Data from: Assessing the accuracy of field-based versus laboratory methods for determining the age of roe deer

Accurate age determination in roe deer (Capreolus capreolus L.) is
essential for selective harvesting and informed population management, yet
field-based methods widely used by hunters remain imprecise. This study
compared field-based and laboratory age determination methods in 204
harvested roe deer, categorized by sex and habitat type (forest vs. open
field). Age was estimated using (i) field indicators based on tooth wear
and cranial traits, and (ii) laboratory methods including second molar
height, dry eye lens weight, and cementum annuli counts. Generalized
Linear Models and ANOVA revealed that dry eye-lens weight increased
monotonically with age (η² = 0.885; p < 0.001), showing strong
predictive capacity for cementum-derived age. In contrast, second molar
height exhibited a hump-shaped pattern, with weaker explanatory power. Sex
and habitat type had no significant effects on morphometric traits
associated with age, indicating that temporal biological processes
dominate over ecological or sexual dimorphism. Agreement between
laboratory cementum annuli and field age classifications was fair to
moderate (Cohen’s κ = 0.371 ± 0.039 SE, p < 0.001), whereas the
laboratory cementum annuli and dry eye-lens weight showed moderate
agreement beyond chance (Cohen’s κ = 0.285 ± 0.036 SE, p < 0.001).
These findings demonstrate that while cementum annuli analysis and dry
eye‑lens weight provide robust biological age proxies, field-based methods
currently lack sufficient precision for reliable selective harvest
decisions. Reliable age estimation techniques are essential not only for
effective population management but also for maintaining the biological
and socio-cultural integrity of selective hunting practices.