Sun Navigation of Apis Mellifica L. In the Southern Hemisphere
The sun navigation of honey bees has been investigated in a region of the southern hemisphere where the sun was moving counter-clockwise during the observations. Foragers from a strain long established in the region were fed in the evening on a dish in a particular geographical direction and transferred overnight to a new locality unknown to them. During the next day the majority of bees were at all hours searching in the direction of their previous training. Foragers which were the offspring of queens recently improted in an inseminated state from the northern hemisphere showed after similar training systematically false orientation on the day of observation. The direction of their search shifted by about 30° per hour counter-clockwise from a direction about 90° clockwise from the training direction in the morning to the correct direction in the evening. Bees of hybrid (local and imported) origin also showed false orientation. The existence of innate mechanisms is postulated compensating in northern bees for the sun's clockwise movements and in southern bees for the counter-clockwise movement of the sun. The change in the direction of compensation must have occurred during the last 425 years, and a possible mode of this evolutionary process is discussed.