Habitat loss and fragmentation is a very important cause of species extinction. The deforestation of tropical forests is expected to be the greatest cause of mass extinctions caused by human activity. Cutting down forests and hedgerows to provide agricultural land has increased. The loss of tropical forests, which holds $50 \%$ of the world's biodiversity proving to be the most significant threat to species in the modern age. This leads to fragmentation of habitats and species which require large habitats such as bears cannot survive if the area is too small.
Related Theory
The accelerated rate of species extinction that the world is facing now is largely due to human activities. This is due to Habitat loss and fragmentation, overexploitation, introduction or invasion of alien species, pollution, climate change and co-extinction.