Ecology and Evolutionary Biology Commons^™

Effects Of Habitat Selection And Individual Quality On The Reproductive Success Of Barn Owls (Tyto Furcata), Jaime E. Carlino

Cal Poly Humboldt theses and projects

The hypothesis of adaptive breeding habitat selection proposes congruence between the evolved selection of habitats and fitness components such as reproductive success. However, mismatches between habitat selection and observed fitness outcomes are not unusual and can arise for multiple reasons. Variation in individual qualities of animals has also been found to affect reproduction and survival. I examined associations between barn owl nest box selection, reproductive output, and plumage characteristics previously shown to correspond to individual quality. I found that barn owls selected tall nest boxes made of wood, mounted high off the ground, and with increased proportions of grassland around …

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, …

Characterization Of Antimicrobial Properties Of Excrement And Functional Microbiome Of Black Vultures (Coragyps Atratus), Bridgette Gray

Theses

Black vultures, Coragyps atratus, are obligate scavenging birds that consume and dispose of decaying carcasses and carrion. They fulfill a key ecological niche in the environments in which they live. It has been observed that these vultures sometimes excrete bodily waste onto their legs. This adaptive behavior could help aid them in controlling bacteria and other microbes they encounter while stepping into a carcass to eat. This study directly examined the antimicrobial properties of the excrement of black vultures across various bacterial species utilizing a zone of inhibition test and a nematode species utilizing a survival assay. The black vulture …

Statistical And Biological Analyses Of Acoustic Signals In Estrildid Finches, Moises Rivera

Dissertations, Theses, and Capstone Projects

Acoustic communication is a process that involves auditory perception and signal processing. Discrimination and recognition further require cognitive processes and supporting mechanisms in order to successfully identify and appropriately respond to signal senders. Although acoustic communication is common across birds, classical research has largely disregarded the perceptual abilities of perinatal altricial taxa. Chapter 1 reviews the literature of perinatal acoustic stimulation in birds, highlighting the disproportionate focus on precocial birds (e.g., chickens, ducks, quails). The long-held belief that altricial birds were incapable of acoustic perception in ovo was only recently overturned, as researchers began to find behavioral and physiological evidence …

Relationships Between Behavior, Energy Metabolites, And Corticosterone In Black-Legged Kittiwake (Rissa Tridactyla) Nestlings, Sierra Pete

Master’s Theses

Birds can cope with energy-shifting challenges by redirecting energy and behavior to maintain energetic homeostasis. Nestlings allocate energy to support their rapid growth and developmental period; thus, their challenges and the subsequent energetic demands can be much different than an adult. At a baseline level, energy is constantly shifting in response to regularly occurring challenges; however, more substantial challenges can initiate the production of glucocorticoid hormones. In birds, the main glucocorticoid is corticosterone. Corticosterone is believed to aid in energy homeostasis by redirecting energy metabolite mobilization. Energy metabolites are intermediaries or end products of cellular metabolism, thus, metabolites like glucose …

Assessing Forest Features And Nocturnal Flying Insect Diversity As Predictors Of Eastern Whip-Poor-Will Occupancy In Foraging Habitat, Clark D. Alexander

Graduate Theses, Dissertations, and Problem Reports

Eastern whip-poor-will (Antrostomus vociferus), an insectivorous caprimulgid, have seen an approximate 2.76% annual population decrease since the 1960s, with their breeding and foraging ecology largely unknown due to their nocturnal and cryptic behavior. I conducted research to assess abiotic and biotic variables correlated with detection, and occupancy probability, and prey species diversity on ~104,000 hectares of forest in West Virginia, owned by the private timber company Weyerhaeuser. Previous literature indicates that Eastern whip-poor-will, and their prey, require ephemeral habitat such as recently cleared and early successional forests, like those historically created by forest fires, wind shears, hurricanes, and …

Quantifying Insect Emergence In Tidal Freshwaters And The Importance Of Aquatic Prey In Wetland-Dependent Songbird Diet, Samantha L. Rogers

Theses and Dissertations

Insectivorous birds and their arthropod prey are experiencing widespread population declines, driven largely by anthropogenic disturbance and climate change. For wetland-dependent insectivores that consume a mixture of terrestrial and aquatic insects, understanding the availability, consumption, and nutritional qualities of aquatic diet subsidies is important for conservation. I use prothonotary warblers (Protonotaria citrea) as a model species throughout this work, because their breeding season aligns with aquatic insect emergence and they include aquatic insects when provisioning nestlings. In the first chapter, I estimate aquatic insect emergence from tidal freshwaters, which are understudied compared to nontidal systems. Using continuous field …

Eavesdropping On Animals: Can Bioacoustics Help Save Species?, Zoe Grueskin

Capstones

Around the world, scientists are using sound to study the natural world in a growing field called bioacoustics. Researchers are eavesdropping on frogs and fish, elephants and earthworms, and many hope what they hear can inform and inspire conservation action around the world. From the field’s auspicious beginning with accidentally-recorded whales, to researchers today listening to locations as diverse as the Arctic seafloor and India’s Western Ghats mountain range, this capstone project explores the potential — and limitations — of conservation bioacoustics. Read the story, see photos and listen to audio pieces featuring three bioacousticians and their field recordings here: …

Temperature Affects Nest Box Occupancy, Nest Success, And Nestling Size In A Southeastern Population Of Eastern Bluebirds (Sialia Sialis), Christopher G. Horacek

Biology Theses

Given the critical role that temperature plays in avian reproductive biology, rising temperatures as a result of global climate change will likely impact reproductive success of many bird populations. Secondary cavity nesting birds, many of which rely on artificial nest boxes to maintain population levels, may be particularly at risk because increased temperatures inside nest boxes can determine whether nest boxes are selected, reduce nest success, and/or negatively affect the growth and survival of offspring. We examined the effect of nest box color on nest box temperature and the influence of nest box temperature, nest box color, entrance orientation, and …

The Role Of Nest Location On The Reproductive Success Of Piping Plovers Breeding At Rockaway Beach, New York, Clara I.D. Arndtsen

Theses and Dissertations

The study’s goal was to learn what aspects of the piping plover experience affect reproductive outcomes at Rockaway Beach Endangered Species Nesting Area. Nest location was found to help predict reproductive success. Nests further from American oystercatcher nests were likely to fledge more chicks. Reproductive success was low in 2021.

Insights Into The Speciation Process From Genomic And Phenotypic Analysis Of An Avian Hybrid Zone In Amazonia, Glaucia Christina Del-Rio

LSU Doctoral Dissertations

Understanding the outcome of secondary contact is essential to shed light on the mechanisms governing species formation and maintenance. In Amazonia, closely related bird taxa with limited dispersal abilities are often separated by rivers, which presumably act as dispersal barriers. However, at the headwaters, rivers cease to be dispersal barriers, and this generates opportunities for secondary contact. In my dissertation, I studied genomic mechanisms associated with phenotypic differences, mitochondrial DNA structure, and putative reproductive barriers between two hybridizing Amazonian bird species in the genus Rhegmatorhina, a group of antbirds that find their arthropod prey exclusively by following army-ant swarms. …

Breeding Ecology Of Mottled Ducks In Southwestern Louisiana, Elizabeth Sophia Bonczek

LSU Doctoral Dissertations

Mottled ducks are a resident species found in the southern United States that rely on coastal marsh and associated habitat to fulfill the needs of the entirety of their annual cycle. Population monitoring has revealed declines in western Gulf Coast (WGC) mottled ducks since 2008. Mottled duck populations are influenced by survival and recruitment, and changes in these factors may contribute to population declines. The overarching goal of this project was to identify the mechanisms potentially limiting WGC mottled ducks.

I captured adult female mottled ducks during molt on Rockefeller Wildlife Refuge and adjacent lands in southwestern Louisiana from 2017–2019. …

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 …

Nesting Ecology Of Wood Ducks And Other Cavity-Nesting Ducks In Mississippi, Justin Taylor Gibson

Theses and Dissertations

Man-made nest boxes are surrogate nest sites widely used by waterfowl managers in North America to propagate free-ranging Wood Ducks (Aix sponsa) and other cavity-nesting waterfowl. I monitored 129 and 174 nest boxes in 2020 and 2021, respectively, at Noxubee National Wildlife Refuge and York Woods, Mississippi. I evaluated site-specific biotic and abiotic factors that were potentially influential on nest survival of Wood Ducks and general nesting ecology and apparent nest success of Black-bellied Whistling Ducks (Dendrocygna autumnalis) and Hooded Mergansers (Lophodytes cucullatus). Daily survival rate of Wood Ducks was negatively influenced by increasing encroaching vegetation at Noxubee NWR and …

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 …

Songbird-Mediated Insect Pest Control In Low Intensity New England Agriculture, Samuel J. Mayne

Masters Theses

Global agricultural intensification has caused large-scale wildlife declines, but agricultural lands that maintain natural habitats can support healthy wildlife populations and receive significant ecosystem services from these natural communities. However, how on-farm biodiversity results in beneficial ecosystem services is highly variable and is reported to differ among taxa and guilds. One group that has attracted attention for their potential beneficial role in reducing pest abundance are birds. Understanding the role of bird communities and individual species in pest control could be important for managing farms under a low intensity agroecological framework. In New England, farmers are increasingly applying low intensity …

Drivers And Direct Impacts Of Lean Mass Dynamics On The Stopover Ecology And Migratory Pace Of Nearctic-Neotropical Migrant Songbirds In Spring, Mariamar Gutierrez Ramirez

Doctoral Dissertations

Annual migration in songbirds is one of the most demanding life-history stages. It represents a period of high mortality, yet there is still much unknown about the ecological correlates that influence its successful completion. After long non-stop migratory flights, birds require a stopover period to rest and replenish depleted energy reserves. Birds use fat as the primary fuel to power long-distance flights. However, birds also burn lean tissue, which results in significant reductions in muscle and organ masses. The discovery and quantification of lean mass catabolism represented a paradigm shift in migration ecology because non-fat components were thought to remain …

Display Site Selection By Male Ruffed Grouse In The Upper Great Lakes Region, Seth Finkel

Dissertations, Master's Theses and Master's Reports

The Ruffed Grouse (Bonasa umbellus) is widely known for its characteristic territorial drumming display. In this study, I used ruffed grouse drumming survey data from Minnesota and Michigan, in a series of mixed logistic models, to identify drivers of drumming log selection by reproductive male ruffed grouse. I collected drumming stage data utilizing a paired-random sampling structure. I used information theoretic model selection to examine three sets of a priori mixed logistic models: one for the entirety of my Minnesota dataset, one consisting of stages identified in aspen stands in Minnesota, and one for my Michigan dataset. In …

Conservation Value Of Working Landscapes In Mesoamerica For Nearctic-Neotropical Migratory Birds, Samuel L. Oliveira

Dissertations, Master's Theses and Master's Reports

Populations of many of Nearctic-neotropical migratory birds have declined in the past several decades, recent estimates suggested a dramatic loss of 2.5 billion birds over the past 50 years in North America. Habitat loss and degradation represent a major threat in the tropics. Managed agroecosystems have the potential to mitigate some impacts of land conversion, however, little is known regarding the habitat quality provided by working landscapes in the overwintering range. In this research, we surveyed the migratory bird community in the rapidly expanding oil palm plantations in southern Mexico; and also the declining population of the Wood Thrush ( …

Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein

Theses and Dissertations

In this study I attempted to further resolve the population genetic structure in the Prothonotary Warbler (Protonotaria citrea), and conducted an outlier SNP analysis and exploratory gene ontology analysis to investigate potential ongoing natural selection in the species. This analysis of population structure confirms previous work by DeSaix et al. (2019), where weak population structure was observed between eastern sites along the Atlantic Coastal Plain, and western sites in the Mississippi Alluvial Valley, possibly due to a genetic discontinuity across the Appalachian Mountains. I conducted two forms of outlier SNP analyses, a principal component analysis (PCA)-based approach to identify SNPs …

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. …

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 …

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

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 …

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

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

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

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

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 …