This book is part of a work in the form of an experiment conducted in an Amsterdam park in 1969. In it, Dibbets observes the habits of a robin, maps, sketches, and photographs its territory. He then alters this space by placing perches there, with the bird thus participating in the drawing/sculpture created by the artist in situ. This book, emblematic of conceptual art, preserves the memory of this ephemeral intervention, in which the idea is more important than the physical realization.