Techniques were developed and validated to measure fecal estrogen and progesterone concentrations of the female cheetah. Fecal samples were collected from seven mature females. Cheetahs were monitored before mating and continued until parturition. Four females had normal pregnancies, one conceived but the pregnancy resulted in spontaneous abortion, one was mated but apparently did not conceive and one was treated with gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) to induce follicular growth and ovulation. Vaginal superficial cells increased with increasing estrogen concentrations. Peak estrogen occurred one day postcopulation. Increases in fecal progesterone concentrations, indicative of ovulation, occurred after copulation and hormonally induced ovulation. For the first time reproductive function can be monitored in the cheetah using noninvasive sample collection. 0 1994 Wiley-Liss, 1nc.

Reports on semen quality of the cheetah (Acinonyx jubutus) indicate that high percentages of abnormal morphs and sperm concentrations, 10 times lower than in domestic cats, are found in all populations. These characteristics are believed to result from unusual genetic homozygosity , hypothesized to have been caused by passage of the species through one or more population bottlenecks during its recent history. In a sample of 12 captive-living males, we found semen characteristics to be equal or inferior to those previously reported for males living in other captive facilities. Ten of these males (83.3%) nevertheless produced pregnancies. Seventeen of 19 pregnancies resulted from matings during a single estrus. This examination of the reproductive potential of males having comparatively inferior ejaculate quality supports the suggestion that husbandry programs may be more significant than physiological impairment in causing the low birth rates of captive cheetahs. These results also have implications for ascertaining fertility thresholds in mammalian populations undergoing increased levels of inbreeding as a consequence of habitat deterioration. 0 1993 Wiley-Liss, Inc.

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Lifetime semen production data provide valuable insight into a species' natural history and biology as well as information about the potential fertility of males at various life stages. An understanding of the ages of sexual maturity, peak sperm production, and gonadal senescence will contribute to the design of species management plans for captive, free-ranging, and reintroduced populations of exotic animals. To describe these life stages in the cheetah, semen was collected biweekly for 13 years from a solitary male beginning at 3 years of age. The 338 ejaculates were obtained noninvasively by artificial vagina. Ejaculate volume and sperm motility score, concentration, and normal morphology were recorded. A sperm quality index incorporating all five semen parameters was calculated to facilitate ejaculate comparisons. Polynomial regression analysis revealed a significant effect of age on volume, which increased throughout the animal's lifetime except for a reduction between ages 10 and 12. Concentration was also significantly affected by age and increased from the age of 3 to the age of 10, then decreased. The sperm quality index revealed a significant effect of age as it increased from age 3 to age 8, then declined as the male grew older. The cheetah did not reach peak semen production until age 8 and continued to produce good quality semen for several more years. These data were somewhat unexpected, given the average cheetah life expectancy of approximately 7 years.

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