title: The role of an alpha animal in changing environmental conditions.
abstract: The maintenance and development of conservation areas by grazing of large herbivores, such as Przewalski's horses, is common practice. Several nature conservation areas house male bachelor groups of this species. When males are needed for breeding they are removed from the groups, often without considering group compositions and individual social positions. However, alpha animals are needed for ensuring group stability and decision making in potentially dangerous situations in several species. To investigate the role of the alpha male in a bachelor group, we observed the behaviour of five Przewalski's horse males during the enlargement of their enclosure. We analyzed the group's social structure and movement orders, as well as the animals' connectedness, activity budgets, and whether they moved with preferred group members and how factors such as social rank influenced the horses' behaviour. We also investigated the excretion of glucocorticoid metabolites (GCM) via faeces of the horses while exploring a new area as a parameter of glucocorticoid production. Our results show that the alpha male is important for a bachelor group in changing environmental conditions. The alpha male had the highest level of connectedness within the group. When exploring the new environment, its position in the group changed from previously being the last to being the first. Furthermore the whole group behaviour changed when exploring the new area. The stallions showed reduced resting behavior, increased feeding and did not stay close to each other. We found that the excretion of glucocorticoid metabolites of most horses rose only marginally during the first days on the new area while only the alpha male showed a significant increased amount of glucocorticoid production during the first day of the enclosure enlargement.
authors.affiliation: University of Regensburg, Biologie 1, Universitätsstraße 31, 93053 Regensburg, Germany; University of Applied Sciences Nuertingen, Faculty Agriculture, Economics and Management, Department Equine Management, Neckarsteige 6-10, 72622 Nuertingen, Germany. Electronic address: Riccarda.Wolter@gmx.de.
authors.forename: Riccarda
authors.initials: R
authors.lastname: Wolter
authors.affiliation: Landschaftspflegeverband Stadt Augsburg e.V., Dr.-Ziegenspeck-Weg 10, 86161 Augsburg, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Pantel
authors.affiliation: Institute of Animal Husbandry and Animal Breeding, University of Hohenheim, Garbenstr. 17, 70593 Stuttgart, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Stefanski
authors.affiliation: Institute of Medical Biochemistry, Department of Biomedical Sciences/Biochemistry, University of Veterinary Medicine, Veterinär-Platz 1, 1210 Vienna, Austria.
authors.forename: Erich
authors.initials: E
authors.lastname: Möstl
authors.affiliation: University of Regensburg, Biologie 1, Universitätsstraße 31, 93053 Regensburg, Germany; University of Applied Sciences Nuertingen, Faculty Agriculture, Economics and Management, Department Equine Management, Neckarsteige 6-10, 72622 Nuertingen, Germany.
authors.forename: Konstanze
authors.initials: K
authors.lastname: Krueger
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology; D005243:Feces; D005247:Feeding Behavior; D005938:Glucocorticoids / Q000378:metabolism; D006736:Horses / Q000502:physiology* / Q000523:psychology*; D008124:Locomotion; D008297:Male; D012146:Rest / Q000502:physiology; D012930:Social Dominance
chemical_list: D005938:Glucocorticoids
keywords: Alpha male; Bachelor group; Equus ferus przewalskii; Group structure; Horse