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Ornithology

Theses/Dissertations

2021

Articles 1 - 13 of 13

Full-Text Articles in Ecology and Evolutionary Biology

Brood Abundance And Invertebrate Availability In Crop-Dominated Landscapes In The Prairie Pothole Region, Catrina V. Terry Nov 2021

Brood Abundance And Invertebrate Availability In Crop-Dominated Landscapes In The Prairie Pothole Region, Catrina V. Terry

LSU Master's Theses

The Prairie Pothole Region (PPR) is the most important region for ducks in North America, producing over half the ducks on the continent, and it is a priority landscape for wetland and grassland conservation. Agricultural expansion has changed the PPR, and the majority of grasslands and potholes have been converted into row-crops. The loss of nesting habitat has directly caused nest success to decline. Most of the remaining wetlands are surrounded by row-crops, and are considered lower quality because they receive runoff of sediment and chemicals, which may decrease primary forage for young ducklings as well as inhibit wetland vegetation. …


Vertebrate Scavenger Diversity And Ecosystem Services Along An Elevational Gradient In Central Nepal, Aishwarya Bhattacharjee Sep 2021

Vertebrate Scavenger Diversity And Ecosystem Services Along An Elevational Gradient In Central Nepal, Aishwarya Bhattacharjee

Dissertations, Theses, and Capstone Projects

A growing number of studies recognize the ecological significance of vertebrate scavengers, and several species belonging to this diverse, functional guild are of high conservation importance around the globe. Studies on taxonomic and functional components of biodiversity often use elevation gradients to comprehensively examine patterns and drivers across multiple spatial scales. Yet, there are relatively few elevational studies on large vertebrates or multi-taxa guilds, and the related variation of their ecosystem services. In particular, scavenger research has largely focused on local-scale studies or regional/global comparisons of local-scale investigations. Moreover, these studies primarily consider taxonomic community characteristics and the patterns of …


Habitat Use And Morphology Of Birds In "Intact" Amazonia Under Changing Climate, Vitek Jirinec Jul 2021

Habitat Use And Morphology Of Birds In "Intact" Amazonia Under Changing Climate, Vitek Jirinec

LSU Doctoral Dissertations

Neotropical forests contain the core of global avian diversity. Of these, the Amazon rainforest is the largest, but ~20% has already been lost to deforestation, inspiring research into the effects of clearing and fragmentation on forest birds. These studies have consistently shown that insectivorous birds that forage on or near the ground are the most sensitive species to forest disturbance. As a preamble to our study, we synthesized bird capture data collected over 40 years within continuous forest far from human disturbance. Remarkably, we found that terrestrial and near-ground insectivores have shown substantial abundance declines even within primary forest. The …


Food Caching Decisions In Canada Jays (Perisoreus Canadensis), Robert J. Martin Jun 2021

Food Caching Decisions In Canada Jays (Perisoreus Canadensis), Robert J. Martin

Electronic Thesis and Dissertation Repository

Food scarce periods pose serious challenges for birds, particularly when those periods coincide with demanding life history stages such as overwintering. For resident birds in the Northern hemisphere, resource scarcity typically occurs simultaneously with winter conditions. In order to combat these compounded stressors, some species cache food to ensure a reliable supply of resources. Food caching is the storing of food items for subsequent retrieval and consumption after some delay. Canada Jays (Perisoreus canadensis) are year-round residents of the North American boreal forest and some high elevation areas in the United States, and cache food to combat resource …


Ecology Of Estuarine Birds: Differences In Desensitization Of Year-Round And Transient Species, Sarah Thomas May 2021

Ecology Of Estuarine Birds: Differences In Desensitization Of Year-Round And Transient Species, Sarah Thomas

Honors Theses

Huntington Beach State Park in Murrells Inlet, SC, USA is considered a “hotspot” for birds, according to the eBird database (eBird, 2020). The park is also visited by approximately 300,000 people, annually (Hobdy, 2019). The causeway at the park is an area of high human and wildlife activity. Here, the differences in desensitization, or lack thereof, of year-round and transient bird species to the stimuli of vehicles and humans were determined. Multiple surveys of the birds at Huntington Beach State Park were conducted from 22nd September, 2019 to 13th June, 2020. Desensitization was quantified by use of a range finder …


The Effects Of Urbanization On The Avian Gut Microbiome, Mae Berlow May 2021

The Effects Of Urbanization On The Avian Gut Microbiome, Mae Berlow

Doctoral Dissertations

The gut microbiome influences and is influenced by the host, and can affect the host organism by contributing to health, development and immunity. Similarly, the host can influence this community; it’s makeup can vary with host species, locality, diet, social stressors, and environmental stressors. Some of these environmental stressors have arisen due to human-induced rapid environmental change, like urbanization. The physiology and behaviors of organisms that are able to persist in urban environments are often different from their non-urban congeners. Nutrition, development, and immunity—all of which are affected by the gut microbiome—are important factors that can determine survival in urban …


Overwinter Ecology Of Rusty Blackbirds (Euphagus Carolinus) In Arkansas, Araks Ohanyan Apr 2021

Overwinter Ecology Of Rusty Blackbirds (Euphagus Carolinus) In Arkansas, Araks Ohanyan

ATU Theses and Dissertations 2021 - Present

Rusty Blackbirds are one of the most rapidly declining songbirds in North America. They have lost an estimated 85-95% of their population since the 1960s. Unfortunately, we currently do not know what is causing their decline. However, since habitat alteration and loss in their nonbreeding range has been much more severe than in their breeding range, many think the decline is associated with winter habitat loss. Consequently, knowledge of winter ecology, with a focus on habitat use and selection, may provide management insights useful for reversing the decline. My field assistants and I (hereafter we) used radio telemetry to collect …


Population Dynamics And Dispersal Coalitions In The Cooperatively Breeding Acorn Woodpecker, Natasha Hagemeyer Apr 2021

Population Dynamics And Dispersal Coalitions In The Cooperatively Breeding Acorn Woodpecker, Natasha Hagemeyer

Biological Sciences Theses & Dissertations

Dispersal is a critical life-stage with consequences not only for the individual, but for population dynamics and thus the fate of the whole species. The creation of dispersal coalitions can lead to complex outcomes and affect how changes in abundance occur on the landscape. I examined population dynamics and dispersal coalitions in a population of cooperatively breeding acorn woodpeckers in central California, USA. Using a 34-year dataset on occupancy and abundance, I determined that increases in abundance were determined by dispersal to new locations. This resulted in increased occupancy, rather than increases in group size and larger coalitions. I then …


Avian Attractiveness To Vertically Polarized Light, Aurora Belle Kuczek Jan 2021

Avian Attractiveness To Vertically Polarized Light, Aurora Belle Kuczek

Senior Projects Spring 2021

It is well-known that many animal species can detect polarized light cues of water and water-like objects in the visible and ultraviolet range. However, studies investigating if birds can see polarized light in field-based settings are rare. Furthermore, no studies have yet been conducted to understand avian attractiveness to vertically polarized light, nor have studies considered other natural polarizers of light such as tree sap. I designed a choice-field experiment to investigate if birds can detect, and are attracted to vertically polarized light. First, I cut six pieces of clear vinyl into a foot by 54 inches. I painted each …


Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin Jan 2021

Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin

Theses and Dissertations

Understanding habitat selection at multiple scales is an important step in guiding conservation programs and reversing species declines. This, however, is difficult for species that occupy early-successional habitats (ESH) due to a lack of accurate representation of shrub cover in publicly available land cover data. The Golden-winged Warbler (Vermivora chrysoptera; GWWA) is a threatened species of conservation concern and a flagship for ESH conservation. We used a novel, LIDAR-derived land cover classification that accurately identifies shrubs at a fine resolution (1m) to investigate how habitat composition and configuration influence GWWA site occupancy. We aggregated this same land cover …


Predation Threat In A Variable Landscape: Connecting Predation Risk To Nesting Success For The Seaside Sparrow (Ammospiza Maritima Macgilivraii), Corina D. Newsome Jan 2021

Predation Threat In A Variable Landscape: Connecting Predation Risk To Nesting Success For The Seaside Sparrow (Ammospiza Maritima Macgilivraii), Corina D. Newsome

Electronic Theses and Dissertations

Predation, the leading cause of nest-failure in birds, not only exists as a direct threat to nesting success, but may exacerbate other sources of nest mortality. Birds inhabiting Atlantic coastal marshes, such as Seaside Sparrows (Ammospiza maritima; hereafter SESP), are experiencing significant and rapid changes to their habitat, particularly sea level rise (SLR) and encroaching urbanization, that may affect the relative influence of nest predation on overall productivity. For SESPs, SLR presents an inherent threat to nest success in its potential to increase the frequency of nest flooding. In addition to this direct threat, the ability of SESPs …


Effects Of Predator Management And Parasitism On Over-Water Nesting Diving Duck Production In Southwestern Manitoba, Trenton E. Rohrer Jan 2021

Effects Of Predator Management And Parasitism On Over-Water Nesting Diving Duck Production In Southwestern Manitoba, Trenton E. Rohrer

Electronic Theses and Dissertations

Nest survival of upland nesting waterfowl (e.g., mallard [Anas platyrhynchos], blue-winged teal [Anas discors]) has been studied extensively in the Prairie Pothole Region (PPR) of North America. Conversely, over-water nesting diving ducks’ nest survival is poorly understood, likely because over-water nests are more challenging to find, may be less concentrated, and searching for these nests is physically demanding. Nest depredation is considered a leading cause of duck nest failure and is considered a limiting factor on upland nesting waterfowl production in the PPR. Similar factors limiting upland nesting duck production may limit over-water nesting duck productivity, but studies of this …


Response Of Forest Birds To Spotted Wing Drosophila (Drosophila Suzukii Matsumura), A Novel Invasive Fruit Pest, At Allegheny National Forest, Daniel P. Roche Jan 2021

Response Of Forest Birds To Spotted Wing Drosophila (Drosophila Suzukii Matsumura), A Novel Invasive Fruit Pest, At Allegheny National Forest, Daniel P. Roche

Graduate Theses, Dissertations, and Problem Reports

Non-native invasive insect pests can have dramatic impacts on native ecosystems, feeding on plant foliage, wood, or sap. Little is known, however, about how fruit-targeting NNIIPs may affect native ecosystems. Spotted wing Drosophila (Drosophila suzukii Matsumura, SWD) is a recently introduced invasive vinegar fly that parasitizes the fruits of many plant species in the United States. While its activity in agricultural systems is well-documented, little is known about its activity in forest ecosystems, despite growing evidence of its presence and parasitism of fruits there. Parasitism could reduce fruit attractiveness for vertebrate fruit consumers, including migratory birds. As such, this …