Is being with girls stressful? Social environment influences hormone levels in male giraffes

Show simple item record Wolf, T.E. Bennett, Nigel C., 1961- Burroughs, R.E.J. (Richard) Ganswindt, Andre
dc.contributor.other University of Pretoria. Faculty of Veterinary Science 2017-07-14T07:57:21Z 2017-07-14T07:57:21Z 2016-07-29 2016-08-25
dc.description Poster presented at the University of Pretoria, Faculty of Veterinary Science Faculty Day, August 25, 2016, Pretoria, South Africa. en_ZA
dc.description.abstract Giraffes (Giraffa camelopardalis giraffa) live in a fission-fusion social system, characterized by the splitting and reunion of subgroups within a larger social network. Adult bulls show a roaming tactic to search for fertile females, whereas younger bulls are often seen in all male groups. In this study we combined behavioural observations with hormonal data. Therefore, a giraffe population of about 80 individuals (11 adult males, 28 adult females, and 32 juvenile / sub-adult animals) was monitored six days a week from dawn to dusk for a period of 12 months (Nov 2014–Oct 2015). Giraffes were individually identified by their unique pelage pattern and adult bulls assigned to age classes based on their appearance (A, B, and C), with class A bulls being the oldest and tallest. A total of 790 faecal samples were collected and analysed for faecal androgen (fAM) and glucocorticoid metabolite (fGCM) concentrations. Class A bulls show significantly higher fAM levels compared to younger bulls, with lowest fAM levels found for the juvenile / sub-adult group. Longer periods of increased fAM levels in the oldest bulls mainly occur during summer and are associated with an observed birthing peak. Within class A, fAM levels of bulls in all male groups are significantly lower than when associated with females, however, these levels are still significantly higher compared to respective fAM levels from youngest males. No significant differences in overall fGCM levels could be found between the different age classes. However, within class A the bulls show a trend for higher fGCM levels when sexually active compared to when associated with an all-male group. In contrast, juvenile / sub-adult bulls show highest fGM levels when they are in all-male groups, which is possibly linked to intrasexual competition as younger bulls still need to establish their position within the hierarchy. en_ZA
dc.description.librarian ab2017 en_ZA
dc.format.extent 1 poster : color photos, graphs en_ZA
dc.format.medium PDF file en_ZA
dc.language.iso en en_ZA
dc.publisher Pretoria : University of Pretoria, Faculty of Veterinary Science en_ZA
dc.relation.ispartofseries Veterinary Science Faculty Day posters 2016 en_ZA
dc.relation.requires Abode Acrobat reader en_ZA
dc.rights ©2017 University of Pretoria. Faculty of Veterinary Science (Original and digital). Provided for educational purposes only. It may not be downloaded, reproduced, or distributed in any format without written permission of the original copyright holder. Any attempt to circumvent the access controls placed on this file is a violation of copyright laws and is subject to criminal prosecution. Please contact the collection administrator for copyright issues. en_ZA
dc.subject Hormone levels en_ZA
dc.subject Male giraffes en_ZA
dc.subject Giraffe (Giraffa camelopardalis) en_ZA
dc.subject.lcsh Veterinary medicine -- Posters en_ZA
dc.subject.lcsh Giraffe -- Endocrinology en_ZA
dc.subject.lcsh Hormones en_ZA
dc.subject.lcsh Veterinary endocrinology en_ZA
dc.subject.lcsh Glucocorticoids en_ZA
dc.subject.lcsh Androgens en_ZA
dc.title Is being with girls stressful? Social environment influences hormone levels in male giraffes en_ZA
dc.type Presentation en_ZA
dc.type Text en_ZA

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