Are American Homing Pigeons Genetically Different from Italian Ones?

Abstract

The variable results of experiments on anosmic Cornell pigeons, compared with the consistent effect of olfactory deprivation observed in pigeons in Italy, has sometimes been explained by supposing that pigeons in the two countries belong to different genetic strains. This hypothesis was tested by performing experiments with the progeny of Cornell pigeons transported to Italy as eggs and placed in the nests of Italian foster parents. The homing behaviour of the American birds raised in Italy was compared with that of Italian pigeons hatched and raised in the same loft. The results of the experiments show that both the American and the Italian pigeons are severely affected by olfactory deprivation in releases at unfamiliar sites, in contrast to the homeward-oriented control groups of both strains. We conclude that there is no major genetic difference in homing mechanism between Cornell and Italian pigeons. The results of experiments performed in Italy and in the USA have shown that different rearing and training procedures do not induce the development of maps based on different cues. Therefore, the reported differences between the results obtained in the USA and those obtained in Italy may be due to regional differences in the availability of navigational cues.