Doctor of Philosophy (Ph.D.), Bowling Green State University, 2018, Biological Sciences

Many long-distance migratory songbirds encounter geographic barriers at some point during their annual migrations. Bird migration routes often follow detours where passages across ecological barriers are either avoided entirely or reduced in extent. Numerous early reports of broad front migration crossing coastlines seemingly without taking notice of the transition from land to water contradict more recent observations suggesting important deviations from the standard broad front direction associated with the underlying topography, in particular, the course of coastlines. However, whether and under what conditions nocturnally migrating songbirds would respond to a more modest obstacle such the Great Lakes is less well understood. I used a combination of weather surveillance radar and thermal imaging cameras to capture the direction of spring migration both regionally, as migrants are approaching the southern shore of Lake Erie, and locally along the coast. In the present body of work, I have studied (1) the nocturnal migratory orientation of birds along the southwest coast of Lake Erie during the spring migratory season, (2) the orientation of migrants with respect to the prevailing winds, and (3) the orientation with respect to time of night, which presumably is reflective of differences in the energetic condition of migrants. Along the southwest coast of Lake Erie, the direction of migration differed significantly from the broad front direction approaching Lake Erie, and the probability of a migrant deviating from the broad front direction was higher at sites which presented southeast-northwest oriented coastlines (Cedar Point and Ottawa NWR). Even under energetically favorable winds above Cedar Point and Ottawa some migrants were observed detouring the Lake, and migration in crosswinds increased the likelihood of either coastal flights in easterly winds or crossing flights in westerly winds. Migrants approaching the shore above Ottawa showed a significant increas (open full item for complete abstract)

Committee: Verner Bingman Ph.D. (Advisor); Jon Sprague Ph.D. (Other); Andrew Gregory Ph.D. (Committee Member); Kevin McCluney Ph.D. (Committee Member); Daniel Wiegmann Ph.D. (Committee Member) Subjects: Biology; Ecology; Zoology

Master of Science (MS), Bowling Green State University, 2024, Biological Sciences

In birds, the adaptive significance of group-living has promoted considerable debate about the potential role of environmental drivers in the evolution of coloniality. Nest aggregations may result as a plastic response of reproductive individuals to limited substrate availability and favorable environmental conditions for nesting (Limited Substrate Availability Hypothesis). In contrast, nest aggregations may result as an evolutionary consequence of adaptive benefits derived from social interactions or intrinsic traits of individuals nesting in groups (Social Adaptation Hypothesis). A population survey of the Chimborazo Hillstar, Oreotrochilus chimborazo chimborazo, a hummingbird species from the High Andes, resulted in the identification of 7 nesting aggregations and 13 solitary nests, with most nests (82%) found in reproductive colonies. Furthermore, nesting aggregations were all consistently associated with roosting groups of non-reproductive individuals, a unique case among birds. The predominance and temporal stability of nest aggregations indicate that colonial nesting represents the main reproductive strategy for this hummingbird. The characterization of Chimborazo Hillstar nesting habitat revealed that temperature, wind speed, and humidity, and landscape features associated with substrate availability, ground cover vegetation, and water represent important environmental drivers of nesting aggregations, consistent with the Limited Substrate Availability Hypothesis. However, a semi-natural experiment comparing occupancy and success of nesting aggregations versus solitary nesting revealed that only 31.8% of the sites available for solitary nesting had one active nest with a female brooding its clutch, whereas nesting aggregations consistently had multiple active nests producing broods across multiple reproductive seasons. The unique co-occurrence of nesting and roosting groups in the Chimborazo Hillstar suggests that the species social context may have p (open full item for complete abstract)

Committee: Juan Bouzat Ph.D. (Committee Chair); Verner Bingman Ph.D. (Committee Member); Daniel Wiegmann Ph.D. (Committee Member) Subjects: Biology; Ecology; Evolution and Development

Doctor of Philosophy, University of Toledo, 2021, Biology (Ecology)

Conserving and managing migratory species is inherently complicated due largely to their reliance on multiple landscapes at different stages of their annual cycle. The combination and degree to which each life stage (e.g., nascence through independence from adult care), geographical location (e.g., a large estuarine stopover site), or portion of the annual cycle (e.g., the nonbreeding period) influences a population is often unknown. Thus, resulting conservation strategies are often built with information representing a limited portion of a migratory species' annual range. This trend is concerning as recent studies demonstrate the influence of poorly studied life stages (e.g., the post-fledging period) and carryover effects (e.g., habitat quality and food availability influencing subsequent productivity) on population dynamics of migratory species. Previous research suggests that, like other migratory taxa, global populations of many migratory birds are declining at alarming rates, presenting an important and time-sensitive opportunity to develop full life-cycle conservation strategies and identify and mitigate key factors driving population declines in migratory species. This dissertation investigates the migratory ecology of Vermivora warblers and synthesizes findings in ecological, evolutionary, and conservation frameworks. Vermivora warblers are a species complex composed of two extant species of obligate Nearctic-Neotropical migrant warblers that are extremely closely related. Golden-winged warblers (Vermivora chrysoptera) and blue-winged warblers (Vermivora cyanoptera) breed and migrate throughout deciduous forests of eastern North America and occur throughout Central America, with golden-winged warblers also occurring in northern South America during the nonbreeding period. On the breeding grounds, golden-winged warblers and blue-winged warblers have overlapping distributions and regularly hybridize to produce viable young. Recent genomic evidence suggests (open full item for complete abstract)

Committee: Henry Streby (Advisor); David Andersen (Committee Member); Petra Wood (Committee Member); David Buehler (Committee Member); Jon Bossenbroek (Committee Member) Subjects: Animals; Biology; Ecology; Environmental Science; Wildlife Conservation; Zoology

Master of Science (MS), Bowling Green State University, 2020, Biological Sciences

Migrating passerines (Passeriformes) can travel thousands of kilometers to reach their summer and winter grounds, and while migrating, they encounter environmental barriers like mountains, deserts, and oceans, which force birds to decide whether to continue in the typical migratory direction or deviate around the barrier. Hundreds of species of migrants utilize the Mississippi Flyway, which may involve encountering the Great Lakes including the southwestern coast of Lake Erie. Gesicki et al. (2019) found that during Spring migration many migrants deviated westwards along the southern coast of Lake Erie instead of crossing the lake along their same heading. The goal of the current study was to determine whether migrants arriving at the Ohio coast of Lake Erie in the Fall, after crossing the lake, would similarly respond to the coastal features of Lake Erie's Ohio coastline as they do in Spring. Specifically, would migrants display deviated flight directions with respect to the coastline at three observation sites as well as compared to the broad front direction of migration recorded by Doppler weather radar in Cleveland? This was determined by comparing individual flight directions recorded from three sites, Cedar Point, Ottawa, and Maumee Bay, as well as the nightly, broad front direction recorded at Cleveland. Across a number of analyses, no meaningful differences in migratory flight directions were observed across the three observation sites nor with respect to the broad front direction recorded by Doppler weather radar. Generally, migrants flew in a south-southwesterly direction irrespective of location. As a separate analysis, no differences were found in the flight directions of migrants when birds observed early in the night were compared against birds observed later in the night. In summary, and in contrast to the Spring (Gesicki et al, 2019), migrant songbirds reaching the southern coast of Lake Erie in Fall do not appear to respond to coastline features (open full item for complete abstract)

Committee: Verner Bingman Dr. (Advisor); Kevin Neves Dr. (Committee Member); Daniel Wiegmann Dr. (Committee Member) Subjects: Biology; Environmental Science

Doctor of Philosophy, Miami University, 2018, Ecology, Evolution and Environmental Biology

Citizen science has broadened the scope of biodiversity monitoring and research. Citizen scientists visit more locations, more often and collect data on more species than any single study can. They have fewer restrictions related to funding, scheduling and political will. They create more data than ever before, especially in remote locations such as Small Island Developing States (SIDS). However, citizen science uses traditional science perspectives in data analysis; acknowledging the perspectives of the citizen scientist is important when making conservation decisions based on citizen science data. I use novel perspectives that make citizen science data more useful/powerful. I focus on 16 native bird species and 20 migrant species of international concern using volunteer observations from the open access eBird database. Using forestry maps and satellite data, I created a new, adaptable, classified habitat map for Grand Bahama and appended the habitat data to eBird observations for the island. Observer effort was significantly higher in beach and grass habitats. I found most of the focal species in this study outside their documented habitat type. Bird species richness and observer richness differed significantly among habitat types. Bird species composition was significantly influenced by habitat type and survey effort. Mantel tests showed significant correlation between geographic locations and both bird species dissimilarity and observer dissimilarity. The Mantel tests also showed significant correlations between observer community differences and species community differences. I used Moran's I to determine spatial autocorrelation of observer effort and recorded species diversity within the dataset. Observer richness and the total number of surveys were negatively spatially autocorrelated in the overall dataset. I found that observer community similarity showed significant effects on recorded survey effort and species diversity in most habitats.

Committee: Robert Cummins (Advisor); James Oris (Advisor); David Russell (Committee Member); Mary Henry (Committee Member); Thomas Crist (Committee Member); Jing Zhang (Committee Member) Subjects: Animals; Biology; Statistics; Wildlife Conservation; Wildlife Management; Zoology

Master of Science, The Ohio State University, 2018, Environment and Natural Resources

The ecological impacts of anthropogenic climate change are widespread, and rapid responses, such as shifting distributions, are being observed in many animal populations worldwide. The ability of a species to respond to these climate shifts is critical, and determining the adaptive capacity of vulnerable populations is important as weather patterns become increasingly variable. Migratory birds might provide a unique opportunity to study these responses since they experience climate change in different ways as they travel thousands of miles throughout their annual cycle. Thus far, many studies have focused on large-scale species-level responses, but since individual abilities to respond to changing conditions drive species-level adaptations, identifying behavioral plasticity at a finer-scale is important. If individuals can modify their space use and habitat utilization during changing environmental conditions, they might avoid consequences, such as declining food during periods of drought. Understanding if and how individuals can respond to seasonal changes in precipitation will help us make predictions about how long-term environmental change might impact populations. My goal was to better understand if and how overwintering migratory birds respond to seasonal changes in precipitation and resources by modifying their home ranges and habitat utilization. In the winter of 2016 and 2017, I sought to determine how a ground foraging Neotropical migrant of conservation concern, the Swainson's Warbler Limnothlypis swainsonii, adjusted within-season movements during dry and wet periods at Font Hill Nature Preserve in Jamaica, West Indies. I observed individuals occupying smaller home ranges in more dense habitats and modifying their home range as precipitation changed. Habitat openness had a strong effect on arthropod dry mass and denser habitats supported more arthropods on average throughout the season, although dry period prey abundance was relatively even in both mes (open full item for complete abstract)

Committee: Christopher Tonra (Advisor); William Peterman (Committee Member); Mazeika Sullivan (Committee Member); Colin Studds (Committee Member) Subjects: Ecology

Master of Science (MS), Bowling Green State University, 2014, Biological Sciences

Human land use dominates the globe, and ecologists and developers are challenged to incorporate effective conservation strategies into human-dominated landscapes that maximize biodiversity and minimize impacts to growth and production. I sought to contribute to general ecological theory by examining the effects of human-dominated landscapes on diversity and distribution patterns of midwestern breeding birds in the Oak Openings Region of northwestern Ohio from 23 May to 2 July 2013 and from 230 point count locations. To better understand the relative importance of matrix, habitat, and localized development, I modeled occurrences of 18 species of birds using an occupancy modeling framework, and occurrences of 10 of those 18 species were best explained by matrix quality over habitat loss and fragmentation. I investigated the importance of habitat structural diversity on diversity patterns of 3 guilds: Neotropical, Nearctic, and exotic species. My diversity models indicated that Neotropical diversity was best explained by habitat amount and secondarily by habitat structural diversity, while the Nearctic guild was best explained by habitat isolation and secondarily to habitat structural diversity. For a subset of survey locations distributed in the urban center, occurrences of native species were best explained by localized habitat amount and habitat structural diversity and not by the proximity to large natural reserves in the area. Finally, I used advances in distribution modeling techniques to predict the spatial distribution of Red-bellied Woodpecker (Melanerpes carolinus). My models predicted that habitat isolation and habitat amount were important determinants of occupancy for this species. My work suggests that midwestern breeding bird conservation should focus on conserving matrix quality, restoration of globally unique habitat types, and the addition of localized habitat features in the urban center.

Committee: Karen Root Dr. (Advisor); Shannon Pelini Dr. (Committee Member); Jeffrey Miner Dr. (Committee Member) Subjects: Biology; Ecology

Master of Science in Biological Sciences, Youngstown State University, 2011, Department of Biological Sciences and Chemistry

Mobbing is a common response of prey birds to aggressively displace potential predatory birds. This behavior transcends lineages and empirical evidence indicates that auditory cues from one species elicit mobbing responses in the same and/or different species. The black-capped chickadee (Pocile atricapillus) varies the number and length of D notes in the "chick-a-dee" mobbing call to denote information about the threat level a potential predator poses, with more numerous, shorter D notes designating a high threat. However, their limited natal dispersal may result in restricted transmission of culturally important vocalizations, which are known to quickly diminish in songbird populations that become isolated or are small in size, potentially exacerbating their decline. Whereas the black-capped chickadee and associated mixed flock members are common, we use this system as a model to study the cultural transmission of information important to prey survivorship and as a model of cultural breakdown in bird populations that are threatened by isolation. This project was replicated in areas containing persistent populations of Eastern screech owls (Megascops asio) and in those historically lacking them to assess whether black-capped chickadee alarm calls have a site-specific learned cultural component. Regional dialects are not hard-wired but learned in many songbirds, and locale-specific calls may uniquely convey information to members of the same mixed flock. Our data show that “chick-a-dee” warning calls differ in response to eastern screech owl presence. Where black-capped chickadees co-occurred with eastern screech owls, the average number of D notes was 5.25 but in areas lacking them, the average number of D notes was 2.25. Moreover, the length of the first D note was 40% shorter in areas with a persistent screech owl population. This indicates a breakdown in their vocal culture and suggests management that increases the connectivity of otherwise isolated populations (open full item for complete abstract)

Committee: Ian Renne PhD (Advisor); Thomas Diggins PhD (Committee Member); John Usis PhD (Committee Member) Subjects: Acoustics; Animals; Biology; Ecology