You must not think that because 100 birds were released more than a hundred years ago, and now the United States is losing $800 million a year, what is going on?
132 years ago, in order to remove pests from crops and enrich the diversity of local species. Eugene, president of the American Domestication Association, introduced more than a hundred birds to new York for release, but unexpectedly, it has brought great disasters.
This bird is called starling, small in size, with thick legs and feet, long wings and tail, a sharp and straight mouth, a noisy call, and is good at imitating the calls of other birds. In addition, they are also good at imitating the sounds of other animals, and even learn human language. Their staple diet is insects , fruits , and seeds , and they prefer to inhabit the ground and are social animals. There are about 107 species of starlings, mainly distributed in Africa, North America and throughout Eurasia.
But just some birds, is it really so scary?
According to conservative estimates, the current number of starlings in North America has reached 200 million. Such a huge number of effects can be more than a star and a half, they are terrible, far beyond your imagination!
First, they can seriously damage crop yields. Starlings are highly omnivorous birds that they love to eat, whether they are pests or fruits and cereals. Every autumn, they flock to the fields to eat grain and to the orchards to eat fruit. According to relevant statistics, these starlings in the United States will cause up to $800 million in agricultural economic losses almost every year.
In addition, they can cause planes to crash. In 1960, a bird hit the plane and crashed. At that time, shortly after the plane left the ground, a flock of birds suddenly flew near it, causing serious damage to the engine. In the end, the plane lost control, and all 62 people on board were killed.
Secondly, they also have a serious impact on people's lives. Starlings often fly in dense flocks, chirping all year round and making all sorts of noises; When passing through the city, it will leave a place of feces, almost like rain. Not only that, but the feces also corroded the paint of the vehicles, and the residents were miserable.
Finally, the birds carry diseases that kill livestock. Starling droppings are a source of infection and have caused mass deaths of farm livestock.
So, in the face of such a "vicious" starling, there is no good response?
In fact, the American people have also thought of many ways to deal with starlings, but they have been very ineffective, and one biologist even directly said: "I don't think we have any impact on it." ”
Starlings are also listed as one of the world's worst invasive species because of their behavior in North America.
However, there are also New Zealand stoats that have experienced the same experience.
Since stoats are natural enemies of rabbits, in the late 19th century, New Zealand decided to introduce stoats in order to control the local flood of rabbits. As a result, the rabbit is still active, but several precious birds have been extinct. After all, for stoats, rabbits that are ten times larger than themselves, where are the undefended birds easy to catch.
Not only did the stoat exterminate four rare local birds, but many birds became endangered, and it is for this reason that the stoat is rated as "one of the 100 worst invasive species in the world."
In fact, in the whole world, there are many invasions of alien species, there are natural invasions, there are also artificial introductions, and unintentional introductions, how should we look at this kind of thing?
From Darwin's theory of evolution, there are natural laws among organisms, natural selection, survival of the fittest. The animals in nature check each other, promote each other, and finally reach a balance.
The hasty introduction of alien species, although it can temporarily enrich the diversity of organisms, may be able to achieve a goal for the time being. However, introduced species may be excluded from the system, or because there is no natural predator constraint, it is easy to flood the local area, causing ecological imbalances.
And, not only ecologically, but also socially. Just as starling infestations severely affect the agricultural economy, the proliferation of invasive organisms can cause losses to the economy, directly or indirectly; The source of infection brought by invasive species can also cause health problems for local organisms.
Therefore, in general, the introduction of alien species should not be a whim, and risk assessment should be done, otherwise the losses caused are difficult to estimate.