The effect of shape parameters on maximal detection distance of model targets by honeybee workers

The influence of several spatial parameters on the maximal detection distan ce of a target by approaching foraging honeybees was examined. The roles of target diameter, color and luminance contrasts have been already demonstra ted in earlier studies. The present study used, for the first time, dissect ed flower like targets that differed in addition to diameter (D) and area ( pi (D/2)(2) = A(cir)) also in the length of contour line (C), the area or t he colored "petals" (A(cot)) and the degree of dissectedness as expressed m ainly by the ratio A(col)(2)/C. The color and luminance contrasts were iden tical for all targets. Our results confirm the importance of size. However. we demonstrate for the first time, that full circular shapes have the grea test maximal detection distance among targets of equal diameters, and even more than dissected targets,vith equal A(col) and double D. The parameter A (col)(2)/C was found as the best predictor of maximal detection distance of vertically presented targets with varying diameter and degree of dissectio n for honeybee workers. We propose that an increase in the colored area and decrease in contour line is advantageous due to the fact that it increases the amount of contrast that the target as a whole produces against its bac kground.