PIGEON HOMING: THE EFFECT OF OUTWARD-JOURNEY DETOURS ON ORIENTATION

Abstract

SUMMARY Fifty-four experiments, involving the release of a total of 1,671 single pigeons, were performed to study the influence on their orientation of cues picked up during transportation to the release site. The method used was that of the detour experiment, which consists in recording the initial orientation and homing performances of two (or more) groups of pigeons transported to the same release site by two different routes. The routes chosen were strongly divergent on the first leg, and roughly described a semicircle in a clock- or counterclockwise direction. Birds transported by the clockwise route were expected to deflect counterclockwise (CCW birds) with respect to the home bearing, or, at least, with respect to birds transported by the counterclockwise route; these were expected to deflect clockwise (CW birds; Maps 1–17). To evaluate the effect of a detour on pigeon orientation, 52 comparisons between sets of CW and CCW bearings were available; a significant difference was found in 34 cases. Con...