In this thesis, I use a large scale study on the dwarf angelfish <i>Centropyge bicolor </i>to investigate social conflict resolution in a linear hierarchy. Body-size based linear dominance hierarchies in social fishes have great potential to provide insight into within-group conflict resolution, with recent work demonstrating that group stability may be achieved by subordinate regulating their growth rates to avoid punishment by eviction. How subordinates can assess the imminence of punishment remains a crucial outstanding question: despite suggestions that dominant aggression rates might provide the crucial mechanism, the expected aggressive patterns have yet to be empirically demonstrated. I begin by laying the groundwork for social conflict studies in <i>Centropyge bicolor </i>by quantifying multiple behavioural correlates of social rank. I first show that spatial segregation has confounding effects on the behavioural patterns between dominants and subordinates, with important consequences for dyadic relationships and overall group stability. By focusing on spatially overlapping groups, I then show that dominant aggression rates increase gradually as subordinates get relatively larger; subordinates that are too close in size to dominants are evicted from the group. Subordinates respond to the aggressive signal of imminent eviction by reducing their foraging and growth rates, resulting in a clearly-defined size hierarchy and continued group stability. The necessary maintenance of a well-separated size hierarchy places limits on maximum group size. Well-regulated subordinate size results in a neutral effect of subordinates on dominant fitness. My results present a uniquely complete view of the causes and consequences of conflict resolution in linear dominance.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:596123 |
| Date | January 2010 |
| Creators | Ang, T. Z. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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