Meeting Abstract
Most animals on earth are small but we know little of their behavioral abilities. There is no general consensus on whether small animals have similar, better or worse behavioral functionality compared to larger animals. No study to date has determined the scaling of behavioral capacities using controlled assays for well-defined behaviors or using phylogenetic analysis for broad applicability. Among insects, there is simply not enough data available to determine how well small organisms perform relative to larger animals. We determined the scaling relationships of visual morphology, learning performance and body size using stingless bees, a tropical tribe of social bees. This group has three orders of magnitude in body size variation among many species and will readily perform in behavioral tests. We collected stingless bee foragers from ten species varying in body mass from 2-115mg and calculated the resolving power of their eyes using radius of curvature estimation. Bees were individually introduced to a Y-maze with black and white vertical line patterns that were designed to span the range of spatial acuity of each bee species. We determined what the patterns look like in ‘bee vision’ using an achromatic visual model. We tested bees’ ability to differentiate patterns and compared this to their anatomical resolving power and body size. Then we determined the learning rate for each species in the maze. Using phylogenetic generalized least squares analysis, we found that there was no correlation between body size and pattern learning performance among the stingless bee species studied. Small species performed equally compared to larger species in differentiation and learning tasks despite lower resolving power. This suggests neurophysiological or behavioral compensation for small body size.
