KILL TWO BIRDS WITH ONE STONE - MATAR DOS PÁJAROS DE UN TIRO

When we are able to achieve two aims, or goals, at one stroke, we say that we have killed two birds with one stone. "While we visit your mother in Peoria, we can visit mine too, and kill two birds with one stone." Spanish has a very similar saying: "Matar dos pájaros de un tiro." Iker Jiménez, in his "Enigmas sin resolver" (2000) gives us an example on how to use this proverb: "me dio la idea de matar dos pájaros de un tiro y cubrir en un mismo viaje los últimos incidentes ovni registrados en Andalucía." 

Naturally, this is just an idiom, a manner of speaking, and has nothing to do with killing birds today. In years past people did kill birds with a stone and even ate them.