Sparrows are good and bad. Are they good birds?

Sparrows are the most familiar birds and probably the most controversial birds in China. 1958, people once listed it as one of the four pests.

The government mobilized urban and rural residents throughout the country to dig out their nests, arrest and beat them, beat gongs and drums and set off firecrackers within the specified date and time, leaving them nowhere to hide.

Without a chance to breathe, he finally fell to the ground and died. A year later, pests were found in garden plants, some of which were very destructive. This power

So that scientists and decision-making organs have to seek better countermeasures again. Before the problem was clarified, people first replaced sparrows, one of the four pests, with bedbugs.

Sparrows were freed from the accusation of four pests and were given innocence and freedom. The remaining problems will be gradually clarified through long-term research by scientists.

Thirty years have passed, and people have heard calls from time to time to rehabilitate sparrows. Don't sparrows eat cereal? What's wrong with the nationwide campaign to eliminate sparrows?

Are you online? This naturally involves how to evaluate the advantages and disadvantages of birds, how to correctly promote their advantages and suppress their disadvantages. Let's talk about sparrows first

Sparrows are a general term for birds, all of which feed on grains. Among them, there are two kinds with the widest distribution and the strongest adaptability, all over the northern hemisphere.

It is the most common and abundant domestic sparrow in Europe and America and the most common tree sparrow in Asia. Screaming Trees hemp, a sparrow, inhabits the vast plains of China.

Sparrows. Sparrows belong to Oncology. Most species of this family live in Africa and belong to tropical birds. Some of them have been domesticated and bred into many species.

Become a precious caged bird. Birds of Oncology have the habit of nesting in groups, and their nests are covered, that is, they weave spherical nests with hay between branches.

The bird's nest is open on the side. Other species nest in tree holes. Tree holes are a good protective barrier for birds and nests, so the nests woven in tree holes are better than those woven in trees.

Simple, usually just a bowl-shaped quilt. Domestic sparrows nest in tree holes, and with the appearance of human buildings, they quickly adapt to nesting and breeding in room holes.

Go to nearby orchards, vegetable fields and fields for food. Birds of Oncology mainly feed on plant seeds, and many of them are fond of cereals. tropical crops

When they mature all the year round, their losses are extremely serious.

Most passerine birds feed their young birds with insects or their larvae during the incubation period, and sparrows are no exception. In temperate regions, sparrows can breed every year.

Breeding 3-4 litters, with an average of 4-6 chicks per litter. Each chick will be fed by its parents for about 12 days before leaving the nest. The number of insects eaten during this period.

Of course, I was very impressed. Therefore, some scientists believe that sparrows should be protected during the breeding season from April to August every year, which is conducive to eliminating pests in the field. When they harm crops in autumn, they will be controlled.

This idea is certainly not bad, but if it is to be implemented, I am afraid the following questions must be answered. First of all, among the insects killed by sparrows when they feed their chicks, are there any beneficial insects that specialize in catching pests? Secondly, even assuming that all the pests it preys on are pests, how many of the total pests in the field have been eaten by sparrows, and can the remaining pests still make waves? This problem is very important, because whether it is chemical control or biological control of pests, people are generally interested not in how many insects are eliminated every day or month, but in whether the density of pests in the field is reduced to an alarming level. If sparrows specialize in eating pests in the field and can suppress the density of pests in the area they eat, are sparrows evenly scattered in all corners of the field when catching insects in the field, or are they only concentrated near the homestead near the foot of the field?

Of course, it is not easy to answer the above questions satisfactorily, and we need to invest huge manpower in long-term large-scale research, which we do not have at present. However, based on small-scale observation and experiments in individual areas, the problem is really complicated. Experiments conducted by scientists in wheat fields in Shunyi District, Beijing, show that when sparrows mainly feed young birds with field aphids, the number of aphids in their feeding areas is not significantly reduced because of sparrows' predation. Moreover, from the field observation of wheat fields in Beijing, Shanghai and Xinjiang, it is found that the number of active individuals in the field is directly proportional to the distance from residential areas, and the farther away from residential areas, the fewer sparrows there are. So far, there is no conclusive evidence that sparrows can effectively inhibit pests in the field during the breeding process, nor can they prove ineffective in eliminating pests. It seems that this can only be discovered through continuous and in-depth research.

In urban gardens, forests, grasslands and other areas far away from agricultural areas, the main food of sparrows is not grain. When breeding, they feed their young with insects, saving energy, and eliminating a large number of weed seeds in autumn and winter. Especially now, there are fewer and fewer birds in the city. Sparrows can bring vitality and are an ornament of nature. It should be said that the advantages outweigh the disadvantages. It must also be emphasized that in the past, when considering the advantages and disadvantages of sparrows or other animals, their eyes were narrow, and they often only paid attention to what they ate, whether they could eat it or not, and how much fur was worth. However, from an ecological point of view, you will feel that the problem is much more complicated than this. This requires a species to be regarded as a member of the ecosystem and to understand its role in ecosystem stability and energy flow. Especially for species such as sparrows, which are widely distributed and numerous, we should be more cautious. For example, sparrows in the Netherlands prey on tree sparrows every year, accounting for 30 ~ 50% of the experimental research area. Among the owls (barn owls) investigated by European scientists, 14% are domestic sparrows. At the same time, it is found that many other raptors often prey on sparrows. Raptor is an important beneficial bird, which plays an important role in eliminating natural pollution. Sparrows are the basic food for birds of prey to survive in winter. Judging from the virtuous circle of the whole ecosystem and the benefits it brings, the importance of sparrows is obvious.

At the same time, we also need to understand the role of sparrows in epidemiology. For example, in recent years, it has been found that tree sparrows can spread livestock and poultry diseases. The above facts tell us that it is more complicated to judge the quality of an animal, because their relationship with human beings is inherently complicated. Moreover, the advantages and disadvantages are relative. Under the condition of insufficient research, it is very wrong to easily blame sparrows and engage in destructive "elimination" in the form of mass movements. From a biological point of view? %