Heterogeneous environments play an important role in the evolution of traits when selection is diversifying between different conditions. One response is the capacity of individuals to beneficially adjust their phenotype to local conditions, such as different predators. In larval Enallagma damselflies, diversifying selection from predatory dragonfly larvae or predatory fish favours opposing traits, respectively high or low levels of activity, and so appears to drive the adaptive divergence of anti-predator specialists. However, little work has addressed: i) if anti-predator generalist species exist; ii) if anti-predator generalist species express adaptive flexible behaviour; iii) if adaptive flexible behaviour is influenced by prior experience with predators. I compared individual larval behaviour in the presence of fish, dragonfly larvae, or no predators, in four Enallagma species groups from ponds with and without fish predators. Ecological distributions suggest variation in degree of anti-predator generalization, and this was associated with increased responsiveness to predator treatment in the most likely ecological generalist. Responses to predators varied across different behaviours and sometimes were shaped by prior predation experience. Thus, a variety of adaptive strategies may have evolved to cope with heterogeneity in predation risk in larval damselflies. / NSERC, OGS
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OGU.10214/5426 |
| Date | 31 January 2013 |
| Creators | Brown, Allison |
| Contributors | Robinson, Beren |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by/2.5/ca/ |
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