Data from: Social structure of the harem-forming promiscuous fruit bat, Cynopterus sphinx, is the harem truly important?

Bats are social animals and display a diverse variety of mating and social systems, with most species exhibiting some form of polygyny. Their social organisation is fluid and individuals frequently switch partners and roosting sites. While harem-like social organisation is observed in multiple tropical species, its importance is contested in many of them. In this study we investigated the role of harems in the social organisation of the old world fruit bat Cynopterus sphinx. Based on regular behavioural observations over a period of 20 months and genetic data from microsatellite markers, we observed that the social organisation is flexible, individuals regularly shift between roosts and the social organisation resembles a fission-fusion society. Behavioural and genetic analyses suggest that the harems are not strict units of social structure, and the colony does not show signatures of subdivision with harems as behavioural units. We also observed that there was no correlation between individuals with high association index and pairwise relatedness. Our findings indicate that similar to the mating system, the social organization of C. sphinx can also be categorized as a fission-fusion society, and hence the term ‘harem’ is a misnomer. We conclude that the social system of C. sphinx is flexible, with multi-male multi-female organisation and individuals tend to be loyal to a given area rather than a roost.

蝙蝠是群居动物，展现出多样的交配与社会体系，多数物种呈现某种形式的一雄多雌制（polygyny）。它们的社会结构具有流动性，个体常会更换交配伴侣与栖息位点。尽管多种热带蝙蝠物种中观察到类似妻妾群（harem）的社会结构，但该结构在多数此类物种中的重要性仍存在争议。本研究针对旧大陆果蝠犬蝠（Cynopterus sphinx）的社会结构中妻妾群的作用展开了探究。基于为期20个月的常规行为观测与微卫星标记（microsatellite markers）遗传数据，本研究发现该物种的社会结构具有灵活性：个体频繁在栖息位点间移动，其社会体系类似裂合-融合社会（fission-fusion society）。行为与遗传分析结果表明，妻妾群并非严格的社会结构单元，该种群并未呈现以妻妾群为行为单元的分化特征。此外，本研究发现关联指数较高的个体间，并无显著的两两亲缘相关性。本研究结果显示，与交配体系一致，犬蝠的社会结构同样可归类为裂合-融合社会，因此“妻妾群”这一术语实为误称。综上，本研究认为犬蝠的社会体系具有灵活性，其为多雄多雌结构，且个体更倾向于忠于特定区域而非某一栖息位点。