in Greek mythology, the Stymphalian birds were man-eating birds with beaks of bronze, sharp metallic feathers they could launch at their victims, and poisonous dung. They were pets of Ares, the god of war. They migrated to a marsh in Arcadia to escape a pack of wolves. There, they bred quickly and swarmed over the countryside, destroying crops, fruit trees, and townspeople. They were also defeated in Hercules Sixth Labor for Eurystheus. Heracles could not go into the marsh to reach the nests of the birds, as the ground would not support his weight. Athena, noticing the hero's plight, gave Heracles a rattle which Hephaestus had made especially for the occasion. Heracles shook the rattle and frightened the birds into the air. Heracles then shot many of them with his poisoned arrows. The rest flew far away, never to plague Arcadia again. Heracles brought some of the slain birds to Eurystheus as proof of his success. The surviving birds made a new home on an island in the Euxine Sea. The Argonauts later encountered them there.