Biometric analysis applied to three age classes of roe deer (Capreolus capreolus) in a population of central Italy

Roe deer are often used as bioindicators; however, little is known about the potential relationship between biometric parameters and the different phenological developmental phases of males compared to females. This study focuses on the analysis of biometric data of three age groups (juveniles, subadults and adults) of the roe deer population, performed on samples collected during the period 2017-2023. The aim is to evaluate the relationship between body/cranial parameters and sex-specific developmental phases, both to create a database and to provide morphological information useful for deepening the knowledge about the roe deer population and for planning management actions, including selective hunting. Eight cranial linear distances were measured to the nearest 0.05 mm with calipers on the cranium of the roe deer, and four body linear distances were measured to the nearest 1 cm with flexible measuring devices. Data were analysed using ANOVA. Multivariate size-constrained factorial analysis was applied to investigate both shape changes and the shape morphology of the cranium for each age-sex group. Analysis revealed weak sexual dimorphism; significant differences emerged in head-trunk length, height at withers and hock length in adults, while chest circumference remained similar. Cranial measurements showed males develop wider cranium earlier, whereas females exhibit prolonged growth in sensory related structures. Factorial analysis confirmed size as the primary differentiating factor among age classes. Males reach adult morphology faster, while females continue cranial development into the second year. Data underline the importance of age and sex in the morphological development of roe deer and highlight that understanding the relationship between body parameters and developmental stages is essential to refine selective hunting criteria and ensure sustainable population management.