Stymphalian Birds. The Stymphalian birds are a group of voracious birds in Greek mythology.
The birds' appellation is derived from their dwelling in a swamp in Stymphalia. The Stymphalian Birds are man-eating birds with beaks of bronze, sharp metallic feathers they could launch at their victims, and poisonous dung.These fly against those who come to hunt them, wounding and killing them with their beaks.
All armour of bronze or iron that men wear is pierced by the birds; but if they weave a garment of thick cork, the beaks of the Stymphalian birds are caught in the cork garment, just as the wings of small birds stick in bird-lime. These birds are of the size of a crane, and are like the ibis, but their beaks are more powerful, and not crooked like that of the ibis; Pausanias.
Description of Greece, 8.22.5 These birds were pets of Artemis, the goddess of the hunt; or had been brought up by 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. The Stymphalian birds were defeated by Heracles in his sixth labour 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 called krotala, which Hephaestus had made especially for the occasion