Metal crested song birds that chirp steel clangs and ditties of industrial decay. Can be attracted by the mating call of a rusty music box. Lay eggs bolted on four sides in maternally placed rings of barbed wire and raspy sprockets. Chicks wear their species name along a congenitally given brand label that will later lure attention based on the strength of its graphic design. Occasionally mimetic bird species will imitate the logos of their more successful cousins. These are known as bootleg birds.