Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, Cornwall TR10 9EZ, UK.
Biol Lett. 2011 Feb 23;7(1):54-6. doi: 10.1098/rsbl.2010.0555. Epub 2010 Aug 4.
Reproductive events in animal societies often show a high degree of temporal clustering, but the evolutionary causes of this synchronization are poorly understood. Here, we suggest that selection to avoid the negative effects of competition with other females has given rise to a remarkable degree of birth synchrony in the communal-breeding banded mongoose (Mungos mungo). Within banded mongoose groups, births are highly synchronous, with 64 per cent of females giving birth on exactly the same night. Our results indicate that this extreme synchrony arises because offspring suffer an increased risk of infanticide if their mother gives birth before other females, but suffer in competition with older littermates if their mother gives birth after them. These findings highlight the important influence that reproductive competition can have for the evolution of reproductive synchrony.
动物社会中的繁殖事件常常表现出高度的时间聚集，但这种同步的进化原因还不太清楚。在这里，我们提出，为了避免与其他雌性竞争的负面影响，选择导致了群居繁殖的斑鬣狗（Mungos mungo）中出现了显著的生育同步性。在斑鬣狗群体中，生育非常同步，64%的雌性在同一晚生育。我们的研究结果表明，这种极端的同步性是由于如果幼崽的母亲在其他雌性之前生育，它们会面临更高的杀婴风险，但如果母亲在它们之后生育，它们会在与年长的同胞竞争中受到影响。这些发现强调了繁殖竞争对生殖同步进化的重要影响。
