Personalideer: A comprehensive review of personality studies in cervids

Understanding animal personality, that is, consistent behavioural variation among individuals, is essential for elucidating the evolutionary origins of human personality. Despite extensive research on personality in diverse taxa, its significance in deer (i.e. cervids, family Cervidae), a taxon with diverse socioecological strategies, remains largely unexplored. This review summarizes the deer personality literature and highlights the knowledge gap in the studied species, personality assessment methods and traits, the general goal of the study, and implications for human personality research. We identified 32 eligible studies on seven species of deer, representing only a small portion of existing deer taxonomic diversity. More than half of the articles focused on three common deer species, roe deer ( Capreolus capreolus), fallow der ( Dama dama), and elk ( Cervus canadensis). Most studies evaluated reactions to capture, handling, and approaching humans, interpreting these behaviours as ‘Boldness’ or a ‘Coping style’. Also, most articles investigated the personality links to ecological variables, followed by physiological measures, and management applications. We advise researchers to move beyond measuring single traits and adopt a multitrait–multimethod approach, as is common in human personality research. Finally, deer and other animal models might be viable alternatives for studying adaptive value and genetic and environmental underpinnings of personality when research on humans is complicated.