Many recent studies show that synchronisation of various behaviours are advantageous for group-living mammals. However, studies on synchronisation of suckling behaviour inmonotocous species are nearly absent. We observed 49 individual foals of three zebra species in Dvůr Králové Zoo, and recorded a total of 5 890 suckling bouts, almost one fifth (1 036) of which were synchronised (defined as at least two bouts overlapping at the same time). We found that synchronised suckling bouts lasted longer and were less likely to be terminated by the mother than non-synchronised ones. This is in line with social facilitation theory. In addition the occurrence of synchronised suckling bout differed interspecifically. In plains (Equus quagga) and mountain zebra (E. zebra) the probability of synchronised bouts increased with increasing numbers of foals, whereas the opposite result was found in Grevy’s zebra (E. grevyi). We suggest that the interspecific differences may reflect differences in social organisation of respective species as suckling synchronisation rate was higher in species that form nurseries in the wild.

最近的许多研究表明，各种行为的同步对群居哺乳动物是有利的。然而，几乎没有关于单头物种哺乳行为同步的研究。我们在 Dvůr Králové 动物园观察了 3 种斑马的 49 只个体小马驹，共记录了 5 890 次哺乳期，其中几乎五分之一（1 036 次）是同步的（定义为至少两次同时重叠）。我们发现，与非同步哺乳相比，同步哺乳的持续时间更长，被母亲终止的可能性更小。这符合社会促进理论。此外，同步哺乳回合的发生因种而异。在平原（Equus quagga）和山地斑马（E. zebra) 同步比赛的概率随着马驹数量的增加而增加，而在 Grevy 的斑马 ( E. grevyi ) 中发现了相反的结果。我们认为种间差异可能反映了各个物种社会组织的差异，因为在野外形成苗圃的物种的哺乳同步率较高。