Question

List of animals and birds seen now and 30years ago in tabular form

Answer 1

Answer:

About 30-40 year ago variety of birds like crane, sparrow and parrot were also seen frequently. Now, only crows are found in our surrounding.

But now a days most of the trees are getting cut down. There is hardly any place for birds to build their nests. Extinction of a species may come suddenly when a healthy species is wiped out completely, toxic pollution renders its entire habitat ; or may occur gradually over thousands or millions of years, such as when a species gradually loses out in competition for food to better adapted competitors.

In modern times, commercial and industrial interests often have to contend with the effects of production on plant and animal life. However, some technologies with minimal, or no, proven harmful effects on Homo sapiens can be devastating to wildlife (for example, DDT).