regulations and laws have been in effect for centuries, but unfortunately the whaling regulations have many weaknesses and
as a result whales continue to be over-hunted. Can we save these magnificent species in time before they are extinct?
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