Which of the following is not a cause of loss of biodiversity?

The correct answer is Option (2) → Keeping animals in zoological parks

The four major causes of biodiversity loss, called ‘The Evil Quartet’, are habitat loss and fragmentation, over-exploitation, alien species invasions and co-extinctions. Keeping animals in zoological parks is not a cause of loss. It is a method of ex situ conservation, in which threatened animals are protected and given special care.

Option (1) Over-exploitation — Incorrect. Over-exploitation is a cause: when ‘need’ turns to ‘greed’, species such as Steller’s sea cow and the passenger pigeon are wiped out.

Option (2) Keeping animals in zoological parks — Correct. Zoological parks protect threatened animals; many animals extinct in the wild still survive in them.

Option (3) Loss of habitat — Incorrect. Loss of habitat is the most important cause driving animals and plants to extinction.

Option (4) Invasive species — Incorrect. Invasive (alien) species such as the Nile perch in Lake Victoria cause the decline or extinction of native species.

NCERT Extract:
Loss of Biodiversity – “… Causes of biodiversity losses: The accelerated rates of species extinctions that the world is facing now are largely due to human activities. There are four major causes (‘The Evil Quartet’ is the sobriquet used to describe them). (i) Habitat loss and fragmentation: This is the most important cause driving animals and plants to extinction.”
How do we Conserve Biodiversity? – “… Ex situ Conservation– In this approach, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. Zoological parks, botanical gardens and wildlife safari parks serve this purpose. There are many animals that have become extinct in the wild but continue to be maintained in zoological parks.”