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The behaviour of wood ant foragers at the individual cohort and colony levels in the exploitation of carbohydrate food provided in nature by aphid aggregations

Aspects of the behaviour of the wood ant <I>Formica aquilonia</I> were studied using semi-natural conditions in the laboratory and under natural conditions in Loch Ard Forest, Aberfoyle, Scotland. In this study the main effort was towards an understanding how the foraging population is structured and controlled. As the preferred food site of the foragers is often the first located site: maximisation of the net energetic yield of the colony as a whole may conflict with the optimal foraging as measured at the individual level. Site allegiance is a constant property of certain individuals within the colony's foraging population. A key component of the foraging system is a mechanism whereby a colony keeps a large proportion of its forager force distributed on the most profitable food sites whilst it members show strong site allegiance. Wood ants discriminate food sources without making comparisons among honeydew sources. Naive foragers show transient behaviours in their foraging repertory more often that veteran, allegiant foragers. This behaviourally flexibility of naive foragers is used to trace novel food sties likely to occur in the habitat. It is represented in this study by the small number of foragers recruited daily. By this recruiting of uncommitted foragers to the foraging population <I>F. aquilonia</I> colonies are able to overcome inherent inertia associated with site allegiance. Although significant differences may be observed at the foragers' level of activity, there are no sub populations operating at day and night time. The gradual declining activity observed when the colony was subjected to a 17.5:6.5 light:dark cycle does not begin immediately after the light out. The rhythmicity was poor in constant dark and complete arhythmicity in constant light suggesting that these rhythms are entrained by light:dark cycles. There was no evidence found to support that <I>F. aquilonia</I> foragers depend on chemical cues to orient to carbohydrate food sources: mainly honeydew provided by aphids.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:652399
Date January 1998
CreatorsHewage, Sagarika Chandanie Pathirana
PublisherUniversity of Edinburgh
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://hdl.handle.net/1842/15020

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