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Ant defence system: A mechanism organizing individual responses into efficient collective behavior
Author(s) -
Sakata Hiroshi,
Katayama Noboru
Publication year - 2001
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1046/j.1440-1703.2001.00404.x
Subject(s) - lasius , foraging , ecology , eusociality , nest (protein structural motif) , ant , biology , context (archaeology) , ant colony , honeydew , mechanism (biology) , aggression , social psychology , psychology , hymenoptera , computer science , biochemistry , paleontology , algorithm , ant colony optimization algorithms , philosophy , epistemology
A colony of social insects is an excellent model for investigating the organization of responses of subunits (i.e. colony members) with limited skills into sophisticated collective behavior. The defence system of Lasius niger ant colonies is well organized in a context‐dependent way. The proportion of fighting ants to fleeing ants changes gradually according to the importance of the area being defended, and was higher where ants tended honeydew‐rich aphids and on trails for foraging with heavy traffic, than where ants were walking alone or on trails with light traffic. Although there were intrinsic differences in aggressiveness between individual ants, the differences in aggressive responses between defended areas was not due to the presence of highly aggressive or timid individuals in each area. Instead, it was due to a change in aggressiveness of individuals in response to external conditions. The cue that altered individual aggressiveness was the presence of surrounding nest‐mates, rather than the presence of aphids. We concluded that the defence system of this ant species consists of three processes: (i) a recruiting system that allocates more workers to more valuable resources; (ii) individual ants following a simple decision rule to become more aggressive in response to increased numbers of nest‐mates nearby (hence aggressive behavior reflecting the importance of each area to the colony); and (iii) variability in individual responses causing a gradual change in the proportion of fighting ants responding to a threat.