The Effect of Directional Training on Initial Orientation in Pigeons

SEVERAL investigators (Riviere, 1929; Kramer and St. Paul, 1950; Matthews, 1951; Hitchcock, 1952; Riper and Kalmbach, 1952; Pratt and Thouless, 1955; Michener and Walcott, 1966, 1967) have all reported that when pigeons trained to fly in a single direction were released from points off the training line, the birds continued to fly in the training direction. Wallraff (1959) and Graue (1965) both have reported that even a single flight will influence the vanishing direction of later flights, but Gundlach (1932), Heinroth and Heinroth (1941), Yeagley (1947), and Matthews (1951) present data that do not support such a directiontraining effect in pigeons. Matthews (1964) also found no indication of a direction-training effect in Manx Shearwaters. Many of the experiments on this question have been conducted with inadequate controls and with insufficient sample sizes. In several cases data were pooled from many different releases, a procedure that ignores the influence of temporal changes and local variations; when these data are reanalyzed according to releases o.n the same day from the same site., one often finds statistically random vanishing bearings. Some of the published results that seem to show a direction-training effect are not subject to such criticisms, but they are contradicted by results published by other investigators. Thus, although many workers have investigated the effects of direction training, the question of its effect remains unresolved. After an examination of the literature, we remained unconvinced of the general occurrence of a direction-training effect, and strongly felt that more experiments should be conducted.