Previous Year Question
Vultures which used to be very common in Indian countryside some years ago are rarely seen nowadays. This is attributed to
The destruction of their nesting sites by new invasive species
A drug used by cattle owners for treating their diseased cattle
Scarcity of food available to them
A widespread, persistent and fatal disease among them
Correct Answer: B
Detailed Solution
The principal cause of the rapid decline of vultures in India was the veterinary use of the drug diclofenac.
Diclofenac is a non-steroidal anti-inflammatory drug.
It was used to treat pain and inflammation in cattle.
Residues of diclofenac could remain in the tissues of cattle that died soon after treatment.
Vultures were exposed to the drug while feeding on the carcasses of such cattle.
Even a very small amount of diclofenac can be highly toxic to vultures.
It causes acute renal failure in vultures.
When the kidneys stop functioning, uric acid accumulates in the body.
This leads to the deposition of urate crystals on internal organs, a condition known as visceral gout.
This condition causes the death of vultures.
The White-rumped Vulture, Indian Vulture and Slender-billed Vulture were particularly affected.
The principal cause of the decline was neither a general scarcity of food nor a widespread infectious disease.
Vultures act as natural scavengers by rapidly removing animal carcasses.
A decline in vultures can leave carcasses exposed for longer periods and increase the number of other scavengers, such as stray dogs.
Therefore, the correct answer is diclofenac, a drug used to treat diseased cattle.