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Blue Whale

Page history last edited by Catherine Jacobs 2 yrs ago

By Catherine Jacobs

Introduction

The Blue Whale is the largest animal to have existed on earth- EVER. On average, whales grow to a length of about 90 feet and weigh about 145 tons. While the Blue Whale seems like a giant, frightening creature, it is actually very shy and is a filter feeder that feeds on small animals such as krill. Blue whales started to become endangered when the whaling industry turned to them for there valuable oil and meat.

Introduction
Classification
Characteristics of the Blue Whale
Bibliography

Classification

Kingdom: Animal
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Balaenidae
Genus: Balaenoptera
Species: Musculus

Characteristics of the Blue Whale

Habitat

Blue Whales in all oceans of the world, but are most common in the Southern Hemisphere, North Pacific, and North Atlantic.

They generally live at the surface of the ocean so that they can come up for air, and are most commonly seen in continental shelves and ice fronts. Blue Whales migrate often. They spend their winters in temperate and subtropical regions, and migrate to polar regions in the spring and summer.

Food Source/Food Chain

Although the Blue Whale may look incredibly scary, it's actually much more harmless than a shark. In fact, Blue Whales don't even have teeth! They are filter-feeders, and have what are called baleen plates instead. These plates are black in color and are made up of a protein called keratin, the same protein that makes up human fingernails. They overlap in a series of 260-400 on each side of the upper jaw. These plates help whales to feed on small, shrimp-like creatures called krill. To feed, whales' plates expand, allowing for large volumes of water and food to be taken in. As the mouth closes, water is expelled through the plates, trapping the food near the tongue to be swallowed. During the summer, whales may consume up to 4 tons, about 40 million krill, or more, each day!

Social Behaviors

Because whales are generally shy animals, they either live individually or in very small groups of 2 to 4. However, they have been seen swimming in groups of up to 60 off the coast of Califronia. The Blue Whale reaches sexual maturity between the ages of six to ten years, or around 74 ft for males and 79 ft for females. Breeding mostly occurs near the surface in warm waters during the winter to early spring time. Newborn whales, or calves, are about 25 ft long and weights about six to eight tons. After birth, the newborn swims to the surface within 10 seconds for its first breath. With the help of its mother, it will learn to swim within 30 minutes. Twins are extremely rare. The calve is nutrured by its mother's fat-laden milk, helping it to grow about 1.5 inches in length and gain about 200 lbs a day (about 8 lbs an hour).

Interesting Characteristics and Behaviors

Respiration

While you might guess that the whale is a fish, it is actually a mammal. This means that the Blue Whale has lungs. How does the whale breath under water if it has lungs? Well, the answer is simple. Whales are able to hold their breath for up to an hour! After going for a deep plunge (up to about 305 ft), the whale comes back to the surface to breath. It has two blowholes located near the top of the head. It will then spout about 5-12 times per minute. This blow of water is a single stream that can rise up to 50 ft above the surface of the water.

Vocalization

Surprisingly, whales are the loudest animals on earth! They make very loud, highly structured, repetitive low-frequency sounds that can be heard for hundreds of miles. The call reaches up to 188 decibles, which is even louded than a jet! These sounds are used for locating large masses of krill and also for communication with other Blue Whales, especially to attract mates.

Why This Animal is Endangered

The Blue Whale only has one sea predator- the Orca Whale. It is known to kill new born Orcas. If that is the case, then you may be wondering, "Why are Blue Whales endangered species?"

For many years, the Blue Whale was safe from local whalers because of their enormous size and great speed. Whalers were not able to chase them using their open boats and hand harpoons. The Blue Whale population was thriving with over 350,000 on the plant. However, in 1868, a Norwegian whaler named Sven Foyn invented the exploding harpoon gun. He also started to use steam and disel powered factory ships and catcher boats. He even came up with the idea to inflate dead whales with air so they wouldn't sink after they were shot. Because of the whales valuable meat and oil (a regular whale can yeild up to 120 barrels of oil), the whaling industry began to focus on whales after 1900. The killing peaked in 1931 when over 29,00 whales were killed in just ONE season. In 1966 the International Whaling Commission banned all hunting of blue whales, giving them worldwide protection. There are now an estimated 10,000-14,000 whales left in the world, and only in the last few years have there been signs that the population is increasing.