A 15-Year Perspective on the Social Organization and Life History of Sifaka in Kirindy Forest
A 15-Year Perspective on the Social Organization and Life History of Sifaka in Kirindy Forest
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基林迪森林西法卡社会组织和生活史15年透视
DOI：
10.1007/978-3-642-22514-7_5
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发表时间：
2012
影响因子：
1.4
通讯作者：
C. Fichtel
中科院分区：
文献类型：
--
作者：
P. Kappeler;C. Fichtel
在本章中，我们总结了对马达加斯加西部 Kirindy 森林的 Verreaux sifaka (Propithecus verreauxi) 进行长期研究的头 15 年的一些基本人口统计和形态测量数据。我们首先描述这个研究地点、它的历史和基础设施，以及用于研究当地西法卡种群的方法。从 1995 年开始，对多达 11 个群体的成员进行定期人口普查、行为观察和系统捕获，并产生了人口统计和生活史数据集，可以提供有关西法卡生活史的比较见解。我们的分析显示，多年来平均群体规模波动很小，平均为 6 个人。群体组成因分散（主要是男性转移）或失踪、出生和死亡而改变。捕食和雌性转移是引发群体灭绝和新群体形成的主要机制（149个群体年中N=5例）。这些特殊的雌性转移案例很可能是由雌性竞争或避免近亲繁殖引起的。一名女性至少属于四个不同群体的成员。第一次生育的中位年龄为 5 岁。所有雌性都产下单婴，但成年雌性的繁殖比例多年来变化在 25% 至 85% 之间。 112 次生育之间的平均间隔为 15.1 个月。断奶前失去婴儿仅使随后的生育间隔缩短约 1 个月。随着每组成年雌性数量的增加，个体雌性成功繁殖的概率下降，这意味着雌性竞争的微妙形式限制了群体规模。生命最初两年的死亡率特别高（62%）。窝（Cryptoprocta ferox）的捕食是导致死亡的主要原因。女性的最长生殖寿命至少为15年，但寿命仍无法估计。这些分析揭示了对女性生殖策略及其与社会组织相互作用的新见解，这只有由于研究的长期性质才可能实现，但样本量较小的问题仍然限制了许多生命统计数据的分析。
In this chapter, we summarize some fundamental demographic and morphometric data from the first 15 years of a long-term study of Verreaux’s sifaka (Propithecus verreauxi) at Kirindy Forest in Western Madagascar. We first describe this research site, its history, and infrastructure, as well as the methods employed to study a local sifaka population. Regular censuses, behavioral observations, and systematic captures of members of up to 11 groups began in 1995 and yielded a data set on demography and life history that can contribute comparative insights about sifaka life history. Our analyses revealed that average group size fluctuated very little around a mean of six individuals across years. Group composition was modified by dispersal (mostly male transfers) or disappearances, births, and deaths. Predation and female transfer were the main mechanisms triggering group extinctions and foundation of new groups (N=5 cases in 149 group years). These exceptional cases of female transfer were most likely motivated by female competition or inbreeding avoidance. One female was a member of at least four different groups. Median age at first birth was 5 years. All females gave birth to single infants, but the proportion of adult females reproducing varied between 25 and 85% across years. The mean interval between 112 births was 15.1 months. Loss of an infant before weaning reduced the subsequent inter-birth interval only by about 1 month. The probability that individual females reproduced successfully decreased as the number of adult females per group increased, implying that subtle forms of female competition limit group size. Mortality is especially high (62%) in the first 2 years of life. Predation by the fossa (Cryptoprocta ferox) is the main cause of death. Maximum female reproductive lifespan is at least 15 years, but longevity is still impossible to estimate. These analyses revealed new insights into female reproductive strategies and their interaction with social organization that were only possible because of the long-term nature of the study, but problems of small sample size still limit the analysis of many vital statistics.