The present study investigated the seasonal behavioral patterns of European bison (Bison bonasus) maintained under semi-liberty conditions in the Hațeg–Slivuț Reserve, Romania. Ethological observations were conducted throughout all four seasons in order to evaluate the daily activity budget and the main categories of behavior, including feeding, resting, exploration, social interactions, reproductive behavior, and agonistic activities. Behavioral observations were organized into seasonal ethograms that reflected the temporal distribution of activities during a 24-hour cycle. The results demonstrated significant seasonal variation in behavioral expression. During spring, summer, and autumn, European bison exhibited two major feeding peaks, occurring in the early morning and late afternoon, while midday periods were predominantly associated with resting and rumination behaviors. In contrast, winter activity patterns were characterized by reduced locomotor activity, prolonged resting periods, and concentration of feeding behavior around supplementary feeding sites. Feeding behavior also varied seasonally according to vegetation availability. Fresh grasses, shoots, and herbaceous plants dominated the diet during spring and summer, whereas bark, twigs, dry plant material, and supplementary fodder became increasingly important during autumn and winter. Social interactions were more frequent during the breeding season, particularly among males, where agonistic displays contributed to hierarchy establishment and reproductive competition. Grooming and reciprocal licking behaviors were also observed, emphasizing the importance of social cohesion within the herd. Overall, the observed behavioral repertoire corresponded closely with reference ethograms described in the scientific literature for free-ranging European bison populations. The study highlights the adaptive behavioral flexibility of Bison bonasus under semi-liberty management conditions and supports the importance of ethological monitoring for conservation and welfare assessment programs.

European bison; Bison bonasus; ethology; seasonal behavior; feeding behavior; semi-liberty conditions

biology

Presentation: poster