Management of intraspecific aggression in two bull giraffes (Giraffa camelopardalis ssp. rothschildi)
Affiliation
University of Chester; University Centre Reaseheath; Knowsley SafariPublication Date
2024-05-29
Metadata
Show full item recordAbstract
Maintaining non-breeding individuals in zoological collections may sometimes necessitate housing bachelor groups. In turn, intact cohabiting males may express increased intraspecific agonistic behaviors and management intervention may be indicated. Where castration is deemed inappropriate (e.g., future breeding, or anesthesia and surgery-related risk), the immune-contraceptive gonadotrophin-releasing hormone (GnRH) is increasingly used as an alternative. When intraspecific aggression (sparring) in two bull giraffes housed as a bachelor pair at Knowsley Safari, UK, escalated in frequency and intensity (despite management interventions), further mediation was warranted to moderate sparring behaviors. The EEP recommendation was for one giraffe, the (slightly) older, outwardly mature (darker, strong musth) individual, to be treated with the GnRH vaccine Improvac® (Zoetis, USA). To gauge the efficacy of vaccination, behavioral observations were conducted during each vaccination Phase to identify changes in the frequency of sparring behaviors. In addition, fecal samples were collected by keepers and sent to Chester Zoo's Endocrine Diagnostic Laboratory for analysis to compare androgen levels between the pre- and post-vaccination Phases. Testicular atrophy was investigated using both visual inspection and photographic images. The GnRH vaccine Improvac® initially appeared to be associated with reduced aggressive behaviors in the two bull giraffes. Sparring behaviors decreased in frequency after each vaccination Phase, although these did not significantly diminish until Phase 4. Physiological markers were inconclusive as testosterone concentrations varied throughout the Phases, although levels remained low after the fourth vaccination Phase. Approximately eight months following the initial vaccination with Improvac®, the unvaccinated bull exhibited heightened aggression, resulting in physical aggression and injury to the vaccinated bull. As a result, both bulls are now on an Improvac® vaccination schedule which has enabled them to remain housed together as a bachelor pair.Citation
Harley J., Tracey, R., Stanley, C. R. & Banks, L. (2024). Management of intraspecific aggression in two bull giraffes (Giraffa camelopardalis ssp. rothschildi). Zoo Biology, 43(4), 383-390. https://doi.org/10.1002/zoo.21843Publisher
WileyJournal
Zoo BiologyAdditional Links
https://onlinelibrary.wiley.com/journal/10982361Type
ArticleISSN
0733-3188EISSN
1098-2361Sponsors
unfundedae974a485f413a2113503eed53cd6c53
10.1002/zoo.21843
Scopus Count
Collections
The following license files are associated with this item:
- Creative Commons
Except where otherwise noted, this item's license is described as Attribution-ShareAlike 4.0 International