Ellis Samuel, Robinson Elva J H
Department of Biology, University of York, York, YO10 5DD, United Kingdom; York Centre for Complex Systems Analysis, University of York, York, YO10 5DD, United Kingdom.
PLoS One. 2015 Oct 14;10(10):e0138321. doi: 10.1371/journal.pone.0138321. eCollection 2015.
A colony of red wood ants can inhabit more than one spatially separated nest, in a strategy called polydomy. Some nests within these polydomous colonies have no foraging trails to aphid colonies in the canopy. In this study we identify and investigate the possible roles of non-foraging nests in polydomous colonies of the wood ant Formica lugubris. To investigate the role of non-foraging nests we: (i) monitored colonies for three years; (ii) observed the resources being transported between non-foraging nests and the rest of the colony; (iii) measured the amount of extra-nest activity around non-foraging and foraging nests. We used these datasets to investigate the extent to which non-foraging nests within polydomous colonies are acting as: part of the colony expansion process; hunting and scavenging specialists; brood-development specialists; seasonal foragers; or a selfish strategy exploiting the foraging effort of the rest of the colony. We found that, rather than having a specialised role, non-foraging nests are part of the process of colony expansion. Polydomous colonies expand by founding new nests in the area surrounding the existing nests. Nests founded near food begin foraging and become part of the colony; other nests are not founded near food sources and do not initially forage. Some of these non-foraging nests eventually begin foraging; others do not and are abandoned. This is a method of colony growth not available to colonies inhabiting a single nest, and may be an important advantage of the polydomous nesting strategy, allowing the colony to expand into profitable areas.
红木蚁群体可以栖息在多个空间上相互分离的巢穴中，这种策略被称为多蚁巢型。在这些多蚁巢型群体中，有些巢穴没有通往树冠层蚜虫群落的觅食路径。在本研究中，我们识别并调查了在黑褐蚁多蚁巢型群体中不觅食巢穴可能发挥的作用。为了研究不觅食巢穴的作用，我们：（i）对蚁群进行了三年的监测；（ii）观察了不觅食巢穴与蚁群其他部分之间运输的资源；（iii）测量了不觅食巢穴和觅食巢穴周围的巢外活动量。我们利用这些数据集来研究多蚁巢型群体中的不觅食巢穴在多大程度上充当以下角色：蚁群扩张过程的一部分；狩猎和 scavenging specialists（此处英文有误，可能是scavenging specialists，意为食腐专家）；育雏发育专家；季节性觅食者；或者是一种利用蚁群其他部分觅食努力的自私策略。我们发现，不觅食巢穴并非具有专门的作用，而是蚁群扩张过程的一部分。多蚁巢型蚁群通过在现有巢穴周围区域建立新巢穴来扩张。在食物附近建立的巢穴开始觅食并成为蚁群的一部分；其他巢穴不是在食物源附近建立的，最初并不觅食。其中一些不觅食巢穴最终开始觅食；其他的则不觅食并被废弃。这是一种单巢栖息蚁群所没有的蚁群增长方式，可能是多蚁巢型筑巢策略的一个重要优势，使蚁群能够扩展到有利可图的区域。
