Robbins Martha M, Bermejo Magdelena, Cipolletta Chloé, Magliocca Florence, Parnell Richard J, Stokes Emma
Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Am J Primatol. 2004 Oct;64(2):145-59. doi: 10.1002/ajp.20069.
Life-history traits and ecological conditions have an important influence on primate social systems. Most of what we know about the life-history patterns and social structure of gorillas comes from studies of eastern gorillas (Gorilla beringei sp.), which live under dramatically different ecological conditions compared to western gorillas (Gorilla gorilla sp.). In this paper we present new data on western gorilla social structure and life histories from four study sites, and make comparisons with eastern gorilla populations. Data were obtained from two study sites with gorilla groups undergoing the habituation process (Lossi, Democratic Republic of Congo and Bai Hokou, Central African Republic) and two "bai" studies (Maya Nord and Mbeli Bai, Republic of Congo). The size and structure of these groups were similar to those seen in eastern gorillas. However, differences in the occurrence of various group transitions (group formations, changes between one-male and multimale composition, and group disintegrations) exist, and western gorillas notably exhibit much higher rates of male emigration and correspondingly fewer multimale groups compared to mountain gorillas. Certain phenomena have been observed only rarely, including predation by leopards. The preliminary data show no significant differences in birth rates between western gorillas and mountain gorillas. The ecological variability across gorilla habitats likely explains the flexibility in the social system of gorillas, but we need more information on the social relationships and ecology of western gorillas to elucidate the causes for the similarities and differences between western and eastern gorillas on the levels of individuals, social groups, and population dynamics.
生活史特征和生态条件对灵长类动物的社会系统有着重要影响。我们对大猩猩生活史模式和社会结构的了解大多来自对东部大猩猩（山地大猩猩亚种）的研究，与西部大猩猩（西部大猩猩亚种）相比，它们生活在截然不同的生态条件下。在本文中，我们展示了来自四个研究地点的关于西部大猩猩社会结构和生活史的新数据，并与东部大猩猩种群进行了比较。数据来自两个大猩猩群体正在经历习惯化过程的研究地点（刚果民主共和国的洛西和中非共和国的白河口）以及两项“白滩”研究（刚果共和国的玛雅诺德和姆贝利白滩）。这些群体的规模和结构与东部大猩猩相似。然而，在各种群体转变（群体形成、单雄群体与多雄群体组成的变化以及群体解体）的发生率上存在差异，并且与山地大猩猩相比，西部大猩猩明显表现出更高的雄性迁出率以及相应更少的多雄群体。某些现象仅被极少观察到，包括豹的捕食。初步数据显示西部大猩猩和山地大猩猩的出生率没有显著差异。大猩猩栖息地的生态变异性可能解释了大猩猩社会系统的灵活性，但我们需要更多关于西部大猩猩社会关系和生态的信息，以阐明西部和东部大猩猩在个体、社会群体和种群动态层面异同的原因。
