My Science School

               The Galapagos penguins are the only penguin species found north of the equator, and in the Galapagos. With an estimated population of less than 2000 individuals, the species is said to be endangered.

               Typically, Galapagos penguins have black-grey upper-parts and whitish under parts, with two black bands across the chest. Unlike cold water penguins, they have several adaptations that allow them to survive in warmer climates. The birds mainly feed on krill and small crustaceans.

               As we saw, the population of Galapagos penguins is shrinking. The obvious threats to their survival are pollution caused by chemicals and oil in waters, climate change, and accidental capture by fishing nets etc.

               In addition, the birds are also vulnerable to attacks and diseases from introduced species like cats, dogs and rats. However, the dangers posed by El Nino events are the worst.

Picture credit: google

          Not many of us find vultures attractive or friendly. Rather, they look a little threatening. But these birds, we should know, play a very important role in the food chain- they feed on animal carcasses, and prevent the spread of deadly bacteria and fungus into the ground and water.

          Sadly, the population of the vulture species is falling at an alarming rate. One of the birds that is facing the risk of extinction is the Indian vulture. It is a wild bird, native to India, Pakistan, and Nepal.

           Like others, Indian vultures too, feed on dead bodies. They can be spotted in cities, towns, and villages near cultivated and open areas, and in woodlands too.

          As per the IUCN Red List, Indian vultures are critically endangered, with a population of around 30,000. A serious decline in their numbers happened in the 1990s, when they lost around 95 per cent of the individuals.

          This unnatural death toll was caused by the presence of diclofenac, a drug used to treat livestock.

Picture credit: google

            The blue-throated macaw is a rare parrot that can be spotted only in the northern parts of Bolivia in South America. They mostly inhabit palm groves and savannas in the northern parts of the country. With their turquoise blue and yellow plumage, blue cheeks, and long elegant tails, the macaws are unusually attractive. However, we just don’t get to see them at all!

            It is said that until the 1970s, blue-throated macaws mostly remained unknown. But as soon as they became popular, the illegal trade of these birds began. The fact that the species is rare made them all the more expensive and sought-after in the international pet market.

            The trade became so intense that at one point, there weren’t any wild specimen. Luckily, by 1992, the birds were rediscovered. However, the wild population of blue-throated macaws still remains fragmented, and as low as 400!

Picture credit: google

            The Madagascar heron is a rare and large grey heron that is endemic to the island of Madagascar. Also known as the Hum-blot’s heron, they are birds that have an endangered existence due to hunting and loss of habitat.

            In appearance, these herons are distinctive, with dull grey plumage, and long pointed beaks. Mostly they are seen standing solitary and motionless in shallow waters, a habitat they are perfectly adapted for.

            As said earlier, Madagascar herons are rare birds that are now facing the threat of extinction. The main reason for this is the conversion of wetland habitats in the country for rice cultivation. As a result, the birds are forced out of their habitats to an unsafe existence. In addition, there are other problems too, like the stealing of heron eggs, and the capture of nestlings by local people for food.

            As of now, the population of the heron is just between 1000 and 1500.

Picture credit: google

          The red-crowned crane is one of the rarest cranes in the world that is found in Japan, China and the Korean Peninsula. They are known to be very attractive birds with mostly white feathers, and a black tail. Their name comes from the red feathers on top of their head.

          The birds are mostly spotted in wetlands, rivers, mudflats, grassy tidal flats, and paddy fields. With a population of less than 3000, the red-crowned cranes have become an endangered species. Habitat destruction is the primary threat they face.

          Yet another is the threat of poisoning. Reports suggest that the birds are often killed by eating pesticide-treated grains.

          In addition to these grave issues, there are also instances of fire and poaching that contribute to the decline of red-headed crane population.

          There are many efforts made by wildlife organisations towards conserving the species, like increasing the scope of wetland restoration and controlling invasive species.

Picture credit: google

            The Lear’s macaw is a large parrot endemic to Northeastern part of Bahia in Brazil. It is named after Edward Lear, a famous British artist cum poet who painted macaws, and wrote rhymes about them.

            For a long time, the macaw remained elusive in the wild. It was in 1978 that it was accepted as a distinct species by naturalist Helmut Sick.

            Typically, Lear’s macaws are very noisy and social. Their diet comprises of fruits, seeds, and nuts. The overall grayish-blue plumage, long wings and tail, and a distinct vibrant yellowish-orange colour that encircle the eyes-altogether make the bird beautiful.

            The most serious threat faced by the macaws is illegal trade. It is said that collectors of these birds pay high prices in the international pet market to own them.

            Another threat is the reduction in the number of licuri palms which the birds mostly feed on. Together, these have all contributed to the decline of Lear’s macaws.

Picture credit: google

            The Malagasy pond heron is a migratory bird, seen primarily in the outer islands of the Seychelles, Madagascar, and countries on the east coast of Africa such as Kenya, Tanzania, and Uganda. It is also called a Madagascar pond heron, or Madagascar squacco heron. The species in general has long crest, red legs, blue beak with a red tip and blue bare skin around the eyes. Strangely, the plumage of the birds becomes streaked with brown, and the crown turns completely brown when the species is not breeding.

            The habitats of the herons can be seen in freshwater wetlands, typically with nearby tree-cover.

            In 2007, the IUCN Red List classified the Madagascar pond heron as an endangered species. It was the result of a population decline caused mainly by over-harvesting of eggs, and the clearing of habitats. In addition to these, there is also a competition for food and habitat with other herons too. This also caused the decline in their number.

Picture credit: google

            The Vietnamese, or the Vo Quy’s pheasant, is a rare pheasant that is endemic to Central Vietnam. The range of this bird concentrates around the Ke Go Nature Reserve in Ha Tinh province.

            The pheasant was discovered in 1964, and described in the year that followed, by the Vietnamese zoologist Vo Quy. Hence, it was named after him.

            Typically, the male pheasant is more attractive than the female. It has a shiny black plumage with dark blue tones, and blue-edged feathers on the body. The female is rather unattractive with plain, greyish-brown plumage. It is said that they mostly feed on grain, seeds, plants and insects.

            According to the IUCN Red List, Vietnamese pheasants are an endangered species. The destruction of coastal lowlands and commercial logging are among the main factors that contribute to the population fall.

            Besides, a considerable number of these birds are hunted for trade and meat.

Picture credit: google

          A legend says the coffee plant first grew in Kaffa, a province in south Ethiopia, where it was discovered by a goatherd called Kaldi about the year 850. Kaldi’s goats were reported to have skipped and pranced in a strange manner after feeding on an evergreen plant. The goatherd, so the story goes, tried some of the berries himself and excitedly dashed to the nearest town to tell of his find, which was called coffee after the name of the province.

          Another theory is that the word coffee is probably derived from the Arabic qahwah. Certainly coffee was introduced info Europe from Arabia during the 16th and 17th Centuries. The first license to sell coffee in the United States was issued to Dorothy Jones of Boston in 1670. The coffee houses of this time became famous meeting places for discussion.

          As the drinking of coffee be­came more popular, its production spread to Java, Haiti, Dutch Guiana, Brazil, Cuba, Jamaica, Puerto Rico, Costa Rica, Vene­zuela, Mexico, Colombia, the Hawaiian Islands and, in this century, Africa.

Picture credit: google

               People stop growing when their bones do, and that is usually between 15 and 25 years of age.

               Bones are made up of living tissue, composed of special cells which secrete round themselves material rich in calcium salts and as hard as marble. The formation of bone (ossification) is a complex process which usually begins in cartilage (gristle).

               In a child the bone begins to form in the middle of the cartilage and spreads towards both ends, turning it all to bone with the exception of the tips. From these points the bone grows in length and so does the child. When the growing period is over the tips of the bones close by joining the main shaft of the bone.

              Bones vary greatly in shape and size. Long ones act as levers. Flat ones are centers for muscle action. But each has a cavity containing bone marrow. Around this the bony substance is spongy in texture, becoming hard nearer the surface where the calcium is densest. On the surface of the bone is a special layer of fibrous tissue (the periosteum) which is rich in bone-building cells.

          Loam soil is half way between clay and sandy soils. It is the best soil for horticultural and agricultural use, containing enough clay and humus for the retention of water and for the provision of food for plants. It also has sufficient sand to allow the passage of air and the drainage of water, which prevents water logging, and enough lime to prevent acidity.

         River basins are often covered with a powdery, yellowish-grey loam called loess. This loam has been brought downstream by the river and is derived from glacial deposits of very fine silty, unconsolidated material. Some of the best farming land in the Rhine and Danube basins is composed of this soil. Other loess deposits have no connection with glacial action and are accumulation of fine material picked up by the wind in the world’s arid regions. When water is introduced into these loess areas by means of irrigation they make unusually fertile soil.

        There are loess deposits in the plains of south Russia, the Argentine pampas and China, and in lowa and Illinois in the United States. These are among the richest agricultural regions in the world.

Picture credit: google

The manchineel tree is dangerous because its sap and fruit contain poison. Its other name is Hippomane, which comes from the Greek and means “causing horses to run mad”

      The tree is a member of the Euphorbiaceous family and grows in tropical America, producing a crop of acrid, bitter apple-like fruits which drop spontaneously and carpet the ground beneath it. The sap is white and highly caustic, so that a drop on the skin produces a burning sensation and raises a blister. It used to be believed by many that to sleep beneath the tree meant certain death. But the great 18th century naturalist Nicolas von jacquin “reposed under it for hours at a time without inconvenience”.

     The wood has often been used for furniture as it is beautifully patterened in brown and white. Before felling the tree by hand, workman light a fire round the trunk, so that the sap thickness and does not run down the handles of their axes.

               

                Mudskippers are small tropical fish of the eastern Atlantic, the Indian Ocean and the western Pacific from Australia to Japan. They live in estuaries with mudbanks and also in mangrove swamps. Their eyes protrude from their heads and can be moved independently of each other. When the mud is exposed by the ebbing of the tide the mudskippers come out of the water and hunt for crustaceans and other small invertebrates. They crawl and hop about rapidly with the help of their powerful muscular pectoral fins which they use as forelegs. Their gill openings are small and they can live on land for hours at a time, providing the air is humid.

Picture credit: google

Laurel and holly trees have developed special kinds of leaves to seal the water inside them during the winter months.

    Both trees are evergreen .Instead of dropping all their leaves in Autumn, They shed old ones and grow new ones throughout the year. In winter the soil is too cold for the trees to draw water from it through their roots. Normal leaves would continue to transpire and to give off moisture until the trees died of drought. But the special leaves of the holly and laurel hold the water .their waxy surface and leathery texture make certain that the water is contained safely within the green tissues.

    Some of the holly leaves have a further modification. On the lower branches which are within reach of browsing animals, each leaf has a series of sharp point along its edge. The higher leaves have only a single point.

            The green colour in grass-and in most other plants-comes from chloroplast within the cells, each of which contains four different colours or pigments. These are: chlorophyll a, which is the strongest and is blue-green; chlorophyll b. which is yellow green; xanthophylls, which are yellow; and carotene, which is orange and gives carrots their bright colour.

            Grass goes from light green in early spring to dark green and brown in summer and' autumn because the amount of each pig­ment changes, like the paint on a palette, to mix new colours.