This saying has too many words at the beginning and too few at the end. The structure would be naming a situation, then a comparison and its explanation by the absurd. I don't know Doña Emilia, who seems to have been pecked by her turkeys, but there is a certain Manuel who has more mentions: "hungrier than Manolete's turkeys, which ate a bolt with pecks and one that was not enough, burst chirping", "hungrier than Manolo's turkeys who ate the train tracks thinking they were worms", "hungrier than Manolo's turkeys who went behind a train thinking it was a worm", "hungrier than Manolo's turkeys who ate the radio set when they sang Clean Wheat", . . .
