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Full-Text Articles in Ecology and Evolutionary Biology

Ecological Implications Of Foraging And Life-History In Three Cold-Adapted Species, Andrew Von Duyke Jan 2018

Ecological Implications Of Foraging And Life-History In Three Cold-Adapted Species, Andrew Von Duyke

Dissertations, Master's Theses and Master's Reports

This research investigates the ecology of: ringed seals (Pusa hispida), moose (Alces alces), and bowhead whales (Balaena mysticetus). Each of these species draws upon specialized strategies to meet the physical demands of life in their extreme environments. However, they are currently experiencing unprecedented changes in their habitats. This work adds to what is known about the behavior, physiology, and population dynamics of cold-adapted species—providing insights of value for an improved understanding of foraging and life-history theory, and informing conservation and ecosystem monitoring efforts. Chapter 1 provides a brief introduction to the scope of work …


The Dynamic Nature Of Forage Preference And Microhistological Atlas, John J. Henderson Jan 2018

The Dynamic Nature Of Forage Preference And Microhistological Atlas, John J. Henderson

Dissertations, Master's Theses and Master's Reports

Moose, Alces alces, are among the most iconic species in the northern circumpolar temperate forests. Multiple factors influence moose density. Winter is a time of severe dietary stress for moose because deciduous trees are leafless and available forage is limited to conifers with high plant secondary metabolites or low-energy deciduous twigs. Forage preference depends on the intrinsic forage properties, abundance of forage and environmental stressors. These stressors include predation risk and severity of climate that affect forage efficiency. We examined forage preference of moose on Isle Royale National Park during winter over a ten-year period. Diet was divided into …


The Influence Of Diet Composition, Plant Defensive Chemicals, And Winter Severity On The Nutritional Condition Of A Freeranging, Generalist Herbivore, Grace L. Parikh Jan 2015

The Influence Of Diet Composition, Plant Defensive Chemicals, And Winter Severity On The Nutritional Condition Of A Freeranging, Generalist Herbivore, Grace L. Parikh

Dissertations, Master's Theses and Master's Reports - Open

Herbivory requires animals to manage intake of toxic phytochemicals. Detoxification and excretion of these chemicals prevents toxicity, but is energetically expensive. I investigated the relationship between investment in detoxification and nutritional condition for moose on Isle Royale National Park (Alces alces) during winter, using urinary indices from urine samples collected in snow. The ratio of urinary urea nitrogen:creatinine is an indicator of nutritional condition, and the ratio of glucuronic acid:creatinine is an indicator of investment in detoxification. Nutritional condition declined with greater investment in detoxification. An alternative means of managing defensive chemical intake is to diversify the diet. Microhistological …


Spatial And Temporal Patterns In Ungulate-Ecosystem Interactions, Bryan D. Murray Jan 2013

Spatial And Temporal Patterns In Ungulate-Ecosystem Interactions, Bryan D. Murray

Dissertations, Master's Theses and Master's Reports - Open

Ungulates are important components of a variety of ecosystems worldwide. This dissertation integrates aspects of ungulate and forest ecology to increase our understanding of how they work together in ways that are of interest to natural resource managers, educators, and those who are simply curious about nature. Although animal ecology and ecosystem ecology are often studied separately, one of the general goals of this dissertation is to examine how they interact across spatial and temporal scales. Forest ecosystems are heterogeneous across a range of scales. Spatial and temporal habitat use patterns of forest ungulates tend to be congregated in patches …