Category Biology

How is Nightingale distinct from other birds?

               In the kingdom of birds, nightingale enjoys a unique status for its ability to sing. This quality of nightingale has made it quite popular with poets and no bird has been written of so much by the poets as the nightingale. Aristophanes, the great Greek poet wrote about it in the 4th century B.C. and Keats in the 19th century.

               According to the poets, the nightingale sings only at night  and in almost any season of the year. But this goes against the facts as the bird sings both in the day as well as in the night. Poets had a wrong perception because they could hear it only in the night and not in the day. The reason for this being that the song of nightingale is not audible in the day as it is being overshadowed by the chirping of other birds but it is distinctly heard in the silence of the night. Again, since nightingale is a migratory bird hence its voice is generally not heard throughout the year at a particular place. From season to season, it migrates to different places. 

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How do plants and animals defend themselves?

                    Almost every plant and animal in the world has enemies that threaten its existence. So to protect itself every living being has developed some defence mechanism. Sensing the danger some organisms hide, others run, while others just fly away. 

                 Some organisms can even hide without moving. They use ‘camouflage colouring’. That means that their skin colour blends in with the matching colour of the surrounding area so well that the enemies cannot see them. Chameleon has the capacity of changing its body colours. If it is on a green leaf, it turns green; if on a brown twig, it turns brown. Some rabbits change colour with the season. The snowshoe hare is brown in summer and white in winter. The white fur camouflages the rabbit in the snow. Another phenomenon called counter-shading is a common type of camouflage among the fishes. The underside of their body is of lighter shade than the top. This helps the fish to blend in with many shadows it might make. Some other animals have a remarkable ability to take the form and colour of some other object around them. Camouflage also helps some animals catch their food. Since they can blend in with their surroundings, their victims can’t spot them immediately, and thus get caught.

                    Then there are other animals such as antelope who can run very fast. Others may dodge back and forth, like a rabbit. Birds can escape most predators by flying away. 

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Which animals are extinct now?

               The study of the fossils has revealed that hundreds of species of animals and plants have come and gone since the creation of earth. To begin with, these species became extinct as a result of natural causes. The animals and plants that disappeared were those that were unable to adapt fast enough to the changing conditions of the earth or were unable to compete with their rivals for the available food supplies. However, there are other instances, such as the case of dinosaurs, in which the reason of their extinction is still not very clear. The animals which became extinct millions of years ago were never seen by man. Also there are some others that were alive only a few hundred years ago and man himself has been responsible for killing them and causing their extinction. Do you know which animals became extinct during the last few hundred years? 

             

 

                   There was a bird called dodo which became extinct by the end of 17th century. This bird lived on the small island of Mauritius in the Indian Ocean and had no proper wings to fly. For this reason people called them dodos which means ‘simpleton’ or ‘stupid’. It was hunted down by the Dutch sailors who landed in the island in 17th century. Dodo meat was good to eat and hence carried away in ships by the Dutch. Dogs and rats started eating dodo eggs and chicks. As a result all dodos vanished by the middle of 17th century. The same story marked the extinction of another bird called the Great Auk. This penguin-like bird lived on the islands north of Scotland as recently as the mid-19th century. Egg collectors and hunters drove it to extinction by 1844. 

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Which animal spends its life upside down?

               There is a family of mammals called ‘sloth’ found in tropical South America, the members of which spend most of their lives in upside down position. They move about the tree tops in very slow motion usually at night. They use the hooked claws of both their toes and fingers to move upside down and spend most of their lives in this peculiar position. The sloths can even go to sleep in this position. In sleep, their muscles become fixed and would not relax until the animal wakens and purposely does so. The sloths eat, mate and even give birth to their young in this position.

               There are two interesting characteristics related to this strange habit of sloths. The first is its ability to turn its head almost right round to compensate for its reverse position. The second relates to its hair that lies in the opposite direction to that of most of the other animals. The sloth’s hair runs from its belly round to its back, and this ensures that heavy tropical showers run straight off.

               The sloth hardly has any tail. Its nose is blunt and the peglike teeth are well-developed. The animal is hardly visible in trees because green algae cover the animal’s hair, providing camouflage. It feeds on leaves, buds and fresh twigs of trees.

               There are two main species of sloths. The unau or two-toed sloth which has two toes on the front and the ai, or three-toed sloth which has three toes on the front feet. In prehistoric times there were huge giant sloths that were about 6 metres (20 ft.) tall.

How did different plants get their names?

          Ever since the evolution of languages different plants and trees have been given names to distinguish one variety from the other. The nomenclature is essential for general use, for a gardener’s catalogue and for botanists. The source of their names is often very interesting and hence worth-knowing.

          Some names have simply been borrowed from other languages, while some others take the name of the places of their origin. Some plants have been named according to their shapes and colours while still others owe their names to some unique features of the plants. Some may have come after the names of their discoverers. Over the time even the names have undergone changes. The origin of names of some important plants and trees are discussed below. 

          The pine tree got its name from the Latin word pinus which means ‘a point’. The spruce tree should really be called the Prussia Tree because it was long thought to be a native of Prussia. The name gradually got corrupted to ‘spruce’.

          A butter cup is a flower which has the shape of a cup and the colour of butter. Lady’s mantle was the name given when ladies wore collars that were pleated and with serrated edges like the leaves of the plant. Honeysuckle has flowers rich in nectar and is, therefore, popular with bees collecting substance for making honey.

          The magnolia has been named after Pierre Magnol of France who was a professor of Botany. The cypress is called so because it was first brought from the island of Cyprus. In Madagascar, there is a tree called, ‘The Travellers Tree’. It has large, fan-shaped leaves that catch the rain water and the passing travellers sometimes quench their thirst with this water.

          The barber plant has been named so because the natives of Orient used to rub its leaves on their faces to check the beard from growing. The names dandelion comes from the French dent de lion because the leaves of this plant resemble the teeth of a lion. Thyme comes from the Latin word Thymus which means to sacrifice and the Romans used to burn this plant on their altars. 

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Who is called the king of fishes?

               Just as lion is called the king of beasts, the same way shark can be called the   king of fishes. It is the fastest and the most dangerous fish in the sea. It is also the largest of all fishes, ranging from one foot to over 50 feet in size. Another reason for calling it the king is that it belongs to one of the oldest groups of creatures alive in the world today. Some fossils of sharks are believed to be around 250,000,000 years old.

               A shark is a saltwater fish that belongs to the class Chondrichthyes. Its skeleton is made up of cartilage rather than bones. Its skin is covered with many small scales which are like sandpaper. There are about 400 species of sharks in the world. The dog-fish shark grows up to around 3 ft. in length. It feeds on small fish and invertebrates. The whale shark, the largest of all fish, can reach about 50 feet in length. It is the least dangerous. These sharks have many razor-sharp teeth. The great white shark, the greediest monster, swallows its prey whole. The remains of big animals, such as seals, dolphins and smaller sharks have been found in its stomach.

               A shark will eat almost anything found in the sea from the tiniest sort of sea creatures to other sharks, turtles, seals or dolphins. They have been known to swim up rivers and attack crocodiles, horses and elephants which might have waded into the water. They are also found to attack people swimming in the sea. When in pursuit of their prey, they can move very fast. They follow the ships to feed on the waste food thrown overboard from the kitchens of the ships. Some sharks live and hunt alone, while others prefer to roam the seas in packs. Most of the sea beaches in Australia and South Africa are protected from sharks by iron-nets and electric barriers, for the safety of the swimmers.

               Sharks are caught in large number every year. Their meat is very nutritious and cheap, and can be quite delicious if properly cooked. Their skin is used for binding books and covering boxes, and for making bags and shoes.

               The most beautiful shark is the mako shark. It is snow white underneath and brilliant blue on the top. It is very fast and ferocious and a strong fighter when caught alive.