The role of seed attributes in eastern gray squirrel foraging

<p>Seed attributes are important predictors of rodent foraging behaviors. I examined the role of seed attributes in eastern gray squirrel (Sciurus carolinensis) foraging behavior from an evolutionary, economic, ecological and biochemical perspective. From an evolutionary perspective (chapter 2), I found that squirrel foraging behaviors are influenced by a combination of phylogenetically conserved and evolutionarily labile seed traits, which supports a diffuse coevolutionary relationship between hardwood trees and squirrels and provides indirect evidence supporting the Janzen-Connell and handling time hypotheses. From an economic perspective (chapter 3), I found that eastern gray squirrels are homogenous with respect to their preferences for seed attributes, which is likely due to natural selection favoring caching of specific seeds in the fall. I also provide evidence that squirrels trade between 3 attributes when selecting seeds for caching, which results in a variety of seed types being cached. In contrast, squirrels trade between 2 attributes when selecting seeds for consumption, which leads to fewer seed types being consumed in the fall. From an ecological context perspective (chapter 4), I provide evidence of seed traits interacting with relative seed availability to predict caching. Specifically, when seeds of different caching value (i.e., utility) were paired, relative frequency of availability played a minimal role in predicting seed caching. In contrast when seeds of similar caching utility were paired, relative frequency of availability significantly influenced probability of seed selection for caching. From a biochemical perspective (chapter 5), I identified biochemical and anatomical changes at the cellular level associated with radicle dormancy that serve as a signal of lack of dormancy to eastern gray squirrels. In combination, my dissertation chapters support the existence of complex reciprocal evolutionary effects between hardwood trees and eastern gray squirrels.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Forestry and Natural Resources

Year

2016

Author dc:creator

• Sundaram, Mekala

Contributors dc:contributor

• Robert K. Swihart
• Nicole J. Olynk Widmar
• Michael A. Steele
• Patrick A. Zollner

• Biological sciences
• Wildlife Management
• Caching
• Consumption
• Hardwood trees
• Sciurus carolinensis
• Selection
• Biology
• Ecology and Evolutionary Biology

Repository record dc:identifier

https://docs.lib.purdue.edu/open_access_dissertations/1009

OAI identifier oai:identifier

oai:docs.lib.purdue.edu:open_access_dissertations-2224