Despite its potentially crucial role in improving the fit between an organism’s phenotype and the environment, relatively little is known about exactly when and how animals should use learning within their natural habitats. This thesis integrates the comparative approach with techniques traditionally developed in experimental psychology to assess how divergent habitat conditions shape learned responses in the threespine stickleback, <i>Gasterosteus aculeatus.</i> Fish collected from different habitats (ponds and rivers) were trained to learn a simple spatial task in which both landmarks and turn direction (turn left or right) reliably indicated reward location. Pond fish used both landmarks and turn direction while river fish showed a preference for using turn. In rivers, flow and turbulence may make local visual features unstable and therefore unreliable as positional cues. However, both pond and river fish fail to learn to use landmarks as goal directing cues when they are the only predictor of reward location and unstable with respect to all other sources of spatial information. A controlled rearing experiment was carried out to investigate the causal basis of cue preferences in pond and river fish. The results suggest both genetic and environmental factors may influence cue preference in the threespine stickleback. A comparison of spatial learning by sympatric species of threespine stickleback that occupy different microhabitats (pelagic and littoral zones) within the same lakes, revealed a species difference in the rate at which they learnt task. The two species may therefore be equipped with learning abilities that best suit them to either a littoral or pelagic lifestyle, even within the same macrohabitat. Together, these results suggest that learned behaviour is fine-tuned or adapted in response to local habitat conditions on a fine scale. Learning appears to operate in close conjunction with genetic and or developmental processes that enable and direct it in response to particular ecological problems.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:660162 |
| Date | January 2002 |
| Creators | Odling-Smee, Lucy C. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/15556 |
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