What if the trees are full of crows when winter comes?

Noise disturbs people, excrement falls from the sky, pedestrians and vehicles are hard to prevent, and cleaners have a headache.

Our reporter Wang Wei reported that since winter, people have always seen crows sleeping on the high branches on both sides of Chang 'an Avenue at night. There are crows and feces everywhere, which makes urbanites feel a little overwhelmed.

Reader: The crow phenomenon must be eradicated.

A few days ago, a reader specially sent an email about crows. He said that in the area from the Ministry of Foreign Trade and Economic Cooperation on the south side of East Chang 'an Avenue to Dongdan Sports Center, hundreds of crows gather in the trees here every night, making noise and releasing a lot of excrement, which not only makes pedestrians sick, but also gives cleaners a headache.

He believes that Chang 'an Street is "the first street in China", the Ministry of Foreign Trade and Economic Cooperation and Beijing Hospital are important foreign-related and medical departments, and their environmental conditions are directly related to the image of the capital. Therefore, "crow pollution" must be curbed! He thinks we can learn from Singapore's method and shoot some crows with air guns to control their population growth.

Expert: The quantity has not increased, so it should not be sold.

Zhao Xinru, a bird expert at Beijing Normal University, told reporters that crows in Beijing mainly include crows with big mouths, crows with small mouths, crows from Western jackdaw in the west and crows with sudden noses. They go to the suburbs for food during the day and fly back to the city for the night because of the urban heat island effect. The situation in Beijing is different from that in Japan and Singapore. Crows only gather in winter. In March and May, some crows will migrate without putting too much pressure on the city.

Guo Geng, an expert on wildlife protection, said that the number of crows in Beijing has not increased significantly. In the past, Beijing was mostly dirt roads, and the feces of crows fell directly into the soil and were decomposed into nutrients. Now that the city has developed, roads are paved everywhere in Shi Zhuan, and the excrement of crows naturally stands out. Crows are "scavengers" in cities. Rats, pests and carrion are all their food. The increase of crows is the performance of improving environmental quality. People can find ways to control them, but they cannot shoot them.

Take effective measures to control the crowded population.

In many international metropolises, crows and pigeons in the square have become a problem. Beautiful bronze and marble statues are covered with pigeon droppings and crow droppings, which has caused great damage to urban sculptures. The London government had to add birth control pills to the bird food it sold. Similarly, biologists in Barcelona, Spain, have also come up with the bioengineering of "treating birds with birds" to control the breeding speed of urban pigeons. Japan, Singapore and other countries have also used shooting and cutting off food sources to reduce the number of crows. It is understood that this situation of crows is a thorny problem in almost all big cities.

Some experts pointed out that in order to avoid the troubles brought by crows to cities, appropriate measures can be taken to control them, such as: considering changing the distance between trees and houses to reduce the places where crows can live; Strengthen garbage disposal and add protective nets in garbage landfills. , reduce food sources.

It is understood that with the enhancement of people's awareness of environmental protection, more and more people begin to care for birds. In some cities, due to the lack of natural enemies, there are more and more birds, which has caused environmental pressure to cities. How to solve this problem scientifically needs the constant research and efforts of ornithologists.

enclose herewith

Russia launches "Defending the Kremlin" Falcon Guardian vs Rogue Crow

As we all know, the Russian Kremlin has always been famous for its onion-like gold-plated dome. Recently, however, crowds of crows flew to Jinding to pick Jin Yezi, which made this exquisite and magnificent building restless for a while. According to the Australian "Times" reported on the 22nd, Moscow authorities had to invite Falcon, the crow's natural enemy, as the "patron saint" of the Kremlin.

The battle against crows has been defeated repeatedly.

It is reported that the Kremlin is the palace of the Russian czar. It is located in the center of Moscow, covering an area of 28 hectares. It has a history of at least 800 years and is now Putin's presidential residence. However, for a long time, the Kremlin suffered from crows. These annoying birds croak all day, which makes people upset. What's more disgusting is that they often pee from the air. Crows are harmful to flowers and plants. When tulips and other exotic flowers sprout, the mob will rush in and you will bite them like a lawn mower. During the period of the former Soviet Union, the crow-driving movement began vigorously. At first, people's method of driving crows away was "humane", just letting crows take sleeping pills, but it was completely ineffective.

Later, people used shotguns to shoot, but because the Kremlin is located in downtown Moscow, it is inevitable that chickens will fly and dogs will jump every time the gunshots ring. Once, a member of the Politburo went to work in the Kremlin and witnessed the "bloody scene" of shooting crows. He nearly fainted with fear. Since then, shooting crows has had to be abandoned. In order to deal with crows, a group of experts from the former Soviet Union also went to Western Europe to learn from them. However, the experience of western Europe is not successful.

Five falcons guard the peace of Gong Ke.

In this decades-long war between man and crow, crows obviously once gained the upper hand, and their arrogance became more and more fierce. Recently, flocks of crows not only swaggered into the Kremlin to steal the leaves of rare trees, but even parachuted into Jinding, taking away precious pieces of Jin Yezi in broad daylight. Seeing that this ancient building was about to be destroyed, the heartbroken Kremlin managers finally moved in "reinforcements"-five well-trained Siberian falcons, hoping that they would scare away those "rogue crows".

Interestingly, among the five falcon rescue teams, two falcons named Martha and Alpha have been selected as "permanent guards" because of their excellent driving protection. (Yuan Hai)

Expo 200 1No. 10

There are many crows over Tokyo.

Author: Du Bin compiled

Since the Edo era, the sky in Tokyo has been the favorite haunt of crows. In recent years, the number of crows has increased sharply, and citizens have complained about it, which has attracted the attention of the metropolitan government. In order to reduce the number of crows in Tokyo, the government has taken relevant measures. Can these measures produce results?

10g The world reflected by the brain

Professor Akio Sugita from the Department of Agriculture of Utsunomiya University began to test the recognition ability of crows in August 2000. It turns out that after three days of practice, from the fourth day, crows can basically find the designated container of disguised food accurately. Crows can even tell a circle from a 24-sided one.

In order to further understand the recognition ability of crows, Professor Sugita dissected the brains of 17 crows and found that the average weight of crows' brains with standard weight is about 10g, which is almost three times the weight of chickens' brains. Professor Sugita explained: "Needless to say, the size of the brain and the density of brain cells in birds such as crows and chickens are also very different. In the cerebral cortex of crows, there are 4 ~ 5 layers of nerve fibers. When processing information, nerve fibers at all levels of the brain share tasks as much as possible.

Are crows smarter than stone age people?

Crows also have the ability to master causality: for foods with hard shells, such as walnuts and shellfish, they are thrown from a height and fall to the ground to break open. This action is easy for crows. In Sendai, crows can often be seen crushing walnuts with the help of moving cars and then flying over to eat the fruit inside.

Crows living in New Caledonia also use tools. According to the British "Science" magazine, crows on the island process the leaves of plants into slender shapes, use them to drive away insects hiding in tree holes and other places, and then eat them. This crow can also use hooks and sharp objects flexibly. Dr. Hunt, the author of the article, thinks that "they have reached the level of human beings in the Stone Age".

Crows also have a very good memory. We can often observe the "food storage behavior" of crows: they hide food first and then take it out when necessary. The researchers set aside a certain area in the Zen Temple in Nagano City to observe the "food storage behavior" of a pair of crows. The results show that there are 1 14 places where crows store food. They can not only remember these places, but also take out food from perishable things in order and eat them. This is really amazing!

It is said that the same crow, Jay living in Canada, can even remember 1000 ~ 2000 food storage places. Mr. Tang, a representative of Japan Urban Bird Research Association, called these crows with super memory ability "primates among birds". He pointed out: "Crows thrive in nature with a brain weighing 65,438+00 grams as a weapon. In New Caledonia, they make tools and feed on insects. In Tokyo, they will pay attention to urban garbage. It is worth noting that crows on the street have become more and more afraid of humans. "

Why do crows breed?

The Nature Education Park affiliated to the National Science Museum of Japan began to investigate the large crow nests in Tokyo from 1985. According to the survey data, there were only 7,000 crows at that time. Five years later, 1989 reached 10000, and 1995 quickly doubled to 20000. It is said that there are only 3000 crows near Tokyo 1955. If this statement is true, the number of crows has increased sixfold in 40 years. The above survey does not include small and medium-sized bird's nests, so 20000 is only a fairly conservative figure.

Why is the number of crows growing so fast? If the number of chicks increases and crows live longer, the number will naturally increase. Downtown Tokyo is the best environment for crows. First of all, in Tokyo, birds of prey, such as owls, vultures, eagles, carnivores, such as foxes, are not natural enemies of crows at all, and the survival rate of chicks and the life span of crows will definitely increase. In addition, urban garbage bags are placed on the road, providing a food source for crows.

Crows need about 100 grams of food every day. 70% of crows' foraging behavior is to grab garbage and food from pigeons and other animals. If a crow eats 70 grams of garbage every day, then 20,000 crows only eat 1400 kilograms a day, accounting for only 0.5% of the total daily garbage in 23 districts of Tokyo. Of course, crows don't starve to death. They can even "have children with peace of mind" and "enjoy food" and enjoy a beautiful "city life".

Effective recycling of garbage is a necessary means to deal with crows.

On the eighth street in Ginza, there are many restaurants, and you can hear the first crow at four or five in the morning. Watching the waitresses in suits and ties take taxis home in twos and threes, crows flew here one by one from their nests, and crows around them were crying and making a lot of noise. A crow pecked a hole in the garbage bag, and soon a large crowd of crows would come around.

Worried that the image of Ginza will be affected, the early morning garbage collection organized by private businessmen was officially launched in September. 1997. It is said that about 70% of about 3,000 restaurants, offices and shops participated in this activity. In Tokyo, it is very late to recycle garbage, often after the garbage is pecked everywhere by crows, which is why Ginza is the only one who recycles garbage in the morning. Since then, the phenomenon of crowing has indeed decreased, but the number has not decreased.

If the crow problem can be regarded as an urban problem, why is only Tokyo capitalized on this issue? It is said that crows are not conspicuous in Osaka, because garbage collection in busy neighborhoods is carried out from 2 am to early morning, and the peak period of transporting garbage to incineration plants is generally concentrated from 5 am to 6 am. Most metropolises in developed countries adopt household collection, and there is a garbage collection box in front of each household's residence. Naturally, crows don't peck garbage everywhere like Tokyo.

Reducing the amount of urban garbage and keeping the garbage collection station clean are all effective measures to deal with crows. I'm afraid there will be a long-term war between Tokyo and Crow for more than 10 years.

Roasted crow skewers and bird crows.

The governor of Tokyo, Shintaro Ishihara, once told foreign journalists that he hoped to make crows into pies as a specialty of Tokyo. I don't know if he is serious or joking. However, among developed countries, Japan may be the only "crow consuming country". It is said that before the 30th year of Showa (1955), a crow skewer baked in sauce was often bought at the temple fair of Guojiubu Temple in Nagano Prefecture. However, these dishes are gone. The riot in Champs Street 199 1 in Akita Prefecture is because "signs of eating crows" still exist. Champs Street Office plans to make crow meat into canned food and pickles. , and sold as a specialty, tasting will be held soon. Later, due to the strong opposition of the street people, the plan stopped.

Crow once appeared as a "waiter of God" in the ceremony of offering sacrifices to God. At the Yandao Shrine in Hiroshima Prefecture, from 400 years ago, on May 15 every year, people would sail between the islands of the Yandao Shrine, throw the boards carrying the Jiangmi group into the sea, and then sit on the boat and play music to summon birds and crows. It is said that rice balls worship crows in order to pray for disease-free and disaster-free, and the whole family is safe. Not only in the shrine, people all over the country scatter rice and rice cakes on farmland every year on the first day of the first month to welcome the crows of God. However, with the rapid economic development, great changes have taken place in Japanese society, and many gods and sacrifices about crows have been forgotten.

"I really want to kill all the crows in the world and sleep with my beloved." It is said that this is a folk song written by Takayama Shinsuke, a scholar at the end of the curtain, when he was in Shinagawa. Tokyo has been a busy city for crows since the Edo era. Compared with when Nobuyuki Takayama lived in Tokyo after 140, the number of crows has further increased, and the population has also increased by leaps and bounds. On the contrary, the number of other wild birds such as swallows is decreasing year by year.

The natural enemy of crow comes from the sky, flying higher than it, not on the ground.

Under the principle of protecting animals, it has not been treated, so it takes a long time. This phenomenon also appears on Chang 'an Avenue in Chongwenmen. So now it is incurable and incurable. This is very tricky!