The environment of the hare in the forest
Fact fitness of organisms For a very long time, the church used the conditions of their habitation as a supposedly "scientific" proof of the existence of divine power. Only Darwin's theory finally refuted the myth of "primordial, God-given" fitness. In the light of Darwin's theory, fitness turned out to be a necessary and natural consequence of natural selection.
As an example of working out fitness through the development of protective coloration in very many animals can serve. About 100 years ago, the light gray moth, the birch moth, was very widespread in England. During the day, she sits on the trunks of a birch - and the light color of her folded wings masks the insect well. But in connection with the development of the industry, the soot of numerous factory pipes gradually began to settle on white-trunk birches growing in industrial areas. The bark has acquired a darker color. Under these conditions, the once masking coloration of moths has ceased to be useful. Due to the change in conditions, the direction of selection also changed. If earlier (on white trunks) birds ate primarily darker butterflies, and lighter ones survived, now (on dark trunks), on the contrary, the darkest butterflies survived, and the lightest became victims of birds. This process continued from generation to generation during last 100 years. And now the zoologists of England have based two different races of the moth: in the countryside the old light still lives, and in the industrial areas - a new very dark race. So for a relatively sooty period of natural selection, one of the adaptations has developed - the protective coloration of these butterflies.
Very interesting how examples of facial expressions and disguises... With mimicry, individuals of some defenseless species with their shape, color, behavior resemble another, which has active means of defense. An example is defenseless flies that "imitate" such armed insects as bumblebees or wasps. Disguise is achieved by the resemblance of animals to bodies of inanimate nature. So, for example, the caterpillars of some insects in a stationary state are very similar to a twig of a tree; a callima butterfly with folded wings looks remarkably like a dry leaf of a tree.
A wide variety of adaptations to cross-pollination and the spread of fruits and seeds are widespread among plants. In animals, various kinds of instincts play an important role as adaptations (caring for offspring, instincts associated with obtaining food, complex instincts of social insects such as bees, ants, etc.). There are many similar examples in zoology and botany.
One of the main evidence natural origin devices- their relative nature. Any adaptation is useful only in relation to the conditions in which it historically arose. Take the example discussed above: the light color of the moth is useful in rural areas, the dark color in industrial areas. But even for the given conditions in which this or that adaptation was developed, its usefulness is also relative. First, organisms protected by various adaptations become victims of their enemies, albeit in a smaller number than their less protected counterparts. Secondly, constantly fluctuating environmental conditions often create situations in which the adaptation ceases to "work". So, for example, for a white hare, an adaptation in the form of a change in the color of the hairline is very useful: in summer this hare is dark, and in winter it is white. But one year the snow fell very late, and the hare had long since turned white; under these conditions, its white color instead of patronizing will be unmasking. And at such a time many hares die. A very important evidence of the relative nature of fitness is rudiments, that is, organs that have lost their usefulness in new conditions, but have not yet completely disappeared.
Snowy hare: nutrition, reproduction, adaptation to life
Hare inhabits various biotopes - from the arctic tundra and northern coniferous forests (taiga) to the mountains, where it settles above the forest border. In many places, the white hare can only hide in a few shelters, so it has to endure freezing wind and rain all year round. The blue hare is perfectly adapted to life in cold regions, lying in the north or high in the mountains. It can even withstand temperatures of -40 C. Hare feeds mainly on grass, low shrubs and various perennial grasses. He remains in his shelter until dusk and only then goes in search of food.
Animals living in the southern regions of the tundra, with the arrival of winter, move to the edge of the taiga, to the boundless coniferous forests. Here they find more reliable protection from the cold and wind. White hares that spend the winter in the open tundra can find shelter only behind rocks and under low bushes. In Scandinavia, the white hare stays in the food-rich taiga regions all year round.
Hare breeding
During the mating season, males become very aggressive towards each other. Almost the entire period they attack each other and fight for females. Mating takes place in March, but in the tundra it is postponed to a later date and occurs at the end of May. Hares are born 50 days after mating. The female feeds the rabbits with milk once a day. The entire brood keeps close to the mother, without scattering. Sometimes the hare tries to ward off the enemy from the kids, pretending to be wounded.
Adapting a hare to life
The white hare, like many other herbivorous animals, becomes the prey of predatory animals. In winter, when everything is covered with white snow, the hare's fur becomes completely white, so the animal is practically invisible on the snow and ice. In the spring, the color of the white hare's coat changes again (depending on the temperature) to dark, blackish-brown or brownish-red. These changes are governed by temperature and daylight hours. These animals simply need to adapt and blend in with their surroundings.
In places where there is no snow, the white hare does not change its dark color to white. For example, the white hares that live in northern England, the coat remains variegated in winter. In some subspecies of the white hare that live in the Arctic, the coat remains white in summer. Good eyesight, smell and speed are also important for the white hare. The hare's eyes are located high enough on the sides of the head, which gives it a very wide field of view. The hare simultaneously examines large area space. Having noticed the enemy, he first freezes in place in the hope that he will not notice him. Seeing that he was found, he flees. In the snow, the hare digs tunnels, hiding from predators and frost.
Winter wool: very thick, especially on the auricles. White paint provides camouflage in snow-covered areas. Summer wool: the coat in summer is not so thick and is colored brown-gray or reddish-brown. Ears: the white hare has short ears to prevent excessive heat loss. The black-tailed hare, which lives in the desert regions of California, has very long ears, thanks to which good cooling of the body is provided. Paws: the foot is covered with thick hair. Wool protects the hare from the cold and helps it to keep more confidently on snow and ice.
Nowadays, the white hare is not threatened with extinction. However, its habitat in cold climates has specific features, so the intensive use of the Arctic and the pollution of these regions gives cause for concern.
Snowy hare: nutrition, reproduction, adaptation to life
Hare inhabits various biotopes - from the arctic tundra and northern coniferous forests (taiga) to the mountains, where it settles above the forest border. In many places, the white hare can only hide in a few shelters, so it has to endure freezing wind and rain all year round. The blue hare is perfectly adapted to life in cold regions, lying in the north or high in the mountains. It can even withstand temperatures of -40 C. Hare feeds mainly on grass, low shrubs and various perennial grasses. He remains in his shelter until dusk and only then goes in search of food.
Animals living in the southern regions of the tundra, with the arrival of winter, move to the edge of the taiga, to the boundless coniferous forests. Here they find better protection from cold and wind. White hares that spend the winter in the open tundra can find shelter only behind rocks and under low bushes. In Scandinavia, the white hare stays in the food-rich taiga regions all year round.
Hare breeding
During the mating season, males become very aggressive towards each other. Almost the entire period they attack each other and fight for females. Mating takes place in March, but in the tundra it is postponed to a later date and occurs at the end of May. Hares are born 50 days after mating. The female feeds the rabbits with milk once a day. The entire brood keeps close to the mother, without scattering. Sometimes the hare tries to ward off the enemy from the kids, pretending to be wounded.
Adapting a hare to life
The white hare, like many other herbivorous animals, becomes the prey of predatory animals. In winter, when everything is covered with white snow, the hare's fur becomes completely white, so the animal is practically invisible on the snow and ice. In the spring, the color of the white hare's coat changes again (depending on the temperature) to dark, blackish-brown or brownish-red. These changes are governed by temperature and daylight hours. These animals simply need to adapt and blend in with their surroundings.
In places where there is no snow, the white hare does not change its dark color to white. For example, the white hares that live in northern England, the coat remains variegated in winter. In some subspecies of the white hare that live in the Arctic, the coat remains white in summer. Good eyesight, smell and speed are also important for the white hare. The hare's eyes are located high enough on the sides of the head, which provides a very wide field of view. The hare simultaneously examines a large area of space. Having noticed the enemy, he first freezes in place in the hope that he will not notice him. Seeing that he was found, he flees. In the snow, the hare digs tunnels, hiding from predators and frost.
Winter wool: very thick, especially on the auricles. White paint provides camouflage in snow-covered areas. Summer wool: the coat in summer is not so thick and is colored brown-gray or reddish-brown. Ears: the white hare has short ears to prevent excessive heat loss. The black-tailed hare, which lives in the desert regions of California, has very long ears, which provide good cooling to the body. Paws: the foot is covered with thick hair. Wool protects the hare from the cold and helps it to keep more confidently on snow and ice.
Nowadays, the white hare is not threatened with extinction. However, its habitat in cold climates has specific features, so the intensive use of the Arctic and the pollution of these regions gives cause for concern.
