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

Abstract

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.

Fluctuating Asymmetry of Fallow Deer Antlers Is Associated with Weapon Damage but Not Tactical Behaviour during Fights

“…Thus, high-quality individuals are predicted to produce large, highly symmetric structures that confer greater competitive success during intraspecific encounters, whilst also providing females with a reliable cue of the bearer's genetic quality [65]. Our results show that as males aged there was a corresponding increase in the amount of absolute FA expressed-a finding that is consistent with some studies (e.g., [25,66]), but not others (e.g., [26,54]). We note that other studies that have employed a relative measure of asymmetry have shown a negative relationship between FA and age (e.g., [67,68]).…”

“…Following Palmer (1994 [53]), a two-way ANOVA showed that between sides variation was significantly greater than the measurement error for all traits (coronet circumference: me% = 4.73; F (9,60) = 39.8, p < 0.001; brow tine length: me% = 12.9; F (9,60) = 493.8, p < 0.001; beam circumference: me% = 6.71; F (9,60) = 40.14, p < 0.001; antler length: me% = 5.17; F (9,60) = 503.8, p < 0.001). There was an average measurement error across the four traits of 7.4%, broadly comparable with studies employing advanced photogrammetric methods to measure antler traits (e.g., [54,55]). We then tested for directional asymmetry using paired t-tests and results indicated that three measurements taken showed FA (brow tine length: t = −0.78, p = 0.44; beam circumference: t = −1.27, p = 0.44; curved antler length: t = 1.38, p = 0.17), and one measurement, coronet circumference, showed directional asymmetry (t = 2.48, p = 0.02; mean right/left = 184.8 mm/183.2 mm).…”

Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs

“…Many centrosaurines exhibit asymmetry from side to side in epiparietal number and morphology, similar to the differences in cervids ( Ditchkoff & deFreese, 2010 ) and specifically caribou ( Miller, 1986 ). The extreme asymmetry is ep1 and ep2 in Lokiceratops is unusually pronounced when compared to other centrosaurines such as Coronoceratops brinkmani , Centrosaurus, Styracosaurus albertensis , Einiosaurus procurvicornis , and Pachyrhinosaurus lakustai .…”

No Difference in Antler Asymmetries Between Two Captive Maral Deer Populations

“…As, according to our results, size was unrelated to symmetry, it could be expected that the cost of larger ornamentation would create developmental stress for their owners, heavier individuals not being the only ones capable of bearing the handicap of growing large traits or symmetries. If sexual characters, like antlers, are costly to produce (Ditchkoff & deFreese, 2010) the relative cost to produce equal-sized traits would be the same for lighter weight individuals. This might not be the case in wild animals, but can be explained in this research by the fact that the studied animals are bred in an artificial environment, so those costs may be perfectly covered.…”