1. Loss of habitat. 

2. Trees that provide food and shelter to so many species are destroyed due to human intervention.

Over hunting and poaching: 

Large number of animals is hunted for their horns, skin, teeth and many other valuable products.

3. Pollution: 

• Number of animals are affected by pollutions like air pollution and water pollution. 
• In the recent years more number of animals is affected by wastes in the form of plastic. 

4. New habitat: 

• Sometimes animals are taken by people to new habitat where they do not naturally live. 
• Some, of them may extinct and some may survive
• The new ones may also get attacked by the species already living there and cause their extinction.

5. Chemicals: 

• We use pesticides and other chemicals to get rid of damaging insects, pests or weeds. 
• But they can also poison desired plants and animals if we do not use them correctly.

6. Diseases: Diseases due to various unknown reasons may affect the animals and make them extinct. 

7. Natural calamities: Animals may also be destroyed due to natural disasters like flood and fire.