Existing theories do not explain sex ratio variation at birth in monomorphic roe deer (Capreolus capreolus).

The phenomenon of skewed sex ratios at birth has been reported in many ungulate species. So far, no consistent trend has emerged for roe deer (Capreolus capreolus), because male-biased, female-biased and equal sex ratios at birth have all been found. Nevertheless, both the Trivers-Willard hypothesis and the theory of local resource competition have gained support.

Asymmetry in antler size in roe deer (Capreolus capreolus ): an index of individual and population conditions.

Fluctuating asymmetry (FA) refers to small random differences that occur between the right and the left sides of bilateral characters. Under the hypothesis that the degree of FA in secondary sex traits reflects the ability of males to cope with environmental stress, and consequently reflects individual quality, a negative relationship is expected between FA and the trait size. Additionally, selective mortality acting preferentially on individuals in poor condition, presumably more asymmetric, should lead to a decrease in FA with age.