In 1958, Mao Zedong started the extermination campaign of which bird species?

Poison being put out and killing cats is still happening in Greece and Cyprus. Don't they realise its against the law and history will repeat itself when rats become rampant.

Rats, flies and mosquitos I get, but why sparrows?!? That should have been explained in the answer.

UnopposedYogi27101, He was a true sick-o!!