Inter-birth interval in zebras is longer following the birth of male foals than after female foals
2012
Barnier, Florian | Grange, Sophie | Ganswindt, Andre | Ncube, Hlengisizwe | Duncan, Patrick | Centre d'Études Biologiques de Chizé (CEBC) ; Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS) | Mammal Research Institute ; Department of Zoology and Entomology [Pretoria] ; University of Pretoria [South Africa]-University of Pretoria [South Africa] | Department of Production Animal Studies ; University of Pretoria [South Africa] | Forest Resources and Wildlife Management [Bulawayo] ; National University of Science and Technology [Bulawayo]
International audience
显示更多 [+] 显示较少 [-]英语. Mammalian reproductive rates vary among individuals for physiological and environmental reasons. This study aims to determine reproductive rates from an individually monitored population of wild Plains zebras Equus quagga, and to assess the sources of variability in inter-birth intervals. The animals were monitored, where possible, every six months from 2004 to 2011. Thirty nine intervals corresponding to 65 births in 26 mares were identified, using direct observations and faecal steroid monitoring. Mean foaling rate of the population is 0.74 foal/year, and comparable with the literature. There was no significant effect of mother's age, nor of the season of previous birth on the length of inter-birth intervals. Inter-birth interval was significantly longer when the first foal was a male. This finding indicates that additional costs of having a son may delay future reproduction and thus reduce the total number of offspring a mare can have during her lifetime. Individually-based data provide critical information on the determinants of reproductive rates, and are therefore a key to understanding the causes of variations in life-history traits.
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