Stress hormone level and the welfare of captive European bison (Bison bonasus): the effects of visitor pressure and the social structure of herds

Abstract

Background Captive European bison (Bison bonasus) play an active role in conservation measures for this species; this includes education, which may conflict with these animals’ welfare. The effect of the presence of visitors on the welfare of captive animals can be negative, positive or neutral. However, the response of a given species to visitors is difficult to predict, since even closely related species display varying levels of tolerance to captivity. The aim of the study was to compare immunoreactive fecal cortisol levels (regarded as an indicator of the level of physiological stress) in groups of captive European bison that differed in terms of their social structure and the level of visitor pressure. The second aim was to determine if there was a correlation between intestinal parasitic burden and immunoreactive fecal cortisol levels. Results Immunoreactive fecal cortisol levels were not influenced by sex or age. However, study site and the interaction between study site and visitor pressure were statistically significant. European bison in one enclosure presented higher levels of immunoreactive fecal cortisol on weekdays than at weekends. In the other two study sites, the levels did not differ between weekdays and weekends. No correlation was found between parasitological infestation and immunoreactive fecal cortisol levels. Conclusions Measurement of fecal cortisol metabolites could be a valuable method for further research into the welfare of European bison in captivity. More subtle factors such as individual animal characteristics, feeding systems, and the arrangement of enclosures can be of great importance in terms of the effect of visitors on animals. The results of this study can be used in guidelines for the management of European bison populations.

Comparing Space Use and Fecal Glucocorticoid Concentrations during and after the COVID-19 Closure to Investigate Visitor Effects in Multiple Species

“…Our results are inconsistent with previous research in other bovid ungulates such as Indian blackbuck (Antelope cervicapra) [56] and Indian gaur (Bos gaurus gaurus) [8], which showed increased activity and aggression and decreased resting in response to visitors. Alternatively, at two zoos, bison (Bison bonasus) showed no difference in fecal glucocorticoids between weekdays and weekends, as we observed in this banteng herd, and bison at another zoo had lower glucocorticoid levels on weekends than on weekdays [57], suggesting a neutral or even positive impact of visitors, depending on the herd. Although little has been published on banteng in zoos, they have been described as resilient and not timid [58][59][60], suggesting banteng may thrive in the zoo environment, especially if they find visitors positively stimulating.…”

The Benefit of Enrichment Application on Animals in Captivity

“…Plugging the feathers, biting the tails, showing repetitive movements, eating their own feces, and being aggressive [1][4]. Enclosures are not provide enrichment environment as similar in nature [16] Animals cannot express natural behavior as normal behavior [19] Provision sleeping space in winter for bear, tress for arboreal living for orangutan, large size enclosure for group social of birds [9] The weather differ with the habitat Changes weather affect the weight and energy consumption [21] Changes on breeding season [7] Animals loss of weight or gained [1] Changes in reproductive cycle hormone secretion [22] Variety of feeding enrichment: browsing, puzzle, scatter [3] Providing substrate, tress, litter, grass, scent [2] No specific breeding behaviors needs Lacking of natural and or wild behavior developed in captive; Human interference [7] loss of genetic diversity, mutations, in-breeding, and decrease in reproduction [22] Social integration or breeding stimulation [19] Modified subtle factors based on individual animal characteristics [5] Social ecology/species composition Solitary, social or hierarchy group [22] Improper the size of enclosure [12] Less reaction from animals and inconsistent reaction [12] Small cages or area for social and group animals [12] Increase interaction of anticipatory behavior by human-animals interaction between keeper and animals [17] Developed structural change and improvement the enclosure [11]…”

“…Nutritional deficit [2] Repetitive diets [12] inhibit sexual development and physiological process [5] may not provide sufficient mental or physical stimulation [2] Provide browsing and proper nutrition [18] Increase exercise or fitness [17] It's not just the behavior that will changes, but the symptoms of the diseases will arise. For the examples skin problems, it because when the animals are licking and plugging their fur.…”

Glucocorticoids of European Bison in Relation to Their Status: Age, Dominance, Social Centrality and Leadership

“…Indeed, the species is listed as a threatened species on the IUCN Red List and requires especially high attention in conservation and rewilding proceedings [ 13 , 97 , 98 , 99 ]. Measurement of faecal glucocorticoid metabolites, associated with other parameters and particularly in response to stressors, could thus be a valuable tool to follow and improve the adaptation and the welfare of herds in the semi-wild and in captivity [ 39 ]. This new knowledge could, for instance, allow us to take into account the importance of older females as group members as being stable and reassuring figures during captures, veterinary interventions or new reintroductions [ 13 , 38 ].…”

“…We focused our study on semi free-roaming European bison ( Bison bonasus , L. 1758), a wild ungulate living in groups with an average of 20 individuals [ 37 , 38 ]. The only study reporting the interaction between glucocorticoid concentrations, individual characteristics and social structure in European bison was performed on captive herds and showed that glucocorticoid concentrations were not influenced by sex or age [ 39 ]. On the basis of behavioural observations made on leadership and sociality in this species [ 40 , 41 , 42 ] and the literature on the subject, we made the following hypothesis: the oldest females in the herd, which are the preferential leaders and the more dominant and central individuals, should have a lower average rate of FGM compared to the other group members.…”