FURTHER EXPERIMENTS ON OLFACTORY NAVIGATION AND NON-OLFACTORY PILOTAGE BY HOMING PIGEONS

Supplementary to a previous investigation (Wallraff and Neumann 1989), further experiments were conducted with homing pigeons that were eith er familiar of unfamiliar with the release area, and that had or lacke d olfactory access to environmental odours. All four possible pairwise combinations of these factors were tested. The previous results were confirmed, showing that in an unfamiliar area olfactory inputs are nec essary for home-related orientation, while in a familiar area both olf actory and non-olfactory information can be utilized and each is more or less redundant as long as the other kind of information is also ava ilable. The degree of redundancy of olfactory inputs varies, obviously depending on the pattern of individual local experience.