Habitat Complexity and Behaviour: Personality, Habitat Selection and Territoriality

Structurally complex habitats support high species diversity and promote ecosystem health and stability, however anthropogenic activity is causing natural forms of complexity to rapidly diminish. At the population level, reductions in complexity negatively affect densities of territorial species, as...

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Bibliographic Details
Main Author: Church, Kathleen
Format: Thesis
Language:English
Published: 2018
Subjects:
Online Access:https://spectrum.library.concordia.ca/id/eprint/984494/
https://spectrum.library.concordia.ca/id/eprint/984494/1/Church_PhD_F2018.pdf
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Summary:Structurally complex habitats support high species diversity and promote ecosystem health and stability, however anthropogenic activity is causing natural forms of complexity to rapidly diminish. At the population level, reductions in complexity negatively affect densities of territorial species, as increased visual distance increases the territory size of individuals. Individual behaviour, including aggression, activity and boldness, is also altered by complexity, due to plastic behavioural responses to complexity, habitat selection by particular personality types, or both processes occurring simultaneously. This thesis explores the behavioural effects of habitat complexity in four chapters. The first chapter, a laboratory experiment based on the ideal free distribution, observes how convict cichlids (Amatitlania nigrofasciata) trade-off the higher foraging success obtainable in open habitats with the greater safety provided in complex habitats under overt predation threat. Dominants always preferred the complex habitat, forming ideal despotic distributions, while subordinates altered their habitat use in response to predation. The second chapter also employs the ideal free distribution to assess how convict cichlids within a dominance hierarchy trade-off between food monopolization and safety in the absence of a predator. Dominants again formed ideal despotic distributions in the complex habitat, while dominants with lower energetic states more strongly preferred the complex habitat. For both laboratory experiments, personality did not predict habitat preference. The third chapter, a field study with juvenile Atlantic salmon (Salmo salar), tested whether stream restorations that increase habitat complexity will also select for particular personality traits, and we again found that complexity did not favour any particular personality types. A broader range perspective regarding the effects of habitat complexity on behaviour was addressed in the fourth chapter via a meta-analysis on a wide range of territorial ...