I came across a Satin Bowerbird bower the other day. The male has been hanging around the area for the past couple of months.
Birdlife Australia notes:
Satin Bowerbirds are renowned for decorating their bowers with all manner of blue objects collected from the vicinity of the bower and sometimes from farther afield. These odds and ends may comprise feathers from parrots, flowers, seed-pods and fruits, butterfly wings and artificial items such as ball-point pens, matchboxes, string, marbles and pieces of glass. Occasionally objects of different colours, especially greenish-yellow, are also used where blue items are difficult to procure. These are carefully arranged around the bower to assist the male to attract a mate.
The photos below show a wide variety of blue objects at the bower ranging from feathers to pegs.