Why are (i) alien species invasion and (ii) Loss of habitat and fragmentation, considered to be the major cause of loss of biodiversity? Explain with the help of one example each.
New species entering the geographical region are known as alien species. Introduction of alien species causes a significant loss to the biological community. However, some of the species are able to establish the area. Such successful exotic species eliminate the native species to the point of extinction, and so alter the habitat that many native species are no longer able to persist.
For example introduction of Nile perch into Lake Victoria disturbed the ecosystem of the lake by eliminating several native species of small cichlid fishes.
The destruction of natural habitat is the primary threat to biodiversity. When the natural habitats are diminished then the flora and fauna have no place to survive and thrive and it will lead to the extinction.
California Condor a sky scavenger, which is the largest flying bird has been severely affected by human cleanliness.