What are the reasons for high extinction rates at present?

It is believed that communities with high diversity tend to be less variable, more productive and more resistant to biological invasions. Earth’s fossil history reveals incidence of mass extinctions in the past, but the present rates of extinction, largely attributed to human activities, are 100 to 1000 times higher. Nearly 700 species have become extinct in recent times and more than 15,500 species (of which > 650 are from India) currently face the threat of extinction. The causes of high extinction rates at present include habitat (particularly forests) loss and fragmentation, over -exploitation, biological invasions and co-extinctions