Vultures:

Three species found in northern and north-eastern Cambodia, red-headed vulture (Sarcogyps calvus), white-rumped vulture (Gyps bengalensis), and slender-billed vulture are under IUCN's list of critically endangered species. Their presence holds significant importance in the ecosystem as they help clean carcass of animals. A Diclofenac drug was extensively used in South-Asia(2006) to treat livestock, and as these vultures fed upon them, their population decreased at a rate of 95 per cent due to poisoning. Thereafter the drug was banned.