RELATIONSHIPS BETWEEN INITIAL ORIENTATION AND SUBSEQUENT HOMING OF INDIVIDUAL PIGEONS

Correlations on a broad statistical basis were made between the direction taken immediately after release and subsequent homing speed of individual homing pigeons, Columba livia. A positive correlation was found in the sense that pigeons arriving early at their loft were, on average, well oriented towards home while still at the release site, whereas pigeons initially deviating considerably from home tended to return later or not at all. Homing success of inexperienced pigeons was positively correlated with initial homeward orientation even over distances of 150-180 km. No correlation was found between homing performance and individual angular deviation from the sample mean at departure, when the sample mean clearly differed from the direction towards home ('release-site bias'). Pigeons initially deviating from the home direction towards the sample mean did not home faster than pigeons deviating by the same angle but away from the sample mean. The findings indicate once more that site-specific orientation patterns do not solely reflect the directional output of the pigeons' navigation system but are co-determined by directional tendencies that are independent of the positional relationship between release site and home site. This corroborates the conclusion that release-site biases cannot usually be expected to exhibit specific properties of the 'map' component in pigeon homing in a directly realizable way. © 1994 Academic Press, Inc.