What strategies do homing pigeons use during ontogeny?

Abstract

[It is still a matter of discussion whether pigeons use information collected en route to a novel release site to obtain directional information for the homeward journey. Moreover, it is unclear what role the loft plays in this process. Attempts were made to clarify these issues, in the present study with two age groups of pigeons, one group of 3-month-old birds and one group of adult birds. All the pigeons came from our stock and were randomly divided into two distinct lofts; a tower loft (H-loft) exposed to environmental cues and a garden loft (L-loft) protected from them. To observe whether pigeons preferentially use route-specific or site-specific information during homing flights, experimental birds were transported via a detour, while controls were displaced via a straight route between the lofts and release locations. From these experiments, we observed that during their homing journey, the young L-loft pigeons preferentially used information collected en route (χ 2 (1) = 9, p < 0.01), distinct from the information used by adult pigeons from the same loft (χ 2 (1) = 8.18, p < 0.01). For pigeons from the H-loft, no difference was noted. A different homing behaviour was also observed between the young pigeons from H- and L-lofts (χ 2 (1) = 5.14, p < 0.05) with the L-loft ones showing a clear tendency to overestimate the initial phase of the outward journey detour when compared with the H-loft pigeons. The results also suggest that young pigeons seem to rely on route-specific information during homing flights, while adults preferentially use site-specific information. It was also observed that the loft features conditioned the way pigeons navigated, perhaps allowing birds to rank the information available in a distinct way., It is still a matter of discussion whether pigeons use information collected en route to a novel release site to obtain directional information for the homeward journey. Moreover, it is unclear what role the loft plays in this process. Attempts were made to clarify these issues, in the present study with two age groups of pigeons, one group of 3-month-old birds and one group of adult birds. All the pigeons came from our stock and were randomly divided into two distinct lofts; a tower loft (H-loft) exposed to environmental cues and a garden loft (L-loft) protected from them. To observe whether pigeons preferentially use route-specific or site-specific information during homing flights, experimental birds were transported via a detour, while controls were displaced via a straight route between the lofts and release locations. From these experiments, we observed that during their homing journey, the young L-loft pigeons preferentially used information collected en route (χ2(1) = 9, p < 0.01), distinct from the information used by adult pigeons from the same loft (χ2(1) = 8.18, p < 0.01). For pigeons from the H-loft, no difference was noted. A different homing behaviour was also observed between the young pigeons from H- and L-lofts (χ2(1) = 5.14, p < 0.05) with the L-loft ones showing a clear tendency to overestimate the initial phase of the outward journey detour when compared with the H-loft pigeons. The results also suggest that young pigeons seem to rely on route-specific information during homing flights, while adults preferentially use site-specific information. It was also observed that the loft features conditioned the way pigeons navigated, perhaps allowing birds to rank the information available in a distinct way.]