Why do pelicans have a sack in their beaks?
Pelicans use the sack for catching fish. Interestingly, different species of pelicans use different hunting methods. Some hunt in a semicircular formation and drive the fish from deep to shallow water so that the fish cannot dive down. The pelicans then immerse their long beaks in the water and scoop the fish in their sacks. The baby pelicans feed by taking the fish from the sack of the parents. Another species, the brown pelicans, does a vertical nosedive in the water from a height of 10-20 m and fills its sack with fishes from the deep water.
The growth rate of the frog’s population is the same in ponds near the coast or in the garden at home. Tadpoles develop from fertilized gelatinous eggs. These are larvae of frogs, which have gills and move forward with the help of a tail. Gradually, they go through a transformation to become a frog. The process is called metamorphosis. The tadpoles develop front and back legs, cartilages become bones, the tail retracts, lungs develop, and the gills regress. Now, it can move on land as well as water. Such a metamorphosis takes place in other animals too, for instance in butterflies or beetles.
The highest mountain peak of the world is Mount Everest with a height of 8850 m. Animal do not live on ice-covered mountain peaks and in the areas where even mountaineers can manage only with an oxygen flask. Animals that have adapted themselves to the rough conditions live below a height of 6000 m - goat-like animals such as Himalayan tahrs, ibexes and cashmere goats, the pikas with their small ears and the endangered snow leopard. Yaks are also found here, which the local people use for carrying loads.
Groundhogs live in widely branched burrows below the ground, but come out on the surface every day to collect grasses, seeds, and insects. A few species live in colonies in high mountains. They divide work amongst them—when a few animals have gone out in search of food, the others are on guard. If they sense danger from approaching enemies, they emit a shrill whistle to warn the others. In the summer, the animals must feed enough to put on a thick layer of fat so that they can survive the 6-9 months long winter sleep.
Both animals have adapted to their mountain habitat. The chamois live in the upper mountain forests and fields and climb higher only in summers. The ibexes, on the other hand, live in icy and rocky regions and look for food in mountain meadows. They never go down to the forest. Species of ibexes are found in the mountain regions of Europe and Asia, on the Arabian Peninsula, and in north-eastern Africa. Chamois, on the other hand, are found only in the mountains of Europe: in the Alps, Carpathian Mountains, and Pyrenees as well as in Caucasus Mountains.
Most of the forest ants build hills at sunny forest edges from needles, twigs, and moss. The well-organized huge colonies of ants are called ‘hills’. Several hundred queens live with their ‘community’ in these hills. The ants divide the work among themselves. While the queens lay eggs, the soldier ants must provide protection for the eggs and the worker ants get food for the larvae. In the month of June, the winged male and female ants hatch. The males die after the nuptial flight. The impregnated young queens look for a new ground or return to the old one to lay eggs.
It is easy to distinguish between the large fallow deer, the red deer, and the small deer. The male red deer has royal antlers with several ends, while a roebuck (male roe deer) has only one small horn. The small deer, red deer, and fallow deer belong to the biological family of the stag, which also includes the moose and the reindeers. The small deer, weighing about 15 kg, are the most frequently seen today. They live in the area between forest and arable land. The female doe can give birth to two to three fawns, which bear three long series of white spots on the back. Red deer weigh up to 150 kg and prefer to live in forest clearings. The hinds (female red deer) can give birth to a maximum of one calf in a year.
A forest is a large area of land covered with trees. Forests can be classified into many types, some of which are the mixed temperate forests with both coniferous and deciduous trees, the temperate forests, the subtropical forests, the tropical forests, and the equatorial rainforests. The trees that make up the forest create a special environment which, in turn, affects the kinds of animals and plants that can exist in the forest. Large and small animals such as the stags, deer, wild boars, foxes, badgers, marten, and squirrels live in the forests.
Many birds such as starlings, cranes, and swallows migrate to the south in autumn because they do not find enough food in winter. It is not good to feed the birds because it may disturb their regular habits of finding food for themselves. Their destination and the migratory path is the same every year. For years, scientists puzzled over the birds’ ability to take exactly the same path every year but now it is assumed that birds possess a ‘magnetic sense of direction’ and orient themselves to the magnetic field of the Earth, using the position of the sun during the day, and the stars at night.
Moles spend a large part of their lives in a self-dug burrow system below the ground. The animals push the loose earth that is a result of digging to the earth’s surface after every 50-100 cm. The result is a typical molehill, about 20 cm high. Sometimes we also come across huge hills with air holes all around. Below these molehills the moles make a nest in which they give birth to their young ones.