Social Stress in Wolves

Book chapter in: "Wolves: Biology, Behavior and Conservation" (ed by Ana Paula Maia & Henrique F. Crussi)

Vasconcellos, A.d.S., Ades, C. & Kotrschal, K. (2012): Social Stress in Wolves. In "Wolves: Biology, Behavior and Conservation". Ed by Ana Paula Maia and Henrique F. Crussi. ISBN: 978-1-62100-916-0. NY: Nova Science Publishers (Animal Science, Issues and Professions)

In wild wolf packs social relationships constitute the most important factor influencing the stress levels and welfare. In this review, we summarize factors influencing social stress of wolves, considering different wolf profiles and their relationships with humans. Wolf social relationships are influenced not only by rank order, but also by the affective behaviors individuals display towards other pack members. Cortisol, an important component of the mammalian stress response is found generally in higher levels in dominant wolves than in subordinates in the wild, but cortisol levels are not predictive of rates of agonistic interactions. Social stress in wolves seems thus not to be a consequence of subordination, but a cost of dominance. Higher levels of aggressive interactions are reported from enclosure-kept animals in comparison with wild wolves. Little is known, however, about the behavioral factors mediating the connection between glucocorticoids levels and stress loads in captivity. Some of the data reviewed here indicate higher levels of glucocorticoid in dominants, but similar levels in both dominants and subordinates have also been reported. Stress hormone data from wolves in captivity may be confounded by unnatural group composition, restricted living areas (fences making temporary avoidance impossible), and by the different levels of socialization with humans. As wolves’ behavior is flexible, varying according to environmental and social context, data from captivity may be viewed as indicating the potential range of behaviors wolves can perform in the wild. Hand-raised wolves have been recently used as a model for the study of wolf cognition and the origins of dog behavior. This study has brought insights into the role human partners may have in modulating wolves’ stress levels. A wide field for further research opens, which may shed light on the adaptive flexibility of wolves, and may contribute to improve wolf welfare in captivity and in the wild.