Free Study Guide for Silent Spring by Rachel Carson - Book Summary
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CHAPTER NOTES - SILENT SPRING
These people would be even more concerned if they knew exactly how ineffective spraying is. In some places, spraying actually increases the rate of death of elm trees. This result happens because spraying kills all the natural enemies of the elm disease. More troubling is the fact that the Midwestern towns could have found a perfectly sound method of controlling the disease by looking to the example of eastern cities, cities that were hit by the disease first. In New York, city officials began a program of sanitation: clearing away all dead and diseased trees and limbs as soon as they were spotted. As a result, they contained the disease so that it became insignificant. The same program was applied n Syracuse. Before the program, the city of Syracuse lost 3,000 elms. After the program, it lost less than one percent of the trees. The sanitation method is not only effective, itís also cheaper than spraying. Cities would eventually have to clear away dead and dying trees and limbs anyway. If they do it more promptly, theyíre not spending any more money than would normally be in their budgets.
Another long-term solution would be to use a variety of trees instead of planting only one kind. That way, if something attacks one variety, it will be unlikely to wipe out all the landscaping trees of a town or city.
Another American bird is also on the verge of distinction: the American eagle. One group of eagles have been intensively studied. They are those living on the Florida coast. One ornithologist banded more than 1000 eagles from 1939-49. When he first began banding birds, he would find 125 active nests and would band 150 young eagles. In 1947, the number of eagles began to decline. He found over the next ten years that many nests never had eggs in them and that often, the eggs that were viable hatched birds that died soon afterward. By 1958, this scientist searched over 100 miles of coastline before finding and banding only one eaglet.
A curator of a Florida bird sanctuary continued the work of documenting the loss of eagles in Florida. The eagles that come through the sanctuary have been counted over the years and these numbers tell the story of the eaglesí destruction. From 1935 to 1939, 40 per cent of the eagles were yearlings. Between 1955 and 1959, only 20 per cent were yearlings. Other sanctuaries report similar findings.
Itís hard to study the eagles directly to find out what the cause of their extinction is, but scientists can study other bird species and then apply those results to the situation of eagles. One scientist studied the affects of insecticides on quail and pheasants. He found that exposure to DDT and other chemicals sometimes doesnít seem to affect the birds, but later, the affects are seen in the birdsí sterility. They either donít produce any eggs, or the poison is stored in the egg yolks and the eggs never hatch. Itís very difficult to apply these findings to eagles, but the evidence is compelling that insecticides are responsible for the extinction of eagles.
Other countries have also experienced shocking numbers of bird deaths. In France, partridges disappeared after vine stumps were treated with arsenic. In England, the problem occurs with insecticide treated seed. Huge numbers of birds eat these poisoned seeds and die. Not only birds, but foxes have also died from the insecticides. Since foxes are necessary for keeping the numbers of rabbits down, people have begun to call for a ban on these insecticides.
In this chapter, Rachel Carson shows another step in the line of attack of insecticides. Sheís described their affect on the soil, the plant life, other forms of life. Here, she describes insecticidesí destruction of wild birds. Here as well as above, Carson uses two dominant means of persuasion: logical and ethical. She describes the scientific methods used to determine the link between insecticide spraying and bird deaths. She also reminds the reader over and over of the value of wild birds in the world as members of ecology we all live in.
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. 15 May 2008