Date of Award
Summer 8-22-2025
Level of Access Assigned by Author
Open-Access Thesis
Degree Name
Doctor of Philosophy (PhD)
Department
Ecology and Environmental Sciences
First Committee Advisor
Alessio Mortelliti
Second Committee Member
Sydne Record
Third Committee Member
Sabrina Morano
Additional Committee Members
Brian McGill
Aaron Weiskittel
Abstract
Forests are a critical global resource, providing habitat for wildlife, storing carbon, and contributing to the global economy. Forests are facing pressure, however, from forest management and climate change, which is causing poleward range shifts for many tree species. It is critical to understand the response of forests to these pressures, predicting future regeneration, composition, and range limits, to sustainably manage and preserve our forests. Small mammals, including mice, voles, and squirrels, are the main seed predators and dispersers of many of Maine’s woody tree species, eating many seeds and beneficially dispersing and caching some, enhancing their germination potential. Thus, small mammals’ seed dispersing behavior, spatial distribution, and reaction to novel seeds is a critical component of understanding and predicting forests’ responses to climate change and management. Additionally, personality, or consistent intraspecific behavioral variation, mediates small mammal behaviors. Thus, this dissertation evaluates the consequences of small mammal personality on their foraging and seed dispersal decisions and habitat selection to enhance our understanding of forest regeneration.
Chapter 1 investigates the foraging behavior of southern red-backed voles at covered (i.e., safe) versus uncovered (i.e., risky) foraging sites to evaluate the role of personality and perceived predation risk on vole seed selection and consumption. Chapter 2 assesses how mice and voles with different personalities prioritize perceived predation risk (i.e., microhabitat cover), real predation risk (i.e., predator presence), and competition differently when selecting habitat in a landscape of fear. Chapter 3 uses a large-scale study, spanning the northern range limits of multiple oak and hickory species, to evaluate gray squirrels’ willingness to select and disperse novel seeds and the role of intraspecific variation in these decisions. Chapter 4 focuses on the foraging effectiveness of small mammals, quantifying the effects of personality on the number of seeds mice and voles find at a foraging site and their seed finding rate. Lastly, Chapter 5 ties together each step of the seed dispersal process to evaluate how the population abundance, spatial arrangement, and personality distribution of a small mammal population affects the number of cached seeds and thus the regeneration of a forest stand.
Recommended Citation
Merz, Margaret, "Ecological Consequences of Small Mammal Personalities in Forest Ecosystems" (2025). Electronic Theses and Dissertations. 4217.
https://digitalcommons.library.umaine.edu/etd/4217
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