Fission-fusion social systems involve the splitting and merging of subgroups with frequent changes in membership occurring as a result of a number of ecological and social factors, such as demographic processes including birth, movement, or death. Giraffe reside in fission-fusion social systems, and we studied how reproductive status influence associations among females, as well as how associations differ between calves and juveniles. Data were collected in Katavi National Park, Tanzania, during five study periods. We used social network analysis to identify whether reproductive status and developmental stages predict differences in giraffe social association. We found that females with offspring maintain stronger associations than females without offspring. We also revealed that calves and juveniles had similar network association patterns. Our results suggest that the presence of dependent offspring influences the social associations of females and individuals less than 1.5 years of age are still maintaining strong social associations with nursery group members. We conclude that nursery groups among giraffe are co-operative rearing units that probably reduce the costs of rearing to mothers, and may provide a group structure for animals to begin to develop skills useful for their future life in a fission-fusion social system.

中文翻译：

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马赛长颈鹿保育团体对女性和年轻人社会交往发展的影响

裂变融合社会系统涉及子群体的分裂和合并，成员身份经常发生变化，这是由于许多生态和社会因素（例如出生、移动或死亡等人口过程）造成的。长颈鹿居住在裂变融合社会系统中，我们研究了生殖状态如何影响雌性之间的关联，以及小牛和幼年之间的关联有何不同。数据是在五个研究期间在坦桑尼亚卡塔维国家公园收集的。我们使用社交网络分析来确定生殖状态和发育阶段是否可以预测长颈鹿社会关联的差异。我们发现有后代的雌性比没有后代的雌性保持更强的关联。我们还揭示了小牛和幼鱼具有相似的网络关联模式。我们的研究结果表明，依赖后代的存在影响了女性的社会交往，而 1.5 岁以下的个体仍然与托儿所成员保持着强烈的社会交往。我们得出的结论是，长颈鹿的保育小组是合作饲养单位，可能会降低母亲的饲养成本，并可能为动物提供一个群体结构，以开始发展对它们在裂变融合社会系统中的未来生活有用的技能。