Personally, I think Ricky from Trailer Park Boys had the right idea "get two birds stoned at once."
Sorry, as "that guy", it's an old expression, like at 500ish years old. Backin the day, when scarecrows etc were essential, some birds were pests. They'd eat your crops and were really hard to kill. (Also, I think a few were associated with evil.) But as recently as the 1950s sparrows were such a pest in China there was (a shortsighted) official push to kill them.