Methods for estimating the age of roe deer (Capreolus capreolus): a review

Accurate age estimation is essential for understanding roe deer ( Capreolus capreolus ) population dynamics and implementing effective wildlife management. This review systematically evaluates existing age estimation methods, categorizing them into tooth-based approaches (cementum and dentin incremental lines, tooth metrics, occlusal surface morphology, dental development), non-tooth-based methods (bone fusion status, eye lens weight, pedicle morphometry), molecular techniques (epigenetic clocks), and combined criteria. Validation studies using marked individuals reveal considerable discrepancies between methodological prevalence and actual accuracy. Cementum annuli analysis, often regarded as the reference standard, achieves only 46% accuracy in the largest direct validation. Dental development provides monthly precision but is limited to individuals under 15 months. Occlusal surface wear assessment, the most widely applied field method, shows high accuracy for young animals but declines markedly beyond 24 months. Eye lens weight and pedicle morphometry exhibit curvilinear relationships with age, losing precision after four years. Epigenetic clocks demonstrate superior accuracy (mean absolute difference ± 0.558 years) but require blood sampling and incur higher costs. Combined morphological criteria achieve 68–82% accuracy for animals up to three years. No single method satisfies all requirements of accuracy, practicality, cost-effectiveness, and applicability to live animals. Individual methods should be considered complementary rather than exclusive, with the choice of method depending on the research objectives, available resources, and the condition of the study material. Future research priorities include validating epigenetic clocks across populations, developing non-invasive techniques such as dental radiographic pulp measurements, and establishing standardized protocols using marked individuals of known age.