Thesis

The knowledge of the reproductive biology of the roan antelope (Hippotragus equinus) is crucial to improve management practices in conservation breeding programmes for this species. In this study, I studied the reproductive behaviours of male and female roan antelope in captivity and determined the respective endocrine correlates and the stress-related hormone patterns in both sexes. Fifteen pre-defined sexual behaviours are exhibited by males, with the precopulatory behaviours being prominent. In females, receptivity lasts up to 72 h and eight pre-defined oestrus-related sexual behaviours are usually exhibited, with homosexual mounts being observed prior to oestrus for the first time for this species, and in the tribe Hippotragini. In male roan antelope, faecal androgen metabolite (fAM) concentrations increased during the breeding periods and were low during the non-breeding periods. Breeding males showed a 73% increase in fAM concentrations during the breeding period compared to the non-breeding periods, and those were 85% higher when compared to the lactation/gestation periods. Results also revealed that fAM production in male roan antelope increase with reducing daylight duration but is not influenced by ecological seasons. These endocrine changes in males followed the same pattern as the frequencies of sexual behaviours observed. In females, faecal progestagen metabolite (fPM) and faecal oestrogen metabolite (fEM) analyses, revealed oestrous cycle length of between 16 to 37 days in multiparous females, 16 days in pluriparous females, and 37 days in nulliparous females, with the length of luteal and follicular phases of between 14.0 ± 0.7 days and 16.0 ± 2.4 days in multiparous females, 17.1 ± 1.1 and 16.8 ± 2.3 in nulliparous females and 9.0 days and 6.0 days for the nulliparous female. Results further showed that the length of gestation is approximately 280.4 ± 4.8 days and the longitudinal profile of fPM levels showed a significant increase from three months post-conception persisting until parturition. Findings of this study revealed that in female roan antelope, the resumption of the ovarian activity may occur between 16 to 62 days after parturition. Results demonstrated that a 11-oxoaeticholanolone I enzyme immunoassay (EIA) detecting 11,17 dioxoandrostanes is an adequate EIA to use when quantifying faecal glucocorticoids metabolite (fGCM) in the roan antelope. In males, fGCM concentrations increased by 80 % during active reproductive periods compared to respective concentrations for the non-active reproductive periods. In females, fGCM levels did not vary significantly between the phases of the oestrous cycle, however, a slight increase above baseline was noted prior to ovulation. During the gestation period, fGCM concentrations were significantly high compared to respective levels during the lactation and mating periods. Both males and females showed higher fGCM concentrations during the dry season compared to the wet season. However, fGCM concentrations were not correlated with rainfall and temperature. The detailed description of the reproductive behaviours and respective correlates along with the newly developed non-invasive methods for monitoring reproductive and stress-related hormones has provided new insights into the reproductive biology of the roan antelope which can be used to assist management decisions in breeding programmes for this iconic antelope.Thesis (PhD (Zoology))--University of Pretoria, 2021.DST-NRF SARChI chair for Mammal Behavioural Ecology and Physiology , Gun 46756Zoology and EntomologyPhD (Zoology)Unrestricte