Question

What are invasive alien species?

Answer 1

When alien or non-native species are introduced or invade in any area, it spreads throughout the natural habitats and threatens the biodiversity of that area. The new introduced species or the species that has invaded starts competing with the native species for food and shelter thus resulting in negative impacts on the native species.
Example - In Hyderabad city, invasion of pigeons has lead to decrease in the number of crows.