What bronze-beaked birds were driven away by Heracles using noise?

The bronze-beaked birds driven away by Heracles using noise were the Stymphalian Birds.

They lived around Lake Stymphalia in Arcadia and were portrayed as dangerous, man-eating creatures. Their bronze beaks, metallic feathers, and poisonous droppings made them especially threatening to nearby people, crops, and settlements.

This was Heracles’ sixth labor. The marshy ground was too unstable for him to approach their nests, so Athena gave him a bronze rattle, or krotala, made by Hephaestus. The noise startled the birds into flight, allowing Heracles to shoot many with arrows, while the survivors fled the region.

They are often confused with Harpies, Sirens, or other monstrous birds. Unlike those creatures, the Stymphalian Birds are chiefly identified by their Arcadian habitat, bronze weapon-like features, and place in the Twelve Labors. Later stories place surviving birds on Ares’s island, where the Argonauts encountered them.