Assessing fluctuating asymmetry of white-tailed deer antlers in a three-dimensional context

Ditchkoff, S. S., and R. L. deFreeze

Fluctuating asymmetry, random departure from perfect symmetry in bilateral traits, has been proposed as an indirect indicator of individual quality. Sexually selected traits, such as deer antlers, are hypothesized to demonstrate decreasing level of fluctuating asymmetry with increasing trait size and decreasing level of fluctuating asymmetry with increasing age. These hypotheses have been previously tested for antlers using linear measurements to quantify fluctuating asymmetry. However, antlers are complex, 3-dimensional traits making it difficult to quantify all forms of visual asymmetry using traditional, linear measurements. It is this visual asymmetry that would be assessed by potential mates and rivals. Therefore, we created 3-dimensional computer models of white-tailed deer (Odocoileus virginianus) antlers to measure visual fluctuating asymmetry. Asymmetry measures of various antler traits were computed using the models by measuring distances from the trait to a vertical and horizontal plane created using coordinate points generated within the model. We found no association between degree of fluctuating asymmetry and trait size, nor was any association found between degree of fluctuating asymmetry and age using either the 3-dimensional measures of asymmetry or traditional, linear measures of asymmetry. Examination of these data suggests that fluctuating asymmetry of white-tailed deer antlers is not a reliable indicator of quality. DOI: 10.1644/09-MAMM-A-134R.1.

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Ditchkoff, S. S., and R. L. deFreeze. 2010. Assessing fluctuating asymmetry of white-tailed deer antlers in a three-dimensional context. Journal of Mammalogy 91:27-37.