Age Determination and Life History Traits in Ungulates

Ungulates exhibit diverse life history strategies that shape their growth, reproductive output and longevity. Accurate age determination underpins the study of cohort dynamics, population structure and individual fitness. Traditional approaches have focused on dental morphology, including tooth eruption sequences, wear patterns and analysis of cementum annuli. These methods are minimally invasive, suitable for both living animals and skeletal remains, and widely applied in wildlife management, palaeontology and zooarchaeology. Recent advances in molecular techniques, notably the use of epigenetic clocks based on DNA methylation, complement morphological methods by distinguishing biological ageing from chronological age. By integrating age data with measures of sex-specific trait development—such as antler growth in cervids, rates of tooth wear and indicators of body condition—researchers reconstruct key life history traits including age at first reproduction, senescence trajectories and trade-offs between growth and longevity. This interdisciplinary framework informs conservation strategies, refines sustainable harvest models and deepens our understanding of how environmental pressures influence ungulate demographics across varied ecosystems.

Research from Nature Portfolio

Recent studies have elucidated how social environment and intra-sexual competition drive allocation of resources between secondary sexual traits and somatic maintenance. In male red deer, populations characterised by high levels of male–male rivalry develop larger antlers, yet experience accelerated tooth wear and reduced potential lifespan. Controlled experiments in captive enclosures confirmed that exposure to rivals during antler growth triggers increased investment in antler size at the expense of dental durability. These findings demonstrate adaptive plasticity in energy allocation, reveal a direct link between trait expression and longevity, and highlight the value of combining behavioural manipulations with dental ageing methods to interpret fitness trade-offs in wild ungulate populations.

Age Determination and Life History Traits in Ungulates publication trend

The graph below shows the total number of articles in age determination and life history traits in ungulates across all publications each year (not limited to Nature Index journals).

Technical terms

Cementum annuli: successive layers of mineralised tissue deposited annually in tooth cementum, counted to determine chronological age.

Tooth eruption: the sequential emergence of teeth through the gums, used as an indicator of juvenile age classes.

Tooth wear: progressive abrasion and attrition of dental surfaces over an individual’s lifespan, reflecting both age and dietary habits.

Epigenetic clock: a statistical model predicting biological age from DNA methylation patterns, offering molecular estimates of ageing rate.

Life history traits: the timing and quantity of key events in an organism’s lifetime, including growth, reproduction and senescence.

References

1. Designing Epigenetic Clocks for Wildlife Research. Molecular Ecology Resources (2025).
2. Social environment modulates investment in sex trait versus lifespan: red deer produce bigger antlers when facing more rivalry. Scientific Reports (2020).
3. Assessing current visual tooth wear age estimation methods for Rangifer tarandus using a known age sample from Canada. PLOS ONE (2024).
4. An improved age estimation method for caribou and reindeer using tooth eruption and wear. Journal of Archaeological Science (2025).