Blanvillain C. 1998. Contribution à la compréhension de la stratégie de reproduction de l'oryx d'Arabie (Oryx leucoryx) face aux conditions désertiques: application la conservation de l'espèce [Study of the reproductive strategy of the Arabian oryx face to its desert-living habitat and application to conservation]. Thèse de Doctorat [Doctor of Philosophy Thesis], Paris, Muséum National d'Histoire Naturelle. 128 pp. [French text]

Summary: Little is known about the reproductive strategy of the Arabian oryx, a species endemic to the Arabian Peninsula deserts. Paradoxically exterminated in the wild and saved from extermination by man, this species is a symbol for conservation, while 64 of the remaining 137 species of bovids are actually on the verge of extinction. The bibliographic part of this thesis presents this situation, the adaptations developed by ungulates in a desert, the reproductive strategies of ungulates according their habitat and social organisation, and the available knowledge on reproduction in Hippotraginae. The second part presents the methods: the reproduction of the Arabian oryx was studied through: (1) the assay of plasmatic steroids and of LH, then the assay of faecal steroid metabolites, in animals maintained at the NWRC and in the Mahazat as-Sayd reserve, and (2) the analysis of the studbook data. The results obtained are presented and discussed in a third part and include: the establishment of a cycle length of 23.7 ± 1.3 days and of a gestation length of 255.2 ± 1.5 days; a post-part anoestrus duration of 18 or 30 days respectively in females in contact or not with a male; an onset of puberty occurring around the thirteenth or the seventeen months respectively in females kept with or without male contact; an onset of puberty in male occurring between the sixth and seventh months of life while the thirteen month correspond to the apparition of testosterone peaks which occurred over a period of 24.1 ± 1.6 days, coinciding with the oestrous cycle length of the female; the successful utilisation of faecal progesterone metabolite assay for monitor the reproduction in this species; the existence of birth peaks in 8 on 13 institutions retained in the study of the studbook, and the relation between births and low temperatures, conceptions and long day-length, in a majority of institutions. The general conclusion and perspectives are presented in a last part.

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