I can only guess that chickens and monkeys are more of a cultural presence in some parts of the world than ours. Perhaps over there a monkey gets a bit too rambunctious and misbehaves and exasperates the people. You can’t exactly yell at a monkey and tell it to stop and calm down. But if you kill a chicken that MIGHT get the stupid monkey’s attention where words fail.
Google Indian Monkey Attacks or something similar, and you see the efficacy of the man’s statement.
Monkeys can get nasty. And, not that I’ve seen it, but a dead chicken bleeding onto the bushes would intimidate the monkeys into silence or dispersal. Just the act may be enough.
Prolly more of a rural solution than an urban one, lol.