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2018

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Articles 1021 - 1031 of 1031

Full-Text Articles in Ecology and Evolutionary Biology

The Value Of Animal Behaviour As A Bio-Indicator Of Restoration Quality, Floyd Holmes Jan 2018

The Value Of Animal Behaviour As A Bio-Indicator Of Restoration Quality, Floyd Holmes

Theses: Doctorates and Masters

Woodland restoration is a complex endeavour, and restoration ecology as a scientific discipline requires constant re-assessments and adjustments if it is to improve outcomes and better provide for biodiversity. The promise of effective restoration is often used to justify destructive processes that affect many of the world’s ecosystems. It is therefore imperative that those promises can be met, which comes down to restoration ecologists’ and land managers’ capacity to predict and facilitate desirable ecological changes in a timely and socio-economically responsible manner. As perspectives have changed, and knowledge has been gained over the past few decades there have been several …

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Survival, Movements, And Resource Selection Of Female White-Tailed Deer In Missouri, Chloe A. Wright Jan 2018

Survival, Movements, And Resource Selection Of Female White-Tailed Deer In Missouri, Chloe A. Wright

Graduate Student Theses, Dissertations, & Professional Papers

White-tailed deer (Odocoileus virginianus) in Missouri are a socially and economically important game species generating annual revenue in excess of $1 billion. The last comprehensive deer study in Missouri was conducted in the 1980s – 1990s when deer populations were rapidly expanding. Since this time there has been a reduction in deer population size, declining growth rates, changes in harvest strategies, and the emergence and spread of chronic wasting disease (CWD). These changes have rendered prior survival estimates outdated, and the presence of CWD requires a deeper understanding of movement patterns and space use. We were interested in …

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Avian Community Responses To Bison Grazing In North American Intermountain Grasslands, Danielle A. Fagre Jan 2018

Avian Community Responses To Bison Grazing In North American Intermountain Grasslands, Danielle A. Fagre

Graduate Student Theses, Dissertations, & Professional Papers

Grassland and shrubland songbird species are a guild of conservation concern in North America. Many of these species have experienced severe population declines, due to habitat loss and land use change. This makes the conservation and management of remaining habitat of crucial importance for this guild. Grazing by large herbivores is an ecosystem process in grassland systems, and in North America, one of the major historic grazers was the Plains bison (Bison bison). Bison are considered ecosystem engineers, because they modify habitat to be more or less suitable for other species, such as grassland and shrubland songbirds. Bison …

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The Ethosophy Of The Grizzly Man: Timothy Treadwell's Three Ethologies, Blake L. Ginsburg Jan 2018

The Ethosophy Of The Grizzly Man: Timothy Treadwell's Three Ethologies, Blake L. Ginsburg

Graduate Student Theses, Dissertations, & Professional Papers

This paper explores the ethical appropriateness and significance of Timothy Treadwell’s life among the bears and foxes of Alaska’s Katmai National Park and Preserve. In an attempt to reveal the formative and transformative aspects of Treadwell’s project, I rely upon an ethological framework developed by Matthew Calarco that moves beyond the narrow conception of ethology as a scientific practice aimed at systematic and rigorous documentation of the quantifiable aspects of animal behavior. While many people might be hesitant to conceive of Treadwell’s project as an ethological one, I hope to illuminate the ways in which his life among bears and …

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Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee Jan 2018

Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee

Graduate Student Theses, Dissertations, & Professional Papers

Long-term viability of endangered populations requires development of effective management strategies that target the population vital rate with the highest potential to influence population trajectories. When adult survival is high and stable, juvenile recruitment is the vital rate with the greatest potential to improve population trajectories. For my thesis I examined how lactating Sierra Nevada Bighorn sheep (Ovis Canadensis sierra) balance forage and predation risk during the neonatal period. I first identified resource selection strategies employed by lactating females to promote survival of neonates and then determined the primary factors affecting survival of neonates. I found lactating females selected for …

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Bottom-Up And Top-Down Controls On Food Webs In Headwater Streams, Miriam O. Bayer Jan 2018

Bottom-Up And Top-Down Controls On Food Webs In Headwater Streams, Miriam O. Bayer

Graduate Student Theses, Dissertations, & Professional Papers

Headwater streams account for 70% of stream channel length in the USA and are important as hotspots of nutrient uptake and native biodiversity. Biofilm, the mixed auto- and heterotrophic microbial community covering stream substrates, is where the majority of nutrient processing occurs, and forms the base of stream food webs, particularly in heavily shaded, oligotrophic streams. Both bottom-up (e.g., nutrients, light) and top-down (i.e., consumption) processes are known to affect periphyton, the autotrophic component of biofilm, but little is known about what controls the biofilm community as a whole. Top-down effects are common in streams, where fish are often the …

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Persistence Of Stream Restoration With Large Wood, Redwood National And State Parks, California, Diedra L. Rodriguez Jan 2018

Persistence Of Stream Restoration With Large Wood, Redwood National And State Parks, California, Diedra L. Rodriguez

Cal Poly Humboldt theses and projects

The conservation and recovery of anadromous salmonids (Oncorhynchus sp.) depend on stream restoration and protection of freshwater habitats. In-stream large wood dictates channel morphology, increases retention of terrestrial inputs such as organic matter, nutrients and sediment, and enhances the quality of fish habitat. Historic land use/land cover changes have resulted in aquatic systems devoid of large wood. Restoration by placement of large wood jams is intended to restore physical and biological processes. An important question for scientists and restoration managers, in addition to the initial effectiveness of restoration, is the persistence and fate of large wood installations. In this …

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Apparent Survival Of Snowy Plovers Varies Seasonally, Nora C. Papian Jan 2018

Apparent Survival Of Snowy Plovers Varies Seasonally, Nora C. Papian

Cal Poly Humboldt theses and projects

Survival is an important vital rate that contributes to population viability, but is infrequently monitored and studied, especially compared to productivity. Furthermore, factors that limit survival and the relative effect on survival are often unknown. I used mark-resight observations of a small (~350) population of threatened Snowy Plovers (Charadrius nivosus nivosus) to quantify seasonal and annual variation in survival and movement between three coastal locations across ~70 km in Humboldt County, California. The return of individuals to non-breeding flocks at three locations was high between years (75-81%). Movement between three locations varied greatly, although most (n = 137) …

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Seasonal Home Range Variation And Spatial Ecology Of Peregrine Falcons (Falco Peregrinus) In Coastal Humboldt County, Ca, Elizabeth-Noelle F. Morata Jan 2018

Seasonal Home Range Variation And Spatial Ecology Of Peregrine Falcons (Falco Peregrinus) In Coastal Humboldt County, Ca, Elizabeth-Noelle F. Morata

Cal Poly Humboldt theses and projects

Peregrine falcons (Falco peregrinus) are renowned for their migratory habits, with ‘peregrinus’ often translated as ‘wanderer’ or ‘pilgrim’. However, their migratory habits may differ by population and some peregrine may falcons forgo migration when climate and resources remain stable. To examine peregrine falcon home range and space use, I fitted GPS-satellite transmitters to nine breeding adults in coastal northern California, an area with a mild climate and abundant waterbird populations. I used kernel density estimates and time-local convex hulls to examine seasonal home ranges and within-home range habitat use. All nine peregrine falcons remained resident in …

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A Comparison Of Community Structure In Regulated And Unregulated Reaches In The Upper Eel River, California, Lara Stephanie Jansen Jan 2018

A Comparison Of Community Structure In Regulated And Unregulated Reaches In The Upper Eel River, California, Lara Stephanie Jansen

Cal Poly Humboldt theses and projects

Flow regulation of rivers by impoundments and diversions can reduce hydrological variability. As a result, densities of algae and benthic macroinvertebrates often increase, but many sensitive taxa are lost, causing shifts across the food web. In Northern California, dams that reduce winter peak floods can result in the primary consumer community becoming dominated by grazers that are relatively invulnerable to predation, which can reduce the amount of energy transferred up the trophic levels. The steeper slope of the spring hydrograph recession limb downstream of a dam can also greatly impact instream diversity of periphyton, invertebrates and fish. The dam and …

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Evaluating Habitat Selection Models To Improve Site Selection In A Population Monitoring Program For Townsend's Big-Eared Bats (Corynorhinus Townsendii), Katrina J. Smith Jan 2018

Evaluating Habitat Selection Models To Improve Site Selection In A Population Monitoring Program For Townsend's Big-Eared Bats (Corynorhinus Townsendii), Katrina J. Smith

Cal Poly Humboldt theses and projects

Winter roost (hibernacula) surveys offer a unique opportunity to monitor Townsend’s big-eared bats (Corynorhinus townsendii) while the population is generally closed, using a simple count method to census the population. Existing knowledge of C. townsendii hibernacula facilitates long-term population trend analysis but improving the accuracy of trend estimates requires identification of additional hibernacula to increase the proportion of the population monitored. Over 800 caves are known within Lava Beds National Monument; 322 of these have never been surveyed in the winter and could potentially hold a substantial portion of the C. townsendii population currently missing from the annual …

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