Date of Award

Spring 1-1-2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Ecology & Evolutionary Biology

First Advisor

Brett A. Melbourne

Second Advisor

Alexander Cruz

Third Advisor

Rebecca Safran

Fourth Advisor

Robert Guralnick

Fifth Advisor

Barbara P. Buttenfield

Abstract

Relative motion is an ecological mechanism with the power to change the stability and longevity of populations and predict large scale movement patterns in highly mobile species. This dissertation introduces relative motion as an ecological mechanism using simulations and experiments at varying levels of spatial complexity. Chapters 2 and 3 describe the interactions between population movement and one-dimensional habitat movement, while Chapters 4 and 5 focus on the interactions between individual movement and three-dimensional habitat movement. Chapters 2 and 4 lay out my model justification, model development, and simulation results, while the remaining two chapters describe case studies competing those models with data. In Chapter 2, I simulate populations chasing moving habitat using stochastic spatial spread models. Results from these simulations show that populations lose symmetry when the habitat begins to move and suggest that loss of symmetry increases extinction risk. Results also show that assisted migration can restore some of that lost symmetry, but the success of assisted migration is sensitive to the transplant location and habitat speed. In Chapter 3, I build on the simulations presented in Chapter 2 by investigating assisted migration as a method of restoring symmetry using Tribolium microcosm experiments. Experimental results show that assisted migration both restored symmetry to the moving populations under fast-moving habitat conditions and significantly reduced extinction risk compared to the controls. Chapter 4 describes a 3-dimensional Geographic Information System (GIS) to track multiple sources of relative motion in the environment at once, using rigid body mathematics to move individual components in their own direction. In Chapter 5, I apply this GIS to deconstruct the migratory paths of 22 Greater shearwater (Puffinus gravis) migrants and rank the relative contributions of solar, wind, temperature, humidity, and surface cues to the figure-8 shaped migratory paths observed in this species.

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