Initial orientation of homing pigeons on the Atlantic coast of Morocco is affected by a strong preferred compass direction (PCD)

Abstract Three seasons of homing pigeon releases were carried out on the Atlantic Coast of Morocco to determine what effect the unusual prevailing wind pattern in this region, essentially continual north winds during the spring and summer, would have on navigational behaviour. Release sites were scattered in a semi‐circle from the northeast to southwest of home, but regardless of release site, the pigeons displayed a consistent initial orientation preference to the west‐northwest. Although such directional biases in initial orientation, known as Preferred Compass Directions (PCDs), have been well described, we know of no case where a PCD has been shown to be the primary determinant of pigeon initial orientation as was observed in Morocco. We speculate that the strength of the PCD in our coastal Moroccan pigeons is related to the prevailing wind pattern, but in a way we are yet unable to explain.