Department of Biology, University of Chicago, Chicago, and Institute of Primate Research, National Museums of Kenya, Nairobi.
Department of Biology, University of Missouri-Columbia.
Am J Primatol. 1985;8(2):113-125. doi: 10.1002/ajp.1350080204.
Repeated censuses of a population of yellow baboons (Papio cynocephalus) in Amboseli National Park, Kenya, revealed a decrease from over 2,500 animals in 1963-1964 to 123 individuals in 1979, or from a density of about 73 to 1.8 baboons per km over a 15-year period. Median group size decreased from 43 in 1964 to 27 in 1979. The largest and smallest groups declined the most; groups near the median have maintained fairly stable size and age distributions. The population seemed to have stabilized by 1983 at approximately 150 animals in six groups (median group size 28; density 2.2/km). Although baboon population and group size appeared to be stable during 1963-1964, the age distribution and demographic parameters (age-specific mortality and natality for one social group) during that year indicate that the population decline had already started. The rate of population decline was greatest in the 1964-1969 period and remained appreciable during the next 5 years. The decline of the baboon population was paralleled by that of other Amboseli savannah woodland mammalian species and took place during a period of very high mortality of fever trees (Acacia xanthophloea) and extensive invasion of the area by halophytes, a transition brought on by rising ground water and consequent elevation of the soil salinity zone. In this and several other primate populations, mortality of infants and juveniles appears to be the demographic variable most sensitive to environmental change.
肯尼亚安博塞利国家公园的黄狒狒（Papio cynocephalus）种群进行了多次普查，结果显示，该种群数量从 1963 年至 1964 年的超过 2500 只减少到 1979 年的 123 只，即在 15 年期间，密度从每平方公里约 73 只减少到 1.8 只。中位数群体规模从 1964 年的 43 只减少到 1979 年的 27 只。最大和最小的群体下降幅度最大；中位数附近的群体保持了相当稳定的规模和年龄分布。到 1983 年，该种群似乎已稳定在 6 个群体的约 150 只（中位数群体规模为 28；密度为 2.2/km）。尽管黄狒狒的种群和群体规模在 1963 年至 1964 年期间似乎稳定，但当年的年龄分布和人口参数（一个社会群体的特定年龄死亡率和出生率）表明，种群下降已经开始。1964 年至 1969 年期间种群下降速度最快，在接下来的 5 年中仍保持相当高的水平。黄狒狒种群的下降与安博塞利热带稀树草原林地的其他哺乳动物物种的下降相吻合，并且发生在 fever 树（Acacia xanthophloea）死亡率非常高和该地区广泛被盐生植物入侵的时期，这是地下水上升和土壤盐渍区抬升带来的转变。在这一物种和其他几个灵长类动物种群中，婴儿和青少年的死亡率似乎是对环境变化最敏感的人口变量。
