We study the (hydro-)dynamics of multi-species driven by alignment. What distinguishes the different species is the protocol of their interaction with the rest of the crowd: the collective motion is described by different communication kernels, ${\varphi }_{\alpha \beta }$, between the crowds in species α and β. We show that flocking of the overall crowd emerges provided the communication array between species forms a connected graph. In particular, the crowd within each species need not interact with its own kind, i.e., ${\varphi }_{\alpha \alpha }=0$; different species which are engaged in such ‘game’ of alignment require a connecting path for propagation of information which will lead to the flocking of overall crowd. The same methodology applies to multi-species aggregation dynamics governed by first-order alignment: connectivity implies concentration around an emerging consensus.

我们研究由对齐驱动的多物种的（流体）动力学。不同物种的区别在于它们与其他人群互动的协议：集体运动由不同的通信内核描述，${\phi }_{\alpha \beta }$，在物种α和β的人群之间。我们表明，如果物种之间的通信阵列形成一个连通图，就会出现整体人群的聚集。特别是，每个物种内的人群需要不与它自己的一种互动，即${\phi }_{\alpha \alpha }=0$; 参与这种对齐“游戏”的不同物种需要一条连接路径来传播信息，这将导致整个人群蜂拥而至。相同的方法适用于由一阶对齐控制的多物种聚集动态：连通性意味着围绕新兴共识的集中。