Macaques are extremely common in Cambodia, with the lowest possible conservation status ranking (least concern). 

This may explain why people have no problem eating them, but it does little to explain why they feel the need to eat the brains out of the still-living animal’s skull.

Macaque brain is a delicacy in Cambodia, and the fresher the meat, the better. 

For this reason, macaques can be drugged or tied up, before having the tops of their heads cut off. 

They are then placed beneath a table with a specially carved hole for the monkey’s head, which acts as a bowl for the brains.