Date of Award

Summer 9-20-2022

Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Ecology and Environmental Sciences

Advisor

Alessio Mortelliti

Second Committee Member

Erik J. Blomberg

Third Committee Member

Shawn Fraver

Additional Committee Members

Malcolm Hunter Jr.

Brian McGill

Abstract

Variation among individuals is at the root of all evolution by means of natural selection. However, only in recent years has intraspecific behavioral variation been embraced as a potential driver of community and ecosystem processes, rather than considered statistical noise. Animal personalities, or behavioral differences between conspecifics that are consistent across time and contexts, are one such form of variation that has received considerable attention in the last two decades. Investigations of the ecological and ecosystem consequences of personality variation is at the current forefront of the field, but much work on this topic remains conceptual. Here, I apply large-scale field experiments and provide empirical evidence for three mechanisms by which personality variation can scale up to influence processes at the population and ecosystem level. Using the small mammal community in Maine's temperate mixed forests as a model system (specifically, deer mice, Peromyscus maniculatus, southern red-backed voles, Myodes gapperi, northern short-tailed shrews, Blarina brevicauda, and North American red squirrels (Tamiasciurus hudsonicus), in Chapter 1 I use a field experiment to confirm that methods of live-trapping do not confound behavioral measurements obtained from standardized assays. Chapter 2 examines four years of detailed trapping data and fine-scale habitat measures to identify population-level correlations between personality traits and habitat selection. Chapter 3 investigates the understudied role of intraspecific behavioral variation in mutualisms by examining the propensity for personality traits of scatter-hoarders to generate context-dependence in the seed dispersal mutualism. Finally, Chapter 4 examines the effects of personality differences on detection, movement, and survival of small mammals. Using an empirical approach, this dissertation highlights three mechanisms through which animal personalities can influence animal populations and ecosystem function. Ultimately, this dissertation provides important empirical evidence of the ecological consequences of animal personalities and should be a catalyst for prospective work on this topic.

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