Biological communities may be assembled by both niche-based and dispersal-based (= historic) processes with the relative importance of these processes in community assembly being scale- and context-dependent. To infer whether (a) niche‐based or dispersal‐based processes play the main role in the assembly of flea communities parasitic on small mammals and whether (b) the main processes of flea community assembly are scale-dependent, we applied a novel permutation-based algorithm (PER-SIMPER) and the dispersal–niche continuum index (DNCI), to data on the species incidence of fleas and their hosts at two spatial scales. At the larger (continental) scale, we analysed flea communities in four biogeographic realms across adjacent continental sections. At the smaller (local) scale, we considered flea communities across two main regions (lowlands and mountains) and seven habitat types within Slovakia. Our analyses demonstrated that species composition of fleas and their small mammalian hosts depended predominantly on historical processes (dispersal) at both scale. This was true for the majority of biogeographic realms at continental scale (except the Nearctic) and both regions at local scale. Nevertheless, strong niche-based assembly mechanism was found in the Nearctic assemblages. At local scale, the intensity of dispersal processes was weaker and niche-driven processes were stronger between habitats within a region than between mountain and lowland regions. We provide historical and ecological explanations for these patterns. We conclude that the assembly of compound flea communities is governed, to a great extent, by the dispersal processes acting on their hosts and, to a lesser extent, by the niche-based processes.

生物群落可以通过基于生态位和基于扩散（=历史）的过程进行组装，这些过程在群落组装中的相对重要性取决于规模和背景。为了推断（a）基于生态位或基于扩散的过程是否在寄生在小型哺乳动物身上的跳蚤群落的组装中起主要作用，以及（b）跳蚤群落组装的主要过程是否与规模有关，我们应用了一种新的排列基于算法 (PER-SIMPER) 和分散 - 生态位连续指数 (DNCI)，以获取有关两个空间尺度上跳蚤及其寄主物种发生率的数据。在更大的（大陆）尺度上，我们分析了相邻大陆部分的四个生物地理领域的跳蚤群落。在较小的（局部）尺度上，我们考虑了斯洛伐克境内两个主要地区（低地和山区）和七种栖息地类型的跳蚤群落。我们的分析表明，跳蚤及其小型哺乳动物宿主的物种组成主要取决于两个规模的历史过程（传播）。对于大陆尺度的大多数生物地理领域（近北区除外）和局部尺度的两个区域都是如此。尽管如此，在近北区组合中发现了强大的基于生态位的组装机制。在局部尺度上，与山区和低地区域之间相比，区域内生境之间的扩散过程强度较弱，生态位驱动过程较强。我们为这些模式提供历史和生态解释。我们得出结论，复合跳蚤群落的集合在很大程度上受到控制，