The debate over olfactory navigation by homing pigeons

Abstract

In the years since 1971, when Papi and his colleagues first proposed that odors played an important role in the homing navigation of pigeons, the hypothesis has remained controversial. Although the idea seemed intuitively unreasonable to nearly everyone working in the field at that time, empirical support from a wide variety of experiments emanating from Papi's laboratory in Pisa has stimulated a quarter of a century of experiments, theorizing, advocacy and dissent. The issue is reviewed here in contributions by Hans Wallraff, one of the chief proponents of olfactory navigation, and Roswitha Wiltschko, who remains skeptical about the involvement of odors in pigeon homing. At the Editors' request, I provide here a personal perspective on the debate from one who has had no involvement in the issue and, indeed, has never released a homing pigeon.