2021年10月 / 马哥(Marlin)整理

08. And No Birds Sing / 鸟儿不再歌唱

(部分节选 - 可能不完整)

The sudden silencing of the song of birds, this obliteration of the color and beauty and interest they lend to our world have come about swiftly, insidiously, and unnoticed. It is hard to exaggerate the significance of this change, for in it we see the end of an era, the final phase in the destruction of that natural environment that has been the cradle of our civilization.

From all over the country come reports of the increasing numbers of birds stricken by the chemicals used to control insects. The reports are distressing and they come from people whose occupations make them especially well qualified to observe and report on bird life: ornithologists, hunters, and fish and game wardens, among others.

One of the most tragic examples of bird destruction comes from the robin, a bird known to everyone, whose return in the spring is one of the first signs that winter is over. In Michigan, a graduate student at Michigan State University, John Mehner, studied robins on the campus as part of his dissertation work. He found that the robin population had declined sharply after the spraying of the campus area with aldrin to control the Japanese beetle. Before spraying there had been 370 adult robins on the campus; two weeks after spraying with aldrin, only two dozen remained, and not a single fledgling was found. The robins that survived were in a sorry state; they were listless, unable to fly well, and many were found with their bills gaping open, gasping for breath.

The cause of the robins’ plight was clear. They were poisoned by eating earthworms that had ingested the aldrin as it was sprayed on the ground and then concentrated in the worms as they fed on the poisoned leaves and other debris. Earthworms are a major item in the diet of robins, and the poison in the worms was passed on to the birds with deadly effect. Mehner also found that the reproductive organs of the surviving robins were severely damaged, and that few, if any, of the birds were able to produce young.

Similar reports of robin deaths came from other areas where aldrin or other chlorinated hydrocarbon insecticides had been used. In one Illinois town, for example, 86 to 88 percent of the robins were estimated to have died after spraying for Dutch elm disease. The elm trees were being sprayed with DDT to kill the beetles that carry the fungus causing the disease, and the robins were being poisoned by eating the earthworms that had fed on the poisoned elm leaves.

The robin is not the only bird to be affected by the use of pesticides. Many other species have also suffered, including some that are much rarer and more endangered than the robin. The scarlet tanager, for example, a beautiful bird with bright red plumage, has been severely affected by the spraying of DDT in the eastern United States. The tanager feeds on insects that are killed by the DDT, and the poison is then passed on to the bird, causing sterility and death.

The use of pesticides is also having an impact on the economy, particularly in the area of agriculture. Many fruit growers, for example, rely on birds to control insect pests in their orchards. When the birds are killed by pesticides, the insect populations increase, and the growers are forced to use more pesticides to control them. This not only increases the cost of production but also leads to further environmental damage.

In addition to the direct effects of pesticides on birds, there are also indirect effects that are equally serious. For example, the destruction of bird habitats by the use of pesticides is causing many species to lose their nesting sites and sources of food. This is particularly true in areas where forests and wetlands are being sprayed with pesticides to control mosquitoes and other insects.

The loss of birds is not only a tragedy in itself but also a warning sign of the damage that is being done to the entire ecosystem. Birds play an important role in maintaining the balance of nature, and their disappearance can have far-reaching consequences for other plants and animals, as well as for humans. We must take steps to protect our birds and their habitats if we are to preserve the natural environment and the delicate balance of life on earth.