The importance of atmospheric odours for the homing performance of pigeons in the sonoran desert of the southwestern united states

The importance of atmospheric odours for homing pigeon navigation in a desert environment was tested using birds from two lofts located in the Sonoran desert near Tucson, Arizona, USA. When released from a familiar training site, experienced control pigeons and pigeons given intranasal injections of zinc sulphate to produce anosmia both displayed good homeward orientation and homed rapidly. When released from two unfamiliar locations, in contrast, the controls continued to display good homing performance while the zinc-sulphate-treated pigeons homed poorly. Significant differences in vanishing bearings, homing time and homing success were recorded. When a group of control and a group of zinc-sulphate-treated inexperienced pigeons were released from two unfamiliar locations, both groups homed poorly. Nonetheless, the controls still outperformed the zinc-sulphate-treated birds, the most notable result being a significant difference in homing success. Taken together, these results highlight the importance of atmospheric odours for the operation of the navigational map of the homing pigeon in a desert environment and, together with previous experiments, demonstrate that the role of atmospheric odours in homing does not seem to vary in any salient way with ambient climatic conditions.