The impact of age-class and social context on fecal glucocorticoid metabolite levels in free-ranging male giraffes

Show simple item record Wolf, T.E. (Tanja) Bennett, Nigel C., 1961- Burroughs, R.E.J. (Richard) Ganswindt, Andre 2017-12-04T06:44:22Z 2018-01
dc.description.abstract One of the primary sources of perceived stress is the social environment of an animal and the interactions with conspecifics. An essential component of the response to a stressor is the activation of the hypothalamic–pituitary–adrenocortical axis, which results amongst others in a temporal increase in circulating glucocorticoid (GC) levels. Giraffes occur in a highly flexible fission-fusion social system and group compositions can change on a daily basis, with bulls establishing an age-related dominance hierarchy and showing a roaming strategy in the search for fertile females. The aim of this study was to non-invasively monitor the influence of different group compositions (mixed sex groups vs. all-male groups) on GC concentrations in free ranging giraffe bulls of different age classes. We collected fecal samples from free-ranging giraffe bulls for 12 months in a South African Private Game Reserve to examine age- and social context-related patterns of fecal GC metabolite (fGCM) concentrations. We found that fGCM levels in giraffe bulls are age-class dependent, as well as associated with changes in the social environment. Independently of the social setting, bulls of the youngest age class exhibited the highest fGCM levels compared to bulls of the other two older age-classes, with differences most pronounced when the bulls are associated in all-male groups. In contrast, an almost reversed picture appears when looking at the fGCM levels of sexually active individuals in mixed sex groups, where highest levels were found for the bulls in the oldest age-class, and the lowest for the bulls in the youngest age-class. The study stresses the importance to taking factors such as age-related status and social settings into account, when interpreting fGCM levels in free ranging giraffes. en_ZA
dc.description.department Anatomy and Physiology en_ZA
dc.description.department Centre for Wildlife Management en_ZA
dc.description.department Mammal Research Institute en_ZA
dc.description.department Zoology and Entomology en_ZA
dc.description.embargo 2019-01-01
dc.description.librarian hj2017 en_ZA
dc.description.sponsorship The National Research Foundation, South Africa; a postgraduate bursary from the DST-NRF SARChI chair for Mammal behavioural ecology and physiology to (NCB); Novartis/South African Veterinary Foundation Wildlife Research Fund. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Wolf, T.E., Bennett, N.C., Burroughs, R. & Ganswindt, A. 2017, 'The impact of age-class and social context on fecal glucocorticoid metabolite levels in free-ranging male giraffes', General and Comparative Endocrinology, vol. 255, pp. 26-31. en_ZA
dc.identifier.issn 0016-6480 (print)
dc.identifier.issn 1095-6840 (online)
dc.identifier.other 10.1016/j.ygcen.2017.09.022
dc.language.iso en en_ZA
dc.publisher Elsevier en_ZA
dc.rights © 2017 Elsevier Inc. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in General and Comparative Endocrinology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in General and Comparative Endocrinology, vol. 255, pp. 26-31, 2018. doi : 10.1016/j.ygcen.2017.09.022. en_ZA
dc.subject Glucocorticoid (GC) en_ZA
dc.subject Fecal glucocorticoid metabolite (fGCM) en_ZA
dc.subject Giraffe bulls en_ZA
dc.subject Stress en_ZA
dc.subject Non-invasive hormone monitoring en_ZA
dc.subject Feces en_ZA
dc.subject South Africa (SA) en_ZA
dc.title The impact of age-class and social context on fecal glucocorticoid metabolite levels in free-ranging male giraffes en_ZA
dc.type Postprint Article en_ZA

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