Bionics: Birds have superb flying skills. Of course, modern airplanes are far superior to birds in many performances, but they are dwarfed in energy saving and dexterity. For example, a bird flies over the ocean for more than 4,000 kilometers and loses 0.06 kilograms; Small hummingbirds can not only take off and land vertically, but also take an upright posture when sucking nectar, hanging freely in the air and moving forward and backward, which is extremely flexible. The research and utilization of these special functions will further improve the performance of the aircraft.
For example, wild ducks can fly leisurely at a half-height of 9500 meters, but it is already difficult for people to breathe when they climb 4500 meters. It is of great significance for human beings to live normally and prolong their lives in an environment with insufficient oxygen supply to study why birds' cerebral vessels are still unblocked under the condition of thin air.
Pigeons have made great contributions to bionics. There is a small and sensitive special structure on its leg to feel the earthquake. According to its principle, people copied a new seismograph to make earthquake prediction more accurate. Its eyes have special recognition ability, because there are six kinds of ganglion cells with specific functions on its retina: leaf brightness detector, common edge detector, convex edge detector, direction detector, vertical edge detector and horizontal detector. The electronic model of pigeon eyes made by people imitating the cell structure on its retina is not as complex and perfect as it is, but it has broad prospects in installing on warning radar and applying it to computer processing related data.
Shanghai water accounts for 97% of the total water on the earth. At present, the artificial desalination device of seawater has huge equipment, complex structure and high energy consumption. However, seabirds such as seagulls and albatrosses can discharge the salt from the sea water they drink through a salt gland near their eyes. Once the simulation of this function is completed, the prospect of human utilization of the ocean will be broader.
In addition, people are developing Hawkeye system missile according to the structure of Hawkeye, which can automatically find and identify the target and track the attack when flying over the target.
Economic value of birds: The economic value of birds is very extensive. Its uses can be divided into six types.
Poultry. Like chickens, ducks, geese, pigeons, quails, etc., they mainly provide human beings with the source of protein. Poultry is domesticated by pheasants. For example, the ancestors of domestic chickens are original chickens, domestic ducks are mallard ducks, and domestic geese are geese. Therefore, wild birds can be used to continuously improve the varieties of poultry, because pheasants have the characteristics of large size, fast growth and strong disease resistance, and are a very rich gene pool. Domesticating pheasants can expand the variety of poultry. If people start raising swans, bustards, black-bone chickens and brown-eared pheasants now, they may become new varieties of poultry in the future. Therefore, we should pay attention to protecting pheasants.
Hunting birds. Like wild ducks and chickens, their meat is edible, and their feathers can be used as feather fans, headdresses, down jackets and duvets. As long as the relationship between protection and utilization is properly handled, they can become a renewable and inexhaustible important resource.
Manure birds. The habitat where birds are concentrated and the place where they migrate are often the main producing areas of phosphate fertilizer. For example, the dung left by boobies in Xisha Islands is several meters thick.
Medicinal birds. We are familiar with bird's nest and black-bone chicken, as well as white chicken and clove chicken.
Ornamental birds. Like thrush, lark, parrot, mandarin duck, peacock, etc.
Livestock. Like cormorants, sparrows and goshawks, they are good assistants for people to carry out fishing and hunting activities.
Scientific value of birds: In fact, human aviation technology does not surpass birds in all aspects. Birds' wings can make quite complicated movements. In particular, one fan and one stroke can continuously generate an aerodynamic force, which can be decomposed into lift and propulsion, making the flight comfortable. Birds can also temporarily put away their wings and slide while flying to reduce physical exertion. People envy many advantages of flapping-wing flight, and are stepping up their efforts to imitate and develop flapping-wing "flapping-wing aircraft".
In addition, the unique physiological structure and function of birds provide bionic scientific research topics for the innovation of mechanical systems, instruments and equipment, building structures and technological processes. In particular, birds' sensitive and accurate functions of orientation, navigation, detection, control and adjustment, information processing and biomechanics have led people into new scientific fields. For example, the "pigeon-eye radar system" made by using information bionics.
Ecological value of birds: an owl can kill 1000 voles in one summer, which is equivalent to protecting a ton of grain. A thousand purple-winged starlings that live in groups can kill 20 tons of locusts during the breeding period. A swallow can eat 500,000 to/kloc-0.0 million mosquitoes, flies and aphids in a summer. A woodpecker can peck 500,000 pests parasitic in bark a year. Many birds, such as grey magpie and cuckoo, are insect-eaters. It is difficult to estimate the role played by various birds in nature in defending human economic interests and maintaining human health. In the past, people thought that pesticides could replace everything, so they applied all kinds of chemical pesticides indiscriminately, which polluted the environment. Thus, people realize the great role of biological control, especially birds, in the natural ecosystem.
Wild birds are the source of poultry. The importance of poultry in people's lives need not be described. At present, there are more than 60 kinds of domestic chickens in the world, which provide us with high-quality meat, eggs and down feathers. Today's poultry are all screened, domesticated and cultivated from wild birds by our ancestors, and people are still trying to explore the domestication of wild birds? Except that the familiar domestic chickens were domesticated from Gallus gallus, domestic ducks were domesticated from Anas Platyrhynchos, Anas Poecilorhyncha and Cairna moschata. Domestic geese are domesticated from Anser cygnoides, Anser anser and Alopochen aegrptiacus, domestic pigeons are domesticated from Columba livia, and cormorants (osprey) are domesticated from wild cormorants (Phalacrocorax carbo). Such as quail (Coturnix coturnix), ring-necked pheasant (Phasianus colchicus) and ostrich (Struthio camelus). In recent years, China has successfully domesticated some rare birds, such as Crossopilon mantchuricum, in semi-wild state, which provides us with such a problem: China is one of the countries with the richest wild birds such as chickens in the world, how to better protect them, study them and domesticate more valuable species. China was one of the first countries to domesticate poultry. For example, Western Europe has always considered that it was the first domesticated domestic chicken in India in 2000 BC. According to the research of Chinese ornithologists, the domestication history of chickens in China is at least not later than that in India. Recently, the bones of domestic chickens were found in the early Neolithic cultural site in Cishan, Wu 'an County, Hebei Province, and the history of raising domestic chickens in China dates back to more than 7,000 years ago. What our ancestors could do more than 7,000 years ago will surely be done more and better today when science is so prosperous. Wild birds provide a lot of meat, eggs, down and manure for human beings.
Wild birds are tender, nutritious and delicious, and they are much less likely to be polluted by industries such as cities than poultry, so they become a good choice for people to eat, and the price is much more expensive than poultry. China is rich in hunting birds, many of which enjoy high reputation. For example, the hazel chicken, a specialty of Daxing 'anling and Changbai Mountain, was once a tribute of dynasties and was called "Feilong". Birds provide people with raw materials such as down and decorative feathers every year, as well as various light industrial products, toys and arts and crafts processed from them, which are even more numerous. Their value is sometimes difficult to estimate. As far as the decorative feathers of American Egret (Casmerodius albus) are concerned, it was popular in western Europe to put some beautiful feathers on women's hats at the beginning of this century, especially the decorative feathers of American Egret are the most precious. The 1902 was sold in the London market alone, with a weight of more than 1 300 kg, which was more expensive than gold at that time.
Bird droppings contain a lot of nitrogen and phosphorus compounds and are high-quality organic fertilizers. Seabirds, such as cormorants, albatrosses, gulls, etc., gathered in coastal areas and islands are the main providers of bird droppings. Every year, there are 300,000 metric tons of bird droppings provided by South America and Africa, among which Peru has the highest output, and the bird droppings deposited on the islands there are 55 meters thick. Since the19th century, factories have been built for mineral development, but up to now, the accumulated bird droppings are still 8 centimeters thick. Many islands in Xisha Islands in China are almost completely covered with bird droppings, which is a resource with great development potential.
The value of wild birds in medicine and ornamental is also well known. The medical uses of dozens of birds are recorded in Compendium of Materia Medica. Of course, we must take a cautious attitude in medicine.
The most important and easily overlooked thing about birds is their indirect benefits to people. It is estimated that there are about 100 billion birds. They are distributed in various environments, and play a very important role in eliminating pests and animals and maintaining the ecological balance (stability) of nature. It has been praised by people since ancient times for eliminating pests and restraining insect disasters. According to "Miscellaneous Stories in Xiyang", "In Kaiyuan, locusts ate grasses, and there were thousands of white birds and tens of thousands of small white birds, all of which ate their insects". 1848 When Mormons opened up Utah in the United States, they were hit by floods, and then thousands of crickets came, and the crops were swept away wherever they passed; Just when the victims were at a loss, thousands of Larus californicus flew in, which soon wiped out the crickets. Today, in the square of Salt Lake City, Utah, there is still a $40,000 monument with two golden seagulls.
Some people calculate that a swallow can eat 500,000 to 1 million flies, mosquitoes and aphids in summer. One thousand purple-winged starlings (strunus vulgarus) can exterminate 22 tons of locusts during the brooding period. The investigation of Xinjiang pink starling (Strunus roseus) shows that they can reduce the number of locusts per square meter from 33 to less than one during the breeding period. The protection of birds on forests and urban gardens is also obvious. Many pests under the bark and in fruits that cannot be killed by pesticides can be pecked by birds one by one. The most notable example in this respect is the woodpecker. Some people have studied two kinds of American woodpeckers and found that they can kill 52% of overwintering larvae in orchards and 64-82% of overwintering larvae of corn borer in farmland. Many birds have made an important contribution to controlling the dangerous enemy Dendrolimus punctatus in coniferous forests. Someone once found 173 Dendrolimus punctatus, 12 scarabs and 49 gypsy moth larvae in the stomach of a cuckoo (Cuculus canorus). Beneficial birds were attracted to Dailing Forest Farm in Heilongjiang Province to control larch pests, which reduced the overwintering Dendrolimus punctatus from 10. 1 to an average of 1.3 per plant in the control area. The vast majority of birds in nature feed on insects or feed their chicks with insects, and their role in eliminating pests is very considerable.
Birds of prey (eagles and owls) mainly feed on rodents such as mice, which is very helpful for controlling pests in agriculture and forestry. Someone found the bodies of 1,348 mice in the stomachs of 360 vultures. Owls are birds of prey that move at night, just to kill rats that move at night. Someone studied19,00 pieces of owl food scraps and found that there were 46, 179 mammals, almost all of which were rodents. Some people calculate that an owl can kill mice in one summer, which is equivalent to protecting a ton of grain. According to the analysis of food scraps of wintering long-eared owl in Wuchang, Hubei, 70.3% of them are small mammals, mainly Apodemus agrarius. Apodemus agrarius is an important pest in China's farmland, and it is also the disseminator of dangerous hemorrhagic fever in many areas. Owls have made remarkable achievements in this regard. We should also see that many birds, especially vultures, owls and other raptors, seagulls, crows, etc., have the habit of eating carrion. They have made special contributions to eliminating sick animals and rotting corpses and eliminating organic pollution to the environment, and are called "scavengers of nature".
Many birds are the disseminators of plant pollen and seeds, especially in the tropics. According to statistics, there are more than 80 species of birds that feed exclusively on nectar in Australia, among which there are hummingbirds, sunbirds, peckers, embroidered birds, snipes and parrots found in southern China. They fly between flowers and play a role in spreading pollen when pecking nectar. Birds that feed on plant seeds, especially thrush, thrush and thrush, which are common in the north. Jay, Jay and Star Crow, etc., have contributed to the spread of many tree species and are experts in "afforestation" in nature. For example, the star crow likes to eat oak seeds, and it has the habit of storing acorns in autumn. It often collects hundreds of acorns and stores them in different corners in the distance, but it is often forgotten. These scattered acorns are one of the reasons for the expansion of oak forests. It has been proved that some hard-shelled plant seeds germinate more easily after passing through the digestive tract of birds; Coupled with the attached bird droppings, even the fertilizer is provided, which is of course easier to survive.
It should be pointed out that when people evaluate the benefits of birds, they usually focus on the direct benefits and obvious indirect benefits. In fact, from the perspective of the whole ecosystem, because of the variety, large number and wide distribution of birds, they are at different nutritional levels in the ecological cone, and the relationship between the food chains is extremely complicated, which occupies an important position in energy flow. Even the seemingly harmless or even harmful species, if hunted excessively, will destroy the natural balance of the ecosystem through the food chain, which will lead to serious consequences.
However, the relationship between birds and people is complicated, and it varies with time, place and specific conditions. For example, birds that specialize in eliminating agricultural and forestry pests are of course beneficial birds, but they also eat beneficial insects. Moreover, strictly speaking, it is not enough to know how many pests it eats a day to determine the benefits brought by birds. It is still necessary to find out whether the number of pests in nature is really suppressed by the feeding of these birds. Some birds can kill a large number of pests in spring and summer, but they spoil crops in spring sowing and autumn harvest, and feed on weed seeds in the field in winter. Therefore, "benefit" and "harm" are relative, and there is no absolute beneficial bird or absolute harmful bird. Despite these complex problems, after in-depth research by ornithologists, it is agreed that all the birds that exist today, with a few exceptions, are beneficial or not very obvious, and the beneficial birds account for the vast majority.