This sculpture was made in Paris and cast in bronze at a later date. The vertical, supporting element comes from a piano, while the perforated elements are cast from pieces of wood. The head of the bird was modelled in plaster. The other casts from the edition have a conventional brown–green patina, but this particular cast was given a silvered finish in the mid–1960s, at a time when Paolozzi was making works in chromium–plated steel and polished bronze and was also painting his large sculptures.