A complete collection of facts about 12 interesting animals

1. Do cats lick their fur because they love cleanliness?

Many people think that cats are clean animals and that they lick their fur to take a bath, but this is not true. There is a special substance in the fur of cats. After being exposed to sunlight, it changes and becomes nutritious vitamins. Cats lick their fur to eat vitamins, not to take a bath.

2. Why can't geckos close their eyes?

Geckos like to live in the courtyards of human houses and often catch pests for humans. If you pay attention, you will find that geckos' eyes are always open, even when they sleep. Although geckos have large eyes, they have no upper eyelids, so they can never close.

3. How do the young red kangaroos enter the pouch?

The young red kangaroos crawl into their mother's pouch by themselves. However, this is not a smooth journey, but a difficult one. Although the hind limbs of the newborn cub are very weak, the forelimbs have already grown claws. With the help of nerves and muscles, it starts from the female's cloaca, follows the mother's tail, and crawls like a worm into the pouch supported by the pouch in the abdomen. At this time, its eyes are not open yet, and it is not easy to find the mother's pouch. If it is not careful, it will fall off the mother's tail and die. After going through untold hardships, the cub finally entered the pouch. It looked for nipples everywhere, grabbed one (the female has 4 nipples in total), held it in its mouth, and hung its body on it to continue to grow. So, the young of the red kangaroo grows out of the nipple.

In the female's pouch, the young will only stick its head out when it grows to about 160 days; after 200 days, it will start to leave the pouch and go out to move around. However, it is very timid. Once there is a slight disturbance, it will quickly get into the pouch to avoid risks and come out to move around after the wind and sea are calm. When the female is resting, the naughty young will get into the pouch for a while to enjoy the warmth of the mother, and then crawl out of the pouch to play, looking very busy. After leaving the pouch, the young will take 3 to 4 years to grow into an adult red kangaroo.

4. Why do zebras have stripes?

The stripes on zebras are beautiful and elegant. They are one of the main marks for mutual identification between the same species. More importantly, they form a protective color to adapt to the environment. In open grasslands and deserts, these black, brown and white stripes reflect light differently under the sun or the moon, blurring or dispersing the outline of their body shape. Looking around, it is difficult to distinguish them from the surrounding environment. This protective effect of not easily exposing the target is very beneficial to the animal itself. Recent studies have also found that the stripes on zebras can distract and weaken the attention of mosquitoes and flies on the grassland, which is a means to prevent them from biting. This protective color is gradually formed through long-term adaptation to the environment and natural selection, because in history, there have been some zebras with unclear stripes. Because of their obvious targets, they are easily exposed to natural enemies, hunted, and finally extinct. They have been gradually eliminated in the long process of biological evolution. Only those species with distinct and conspicuous stripes can survive to this day.

5. Why is the "high blood pressure" of giraffes not a disease?

When a giraffe raises its neck high, its head is about 2.5 meters above the heart. It is not easy to press the blood in the heart to more than 2 meters. When it lowers its head to drink water, its head is more than 2 meters below the heart. How can it bear the blood flowing down to the brain? Generally speaking, large animals have slow heartbeats and small animals have fast heartbeats. The heart of a giraffe weighs more than 10 kilograms, and the heart wall is more than 7 centimeters thick, which is very strong and powerful. When it is still, its heart beats up to 100 times per minute, 2-3 times faster than a horse, and it can pump up to 60 liters of blood per minute, while a horse can only pump 20-30 liters. The heart pumps up to 300 mm of mercury, and the blood pressure of the carotid artery under the brain is maintained at 200 mm of mercury, so the giraffe can be called the animal with the highest blood pressure in the world. Because it must have such a high blood pressure to pump the blood from the heart to the head 4-5 meters high. If it were another animal, it would have fainted with such high blood pressure.

Some people have suggested that the high blood pressure of the giraffe has finally solved the problem of blood supply to the head, but how can its brain withstand such high blood pressure? It turns out that the morphology of the giraffe's arteries and veins has been specialized. The carotid artery is divided into many small blood vessel plexuses at the base of the brain, forming a complex reticular spongy body; and the jugular vein is particularly large, with a diameter of more than 2 cm, and has a series of valves that can withstand high blood pressure. Therefore, when the giraffe raises its head, the jugular vein is deflated, and the blood pressure in the jugular vein is 200 mm Hg. The high blood pressure rushes to the corpus cavernosum and automatically lowers the blood pressure, so that the blood pressure entering the brain remains normal and does not damage the brain. When the giraffe lowers its head, the valve of the jugular vein closes, so that the blood is stored in the wide jugular vein. The venous blood will not return to the brain and the flow back to the heart will be reduced. At this time, its carotid artery blood pressure drops to 175 mm Hg. When the blood rushes into the corpus cavernosum, many small blood vessels expand and reduce the pressure, so that the brain blood pressure remains normal.

Therefore, high blood pressure is an adaptation to the giraffe's long neck raising and lowering activities, and it is not pathological. The carotid artery corpus cavernosum at the base of its brain and the valve of the jugular vein are effective guarantees for adapting to high blood pressure.

6. Why are penguins called "penguins"?

Penguins are the largest family of birds in Antarctica. Although penguins have bird heads and beaks, they cannot fly. They stagger on land and are naive, but once in the water, they are like a lively fish, swimming in the water at a speed of 18 kilometers per hour. Therefore, people give this flightless bird a special title - the ship of the ocean. The Chinese name of the penguin is associated with its posture. The original meaning of "企" is "standing on the heels". Penguins stand like people on land. When they stand on the seashore or in the snow, they always look like they are looking up and looking forward to something, so they are named "penguins".

7. Cute red panda

Red pandas are also called little pandas. Because of their adorable appearance, they are naturally dressed like animals in cartoons. In Sichuan, people affectionately call them "Shan Men De Er" or "Shan Che Wa Er" based on their special habits, while people in Yunnan call them "Golden Dog" based on their body shape and beautiful fur color. They are fat and look like bears and domestic cats, but they are much smaller than bears and larger than domestic cats, so they are named red pandas.

Red pandas are rare and special animals distributed in high mountains and subalpine areas such as the Himalayas and Hengduan Mountains. They are found in southern Shaanxi, southeastern Qinghai, southern Gansu, Sichuan, Yunnan, Tibet and other places in my country.

When people talk about red pandas, they naturally think of giant pandas. Not only do they have similar names, but they also have short and strong skulls, strong cheekbones, feed on fibrous plants such as bamboo, have very similar teeth, feet suitable for climbing, hairy palms, coarse body hair, and similar internal organs. Many common characteristics make it easy for them to be considered as closely related animals. In fact, the red panda and the giant panda are far apart in kinship, and they do not belong to the same family in terms of classification. The giant panda belongs to the giant panda family, while the red panda belongs to the raccoon family.

Red pandas mainly live in high mountain jungles such as mixed forests and bamboo forests at an altitude of 1,600 to 3,800 meters. At night, they live in nests built in dead tree holes or rock holes near streams and mountain springs. They like to move in small groups of 4 to 5. Red pandas like to drink water and often move around by the stream. When drinking, they lick the water gently with their tongues, as if they are carefully tasting the sweet spring water, but they are very restrained. Because of the thick fur on the soles of their feet, they are very suitable for walking on the slippery ground or rocks under the dense forest. When walking, their front feet bend inward, and their gait appears to be staggering, similar to the walking posture of bears. Usually, they are relatively docile and rarely make sounds, but when they are angry, they will make a "hissing" sound like a cat's meow, and they will spit. When they are angry, they will make short and low grunts. Red pandas are very agile and good at climbing trees. They rest and sleep on trees covered with a layer of light reddish-brown moss most of the day. When they encounter windy and sunny weather, they also like to squat on rocks to bask in the sun, which seems very leisurely and comfortable, so local people also call it "mountain gate squat". When resting, the chest and abdomen are usually close to the branches, and the four legs are naturally drooping. From time to time, they use their front paws to wipe their white face, or use their tongues to lick the fine hair on their bodies. When sleeping, they use their fluffy and hairy tails to cover their heads or use them as pillows. Sometimes they also hang their feet high and lie on branches.

Red pandas usually eat by sitting down and holding food with their front paws. The main food is the leaves and bamboo shoots of cold arrow bamboo and large arrow bamboo, which account for more than 90% of the total food. Occasionally, they also eat roots, stems, tender shoots, tender leaves, wild fruits of other plants, as well as insects, bird eggs, small birds, small animals, honey, etc. They especially like to eat sweet food. Foraging activities are mostly in the early morning and evening. After the climax of these two foraging activities, they will take a long rest of about 4 hours. In addition, during foraging activities, they also take short breaks frequently, and each rest time is often less than 2 hours. This ensures that there is enough energy to carefully select bamboo leaves, solving the defects of low nutrition and limited digestion capacity.

For carnivores, bamboo is a food with low nutritional value because of the high content of indigestible cellulose and lignin in bamboo. Therefore, the countermeasure adopted by red pandas is to eat bamboo leaves almost all year round, except for eating some bamboo shoots in spring and summer and a small amount of wild fruits in autumn, because bamboo leaves contain more digestible crude protein, hemicellulose, soluble carbohydrates and other cell components, and the content of indigestible plant cellulose and lignin is lower than that of bamboo stalks and branches. Although the tissue of bamboo shoots is tender and the content of indigestible components is low, the water content is too high and the protein contained is unstable. Therefore, bamboo leaves should be the part with the highest nutritional value among all parts of bamboo. When looking for food, it often uses dead trees as passages, just like building a shelf, to make up for the deficiency of short body, so as to eat bamboo leaves on high stalks and branches. This method of taking small amounts of food carefully and chewing them slowly can promote the maximum absorption of nutrients and greatly improve the utilization rate of resources.

8. The privilege of the king

In the northernmost part of the earth, the northernmost coastal areas of Eurasia and North America, most islands in the Arctic Ocean and Greenland, there lives a carnivorous bear: the polar bear. An adult polar bear can be up to 2.7 meters long, more than 1.3 meters tall at the shoulder, and weighs about 600 kilograms. Throughout the year, its fur is pure white only in winter, and it is light yellow-white in other seasons. In the white snow, it is really tall and mighty, and has a noble demeanor! The so-called privilege is the special skill of its fur to absorb ultraviolet rays. The fur of polar bears is like a hollow tube, and there is no pigment in the hair. The reason why it looks white is that the inner surface of the capillary tube is relatively rough, just like transparent snowflakes appear white when they fall on the ground. It is these capillary tubes that allow ultraviolet rays to pass through the core, just like unobstructed ultraviolet tubes. Polar bears use this fur "tube" to absorb almost all the sunlight, including ultraviolet rays, that shines on them to increase their body temperature.

9. What do butterflies do on rainy days?

Butterflies only do one thing on rainy days - hide from the rain. For a large butterfly weighing only 500 mg, a storm is not a trivial matter: if it is hit by a drop of rain weighing 70 mg, it is like us humans being hit by two small bowling balls.

Heavy rain can also hinder the movement of butterflies. To prepare for flight, these aerial stunt pilots must let the sun shine directly on their wings, because only in this way can they quickly warm their wing muscles, and rainy and cloudy clouds block the solar radiation they need to take off. Therefore, when the sky is overcast and dark, butterflies will look for shelter in their habitat. And when the sun smiles again, they will return to the blue sky within a few minutes. Let us also be like butterflies: first find a place to hide from the rain, and once the sun smiles again, immediately throw ourselves into the arms of nature and enjoy the fun of life.

10. Speed ​​and Power

The cheetah, a hunting animal on land, can be said to be the running champion of the wildlife kingdom. This ferocious cat lives in the tropical grasslands of Africa. The cheetah's abdomen is extremely flexible, like a spring. The cheetah's tail plays an important role in maintaining body balance. And its claws are always stretched out, like the spikes on the soles of running shoes, when it runs,Increased the power of digging the ground. So far, no land animal has been able to break the highest record set by the cheetah.

Cheetahs have a set of methods to make themselves reach the highest speed in running. They arch their backs and pull in their abdomens, so that their hind paws can reach forward as much as possible before landing, so as to extend the span of each step. Then, in order to make their front paws reach forward as much as possible before landing, the cheetah does the opposite, pulling in their backs and arching their abdomens.

In this way, the cheetah is like a bug, arching and stretching. It runs at a speed of 100 kilometers per hour, and there is also a record of 110 kilometers per hour. At this speed, a cheetah can make an excellent 100-meter athlete start the race at 65 meters, and the one who reaches the finish line first is still the cheetah. Because the highest speed of a human is only about 36 kilometers per hour. The best result of a 100-meter athlete is about nine seconds, and the athlete almost does not breathe within this 100 meters. This is because the oxygen inhaled can only take effect on the human body after about 20 seconds. If the distance exceeds 20 seconds, of course, breathing is needed to replenish the required oxygen. Therefore, different distances require different ways of exercise.

It is not yet known whether cheetahs hold their breath when running, but cheetahs are definitely sprinters in the 400-meter race. Before rushing towards the prey, it approaches the prey slowly and gently, first "walking" and then trotting. Large cats are not good at trotting. So the cheetah quickly changes to a galloping state. The speed is getting faster and faster. The cheetah can catch the gazelle in one go with its agility. It can jump up to 7 meters at a time and can jump 3.5 times per second on average.

11. Flying mammals - bats

Although bats can fly freely in the sky, they are not birds, but belong to the class of mammals, the order Chiroptera, which is the second largest mammal group after the order Rodentia, and is divided into the suborder Megachiroptera and the suborder Microchiroptera. There are at least 1,116 species of chiropterans in the world. In recent years, new species of bats have been reported all over the world (including my country). With the application of molecular biology in bat classification, the classification system of bats has also undergone new changes. At present, the suborder Megachiroptera only includes 1 family, 42 genera and 186 species of Pteropus; the suborder Microchiroptera includes 17 families, 160 genera and 930 species. Some species have adapted to the living environment of humans and live in buildings, almost all over the world. There are 127 species of bats recorded in China.

12. Living Fossil - Chinese Sturgeon English name: Chinese Sturgeon Scientific name: Acipensr sinensis

The Chinese sturgeon is the largest fish species in the Yangtze River and is known as the "Yangtze River Fish King". It is also a very ancient fish species that has lived on Earth for 150 million years. Such an ancient fish species is rare, so it is also called a "living fossil". Due to many reasons such as overfishing and environmental damage, the number of Chinese sturgeons has been greatly reduced and is in danger of extinction. It is listed as an endangered species by the World Conservation Union (IUCN). It is a first-class protected wild animal in my country and can be called a "giant panda in the water".

As early as the Zhou Dynasty more than 1,000 years BC, the Chinese sturgeon was called the king tuna. It has a pointed snout, a small mouth without teeth, and an oval cylindrical body. There are four tentacles in front of the mouth, which are used to search for invertebrates, small fish and other food at the bottom of the water. The Chinese sturgeon often travels between rivers and seas, and is a typical sea and river migratory fish. Its spawning grounds are mainly distributed in the lower reaches of the Jinsha River below the Niulan River and the upper reaches of the Yangtze River above Chongqing.

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