Suspended from the ceiling of the medieval Cathedral of Saint Michael and Saint Gudula by thin wires, the paper creations have come from as far afield as Hong Kong, New York and Tokyo, after Belgian designer Charles Kaisin asked people to send in home-made birds, or deposit them in boxes in 160 shops around Brussels.
"I had a very serious heart surgery and I was well taken care of by this hospital. It's why I wanted to help them," Kaisin told Reuters.