showed that sparrows were basically a beneficial bird for humans.
Rather than being increased, crop yields after the campaign were
substantially decreased. Though the campaign against sparrows ended
it was too late. With no sparrows to eat the locust populations, the
country was soon swarmed. Locusts coupled with bad weather led to
the Great Chinese Famine. Use of pesticides against locust population
further degraded the land.
Instead of working in the fields, millions of farmers had to leave
their villages to work for industries. Very small area was left under
agriculture and food shortages became everyday occurrence.
What is the food chain that has been discussed in the above case?
How did the campaign disturb the food chain in the fields?
How did these disturbances affect the environment?
Is it right to eradicate a living organism in an ecosystem ?How is it
harmful?
Were the sparrows really responsible? What was the reason for the
fall in crop production?
What did scientists find? Did they help in rectifying/correcting the
mistake? Why didn’t they do it so?
What was the impact of human activities on the environment?
What do you suggest to stop/avoid such incidents?
Read the poem “Manavi” in class VIII biology textbook and discuss
in your class, the reasons for the sparrows and the other birds from being
endangered in our surrounding
aSteps towards prevention
her living beings from the harmful effects of the use of toxic material
as pesticides, then the instant reaction may be to Ban the pesticides. It is
easy to say “Ban all pesticides” but the pests still have to be kept in check.
After using pesticides then also we are having a significant amount of loss
of food material because of pests. Now you can imagine if pesticides were
totally banned what would happen to the diseases? Are they really
controlling the pests that effect the crops we vitally need for our growing
population?
The long term solution to this problem is to find other effective
methods of controlling pests which have far less harmful effects and are
based on sound biological principles.
Here are some of the important methods to be used.
Rotation of crops: Growing different crops on a particular piece of land
in successive years reduces the occurence of pests and damage to the
crops from year to year in that area.