Ecology and Evolutionary Biology Commons^™

Assessing The Role Of The Microbiome, Parasite Infections, And Movement In Avian Health, Olivia N. Choi

Electronic Theses and Dissertations

Avian health encompasses the physical, physiological, and behavioral well-being of birds. Assessing avian health is not only important for the conservation and management of wild birds and the recreational economy, but also for the management of infectious diseases that threaten public health and agriculture. Birds, comprising approximately 10,000 species and an estimated 50 billion individuals worldwide, are known to be involved in the spread of pathogens, some of which are zoonotic (from animals to humans), such as avian influenza and West Nile viruses. Individual measures of avian health may include physical measurements (e.g., body mass, wing length), pathogen infection status, …

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Rusty Blackbird Use Of Commercial Spruce-Fir Forests Of Northern New England, Luke M. Douglas

Electronic Theses and Dissertations

The Rusty Blackbird (Euphagus carolinus) has experienced a steep population decline since the 1970s, with qualitative accounts suggesting that the species’ numbers have been falling prior to the 1950s. The reason for this decline is still not fully understood, though recent work suggests that habitat destruction and disturbance in the breeding and wintering ranges are likely causes. The species is a habitat specialist that relies on spruce-fir stands located near wetlands for breeding in the boreal and Acadian forests of North America. Historically, the natural disturbance regime in the Acadian region included biotic agents such as beaver and …

Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura

Electronic Theses and Dissertations

The tallgrass prairie of North America has changed drastically since colonial settlement, with up to 99% of this region converted for agriculture and other land-uses. Concurrent with grassland conversion, grassland birds have experienced the most extreme, consistent, and widespread population declines of any avian guild. Agricultural lands in the U.S. Midwest were able to provide adequate habitat for several bird species until the 1950’s; however, altered and intensified management practices have degraded much of remaining suitable habitat and undermined ecosystem functions. Consequently, many grassland birds have been identified as Species of Greatest Conservation Need (SGCN) in many State Wildlife Action …

Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor

Electronic Theses and Dissertations

The Prairie Pothole Region (PPR) of North America provides critical habitat for waterfowl across life stages, but anthropogenic changes to the landscape have negatively impacted habitat quality for waterfowl. The mallard (Anas platyrhynchos) is abundant and socioeconomically valuable in the PPR, as it is a preferred target species of waterfowl hunters. Extensive research has evaluated breeding ecology of mallards in the PPR, but the period between juvenile mallards fledging and migrating has rarely been studied. The post-fledging ecology of juvenile mallards is a vital consideration for comprehensive waterfowl management. Further, juvenile mallards are a significant portion of hunter harvest at …

Epigenetic Buffering In Introduced House Sparrows, M. Ellesse Lauer

Electronic Theses and Dissertations

Epigenetic buffering, as an environmentally induced increase in variance of epigenetic states that increases phenotypic variation to buffer populations against decreased fitness, may be a factor that resolves the genetic paradox of introduced species. DNA methylation is a molecular mechanism that could facilitate epigenetic buffering by changing in response to environmental stress. Therefore, epigenetic buffering can be detected through increased variance in DNA methylation in novel or heterogeneous environments. Introduced house sparrows (Passer domesticus) have well-documented phenotypic changes with low genetic diversity, high epigenetic diversity, and high variance in DNA methylation that provide a characteristic signature of epigenetic buffering. …

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

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 …

Glare Reduction By Dark Facial Markings And Bills In Birds, Clara Lebow

Electronic Theses and Dissertations

Avian facial plumage, bill coloration, and feather microstructure may serve one or more adaptive functions. Several researchers have proposed that dark eyestripes, bills, and facial masks aid in reducing glare, however, there have been relatively few tests of this hypothesis. Dark facial markings have been shown to have an adaptive glare-reduction function in recent field studies of a few species, but this hypothesis has never been tested in a broad multispecies analysis. It is likely that feather microstructure influences feather brightness and has an effect on the efficacy of glare reduction properties of feathers. I examined the link between dark …

Understanding How Agricultural Intensification Impacts Ring-Necked Pheasant Distribution And Survival In Eastern South Dakota, Hilary R. Kauth

Electronic Theses and Dissertations

Historically, pheasants (Phasianus colchicus) have thrived in South Dakota in conjunction with successful land retirement programs or early farming practices through the 1950s, which created interspersions of agriculture and native landscapes that were ideal for pheasants. Recently, the Prairie Pothole ecosystem has undergone rapid agroeconomic expansion, effectively reducing ideal interspersions of native prairie and cropland into agriculturally homogeneous landscapes. Indices of pheasant abundance have suggested persistent population declines since 2008, raising concerns regarding landscape suitability. Our goal was to understand how agriculture intensification impacts pheasant ecology. The objectives were to: 1) estimate overwinter hen probability of survival, resource …

Winter Patch Grazing, Patch Burn Grazing, And Bird Communities In Western South Dakota, Jennifer Lutze

Electronic Theses and Dissertations

Ground nesting bird species are on a considerable decline and research efforts are being made to increase these populations throughout the Great Plains. Ground nesting bird communities found in the Northern Great Plains are driven greatly by varying amounts of cover and area size. Past research implemented patch-burn grazing to increase structural heterogeneity and to increase grassland bird habitat in the tallgrass prairie. While bird populations were very responsive to this management in the Northern Great Plains fire management is viewed negatively, especially for Midwest cattle ranchers. We implemented research to determine if winter-patch grazing on mixed grass prairie could …

Niche Evolution Along A Gradient Of Ecological Specialization, Meaghan Conway

Electronic Theses and Dissertations

The concept of the ecological niche is fundamental to understanding constraints on species distributions in space and time, and in explaining the origin and maintenance of biodiversity. A niche can be broadly defined to include all of the biotic and abiotic conditions that a species requires to persist. Niche breadth, or the degree of specialization, may influence how labile a species niche is, which can have broad implications for species ability to adapt to environmental change, and for explaining patterns of diversification. I investigated mechanism that facilitate or constrain niche evolution at multiple scales. First, I developed an index of …

Associations Between Avian Spruce-Fir Species, Harvest Treatments, Vegetation, And Edges, Brian W. Rolek

Electronic Theses and Dissertations

Habitat loss is the primary cause of species loss and declines of global biodiversity. Several birds associated with the spruce-fir forest type (hereafter spruce-fir birds) have declining populations across the continent in the Atlantic Northern Forest, and the extent of coniferous forest has declined in some areas. This region is extensively and intensively managed for timber products.

To investigate the influence from harvest treatments on the spruce-fir bird assemblage during the breeding and post-breeding period in lowland conifer and mixed-wood forests, we used avian point count detection data to test for associations between avian assemblages and seven common harvest treatments. …

Breeding Bird Response To Post Oak Savanna Restoration Seven Years Post Management In Eastern Texas, Courtney Mcinnerney

Electronic Theses and Dissertations

Oak savannas were once an abundant vegetation type in the Midwestern United States that have now declined to <1% of their original distribution. Historically, natural disturbances such as periodic fire and grazing maintained oak savannas, but these have been reduced or eliminated, resulting in woody encroachment and subsequent habitat loss and degradation. In 2009-10, a baseline, pre-restoration study was completed to determine vegetation characteristics, breeding bird abundances, nest success, and nest site selection at the Gus Engeling Wildlife Management Area (GEWMA) in eastern Texas. The results showed a lack of savanna vegetation structure on degraded sites and few savanna or grassland obligate bird species. The goal of this study was to determine how breeding birds of oak savanna vegetation types in eastern Texas respond to restoration effects 7 years after initial management. Post-restoration surveys completed in 2016-17 showed a change in avian assemblages from a more woodland dominated community to grassland/savanna community. The presence and breeding of savanna obligate species dickcissel (Spiza americana) and lark sparrow (Chondestes grammacus) indicates that the restoration was successful. The presence of savanna species can be linked to the herbaceous vegetation that was restored to more closely resemble historic oak savanna structure and can quantify the success of restoration efforts.

Behavioral Ecology Of Landbird Migrants In A Complex And Changing Flyway System: The Gulf Of Maine, Adrienne J. Leppold

Electronic Theses and Dissertations

In and around the Gulf of Maine, over 300 species of birds have been documented during migration, and tens of millions of songbirds may pass through the region on a single autumn night. Shorelines are widely documented as major migration corridors. There is ample evidence that coastal areas concentrate migrants and many species make overwater movements to and from breeding and wintering grounds. Data collected from radar, banding, and ceilometry studies in the northeast have provided us with evidence that birds migrate along the coast and make overwater movements across the Gulf of Maine and Bay of Fundy during both …

The Nutritional Value Of Fecal Sacs: Testing The Parental Nutrition Hypothesis, Amanda W. Burns

Electronic Theses and Dissertations

Nest sanitation is an important aspect of parental investment in birds with altricial nestlings. Passerine nestlings produce fecal matter that is encased in a mucous membrane for easy disposal. These fecal sacs are either removed from the nest and transported a distance away or they are ingested by the adult. A decline in fecal sac ingestion rates as nestlings age has been observed in several species. The parental nutrition hypothesis posits that this pattern can be attributed to increasing digestive efficiency as nestlings age. The parental nutrition hypothesis makes three predictions: fecal sac consumption rates should decrease as nestlings age, …

The Winter Ecology Of The Piping Plover (Charadrius Melodus) In Coastal Georgia, Brandon Lennon Noel

Electronic Theses and Dissertations

Author's abstract: The Piping Plover (Charadrius melodus) is a federally listed species with three distinct breeding populations, including Great Plains (threatened), Great Lakes (endangered), and Atlantic Coast (threatened), all of which winter along the Atlnatic and Gulf coasts of the United States. I studied the winter ecology of the Piping Plovers on Little St. Simons Island (LSSI), Georgia, from 2003-2006, with emphasis on the conservation significance of this site for the endangered Great Lakes population. During 2003-2004 and 2004-2005, LSSI supported up to 100 Piping Plovers during peak migration, and approximately 40 birds wintered at this site. All populations had …