EN
Fluctuating asymmetry in 30 bilateral cranial non-metric traits was investigated in three roe deer Capreolus capreolus (Linnaeus, 1758) populations living in different habitats in Poland. For each sample, the mean proportion of asymmetric traits per individual {FAnm) was calculated and used for comparisons among populations. The highest value of FAnm (0.18) was displayed by roe deer belonging to the 'field ecotype', a lower one by roe deer belonging to the 'forest ecotype' (0.14), and the lowest (0.12) in a 'transient' population. In contrast to the 'forest' roe deer and the 'transient' population, a gradual and statistically significant decrease of FANM-values over the last 30 years was recorded in the 'field ecotype'. There the proportion of asymmetric traits was also significantly higher in juveniles than in other age classes. Fluctuating asymmetry in roe deer is discussed with regard to the environmental stress hypothesis and the gradual development of a coadapted gene pool in the 'field ecotype'.