Master of Science, The Ohio State University, 2022, Environment and Natural Resources

In North America, the replacement of greenspaces with human-made structures causes hundreds of millions, if not billions, of avian fatalities every year. Through the continuous increase in urbanization, threats to avian wildlife are exacerbated by a multitude of related factors such as habitat loss, fragmentation, and pollution. Bird collisions with buildings are an integral component of these threats because they directly cause avian mortality, and they are expected to increase as human populations continue to grow in urban areas. Bird collisions with buildings represent the largest source of collision mortalities, ahead of collisions with windmills, power lines, and vehicles. Cities serve as physical impediments for numerous bird species, as many urbanized landscapes are located along migratory routes. Birds play an important role in the proper functioning of ecosystems, and they also play an important role within human societies. Therefore, it is important to explore determinants of bird collisions with buildings to identify effective mitigation strategies that aim to counter the rapid decline of bird populations. Previous studies have identified that numerous factors correlate with bird collisions with buildings. These factors include species' life-history traits, artificial lighting at night, building characteristics, and atmospheric conditions. There are likely a multitude of other factors influencing bird collisions with buildings at any point in time, and this further increases the complexities behind collision dynamics. I evaluated previously identified factors related to bird collisions with buildings to test their influence on bird collisions in Cleveland, Cuyahoga County, Ohio, during fall of 2017. I identified that life-history strategies related to migration distance and foraging height, along with family groupings, differentiated collision frequencies. For example, long-distance migrant and warbler (Family Paru (open full item for complete abstract)

Committee: Stephen Matthews (Advisor); Andrew Jones (Committee Member); Alia Dietsch (Committee Member); Robert Gates (Committee Member) Subjects: Biology; Conservation; Ecology; Environmental Science; Wildlife Conservation; Wildlife Management

Master of Science, University of Toledo, 2020, Biology (Ecology)

Many Neotropical migratory songbirds are experiencing significant population declines (Wilcove and Terborgh 1984, Robbins et al. 1989, Rosenberg et al. 2019), the majority of which remain critically under-studied, impeding informed, science-based conservation and management. To effectively implement conservation and management strategies, it is critical to understand population dynamics and demography, which are most informative when all stages of a species' life cycle are incorporated (Sillett and Holmes 2002, Anders and Marshall 2005, Streby and Andersen 2011, Peterson et al. 2016, Kramer et al. 2018). In migratory passerines, this means considering the full annual cycle, including periods that may be difficult to study (e.g., migration, the non-breeding season, and the post-fledging period; Sillett and Holmes 2002, Webster et al. 2002, Anders and Marshall 2005, Streby and Andersen 2011, Cox et al. 2014, Marra et al. 2015, Peterson et al. 2016, Kramer et al. 2018). Knowledge of annual cycle ecology is especially limited for female songbirds, desert-dwelling songbirds, and other western USA Nearctic-Neotropical migrants (McKinnon and Love 2018, Bennett et al. 2019, Hedley 2019), which have experienced community wide declines in the past century (Iknayan and Beissinger 2018). The Gray Vireo (Vireo vicinior) is a small (~11-14 g), under-studied migratory songbird that breeds primarily in pinon (Pinus spp.)-juniper (Juniperus spp.) savannas and structurally similar arid landscapes in the southwestern United States and northwestern Mexico (Barlow et al. 1999; but see Hargrove and Unitt 2017 for chaparral habitat associations of the likely-disjunct California population). Gray Vireos are currently listed as threatened in New Mexico (NMDGF 2018), as a species of Conservation Concern by US Fish and Wildlife Service (USFWS 2008), and as a Watch List Species by Partners in Flight (Rosenberg et al. 2016). These listings are likely due to a lack of demographical informatio (open full item for complete abstract)

Committee: Henry Streby (Committee Chair); Kathy Granillo (Committee Member); Brian Carpenter (Committee Member); Jeanine Refsnider-Streby (Committee Member); Eric Zeigler (Committee Member) Subjects: Animals; Biology; Conservation; Demography; Ecology; Fine Arts; Gender; Gender Studies; Organismal Biology; Wildlife Conservation; Wildlife Management; Zoology

Master of Science, The Ohio State University, 2020, Environment and Natural Resources

Urbanization can have profound influences shaping patterns of songbird diversity. For many species, urbanization poses considerable challenges, yet in many instances urban areas provide important habitat for songbirds, most notably riparian urban areas. With renewed interest to maintain functioning urban forests, understanding the interactions between songbirds and their urban environments is critical to making informed land management decisions. My research addresses habitat usage of breeding urban songbirds in Columbus, Ohio, focusing on the relationship between urban songbird presence and behavior and the vegetation in urban riparian forests. Previous songbird studies have been conducted in the Columbus metropolitan area since 2001 and have focused primarily on the impacts of urbanization on abundance, nesting, and survival. My goals for this study were to add to this knowledge base by examining potential correlations between songbird territory density and structural vegetative characteristics in urban forests and to investigate the foraging strategies of urban songbirds. The first component of my study examines the relationship between the breeding territory densities of individual songbird species and the vegetation structure of urban sites. Given that vegetation structure has been linked to urban songbird abundance and survival, the number of trees, the size of trees, and the density of exotic or native stems in a site may influence the territory density of certain species. I tested the hypotheses that overall songbird territory density will be greater in areas will fewer exotic stems and Neotropical territory density will increase with structural diversity. I conducted spot maps in urban riparian forests in Columbus, Ohio from late April to August in 2019 and compared these data to spot maps conducted by my colleagues in 2007 and 2011 to determine territory densities for the most common species, which included the Blue-gray Gnatcatcher, Blue Jay, Carolina (open full item for complete abstract)

Committee: Stephen Matthews PhD (Advisor); G. Matthew Davies PhD (Committee Member); Charles Flower PhD (Committee Member); Christopher Tonra PhD (Committee Member) Subjects: Urban Forestry; Wildlife Conservation; Wildlife Management

PHD, Kent State University, 2018, College of Arts and Sciences / Department of Biological Sciences

In zebra finches, estradiol contributes to sexual differentiation of the song system and influences dimorphisms in auditory processing, but the receptor(s) underlying its action are not entirely known. Whereas mRNA and/or protein for nuclear estrogen receptors ERa and ERß are minimally expressed, the G-protein coupled estrogen receptor 1 (GPER1) has a much greater distribution within song nuclei, the vocal organ (syrinx), and a major auditory region in the brain. This has only been verified at a few ages (post-hatching (P) day 21 and adults) so in general, little is known about GPER1 expression and importance particularly during early development. To expand knowledge of this receptor, in this dissertation, I semi-quantitatively described GPER1 protein at a wider range of ages (from P15 – P45) in the major song nuclei and specific auditory regions in male and female zebra finches. Within song nuclei, GPER1 was localized to the High Vocal Center (HVC), robust nucleus of arcopallium (RA), and lateral magnocellular nucleus of the anterior nidopallium (LMAN), whereas Area X (only present in males) was devoid of GPER1 receptors. In auditory regions, GPER1 was detected within Field L, caudomedial nidopallium (NCM) and nucleus interfacialis (NIf). Overall, expression in these regions appeared to vary with age and sex, with some patterns that were consistent with a role for GPER1 in shaping sex differences in structure and function. To more directly examine the functional significance of this receptor specifically within the song system, the GPER1 antagonist, G-15, was intracranially administered to zebra finches for 25 days beginning on the day of hatching. In males, G-15 significantly decreased nuclear volumes of HVC and Area X. It also decreased muscle fiber sizes of ventralis and dorsalis in the syrinx. In females, G-15 had no effect on measures within the brain, but did increase fiber sizes of both muscle groups. Finally, to address the importance of the method of drug (open full item for complete abstract)

Committee: Sean Veney Ph.D. (Advisor) Subjects: Biology; Developmental Biology; Endocrinology; Neurobiology; Neurosciences; Physiology

Master of Science, The Ohio State University, 2017, Environment and Natural Resources

Each spring and fall, hundreds of species of North American birds migrate between breeding and wintering grounds. Many migrant songbirds are in steep decline, and understanding the movement behavior and habitat use of these birds during migration is crucial to developing effective conservation action. One of the most rapidly declining songbirds in North America is the Rusty Blackbird, which has declined more than 85% over the last 50 years. Very little is known about their behavior and habitat requirements during migration, so we studied the species during spring and fall migration at a high-traffic stopover (refueling) site in northern Ohio. We utilized an automated telemetry array in the western Lake Erie basin and across Ontario to track landscape-scale movements of radio-tagged birds during and after migratory stopover events. We found that stopover duration of Rusty Blackbirds was unusually long for a songbird (25 days), and that nearly all captured birds (98%) were molting body feathers in the spring, which may partly explain the long stopover. Many individuals also made landscape-scale (10-35km) movements during their stopover event. These behaviors describe a migration strategy that closely resembles shorebird migration, where birds congregate to forage for several weeks at key staging areas. This indicates that high-quality staging habitat may be critically important to Rusty Blackbird populations. In addition to movement behavior, we investigated their fine-scale habitat preferences on stopover. We found that Rusty Blackbirds selected microhabitat with shallow water and leaf litter, often avoiding dense herbaceous cover. They also preferred areas close to habitat edges with some canopy cover, and with a mixture of habitat types. Our description of Rusty Blackbird stopover habitat use and behavior will help inform conservation and management practices across the species' migratory range.

Committee: Christopher Tonra PhD (Advisor) Subjects: Wildlife Conservation

Doctor of Philosophy, The Ohio State University, 2012, Environment and Natural Resources

Behavioral responses to predators during the breeding season can critically affect the nest success of songbirds. However, the ability of birds to modify behavior based upon perceived and actual predation risk at multiple spatial scales (e.g. local (within-site), site, and landscape) and in novel (e.g., urban) environments remains poorly understood. In this dissertation, I explored how information about predation risk influenced the nest-site selection and nestling provisioning behavior of two species of songbirds – northern cardinals (Cardinalis cardinalis) and Acadian flycatchers (Empidonax virescens), which are two relatively common forest songbirds of eastern North America with contrasting responses to urbanization. I studied the use of information regarding predation risk and behavioral responses of birds during the 2006-2010 breeding seasons at riparian forest sites within the urbanizing landscapes of central Ohio. Specifically, I investigated the following questions: 1) how do cardinals and flycatchers choose nest locations based on information about local-scale nest predator activity patterns, 2) do cardinals and flycatchers incorporate private (i.e. detectable information only known to the individual) and public (i.e. detectable information known to all individuals) information about predation risk in nest-site selection, and 3) are provisioning rates to nestlings adjusted relative to public information about site-level predation risk? The ways that birds used information about predation risk varied with species, type of behavior, and the scale of information. Cardinals incorporated local scale information about predator activity, previous nest fate, and at times, actual predation risk at the site scale, to modify nest-site selection. They demonstrated sensitivity to information at multiple scales and an apparent ability to adjust nesting behaviors in ways that may allow them to thrive in urban areas. On the other hand, flycatchers used only local-scale pre (open full item for complete abstract)

Committee: Amanda Rodewald PhD (Advisor); Stanley Gehrt PhD (Committee Member); Charles Goebel PhD (Committee Member); Mazeika Sullivan PhD (Committee Member) Subjects: Ecology

PHD, Kent State University, 2012, College of Arts and Sciences / School of Biomedical Sciences

Neural dimorphisms in the songbird represent one of the most extreme examples of sex differences observed in vertebrates. Interestingly however, despite their identification more than four decades ago, information on the exact mechanisms related to how they arise is very limited. In this dissertation, I provide evidence supporting a potential role of the membrane bound G-protein coupled estrogen receptor GPR30, in estrogen-mediated dimorphic brain development of the zebra finch. In particular, this receptor may directly regulate sex differences within song nucleus HVC. Since brain dimorphisms are not completely dependent on sex steroids, the second part of my dissertation identified possible gene candidates that may also be involved. More specifically, I present evidence for a potential role of the Z-linked ribosomal gene rpS6 in the development and maintenance of dimorphic features in song nuclei HVC and RA where it is enhanced in males than in females. I sum up this dissertation by providing evidence that the function of rpS6 is likely modulated by estrogens, as evidenced by its up-regulation in the presence of estradiol. Taken together, my work provides a model for how genetic and hormonal factors may function to affect neural dimorphisms in the zebra finch.

Committee: Sean Veney Dr (Committee Chair); Gail Fraizer Dr (Committee Member); Heather Caldwell Dr (Committee Member); Eric Mintz Dr (Committee Member); Chun-Che Tsai Dr (Committee Member) Subjects: Neurology