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Grassland birds have narrow habitat requirements that are influenced by food availability, habitat composition, and habitat structure. Because survival is influenced by habitat quality and availability, understanding habitat requirements is critical for conservation. I determined how Henslow’s Sparrows (Centronyx henslowii) use grassland habitat in the breeding season. In the past 10 years, technology advancements have allowed researchers to study the habitat use and movement ecology of understudied birds, such as grassland birds. I deployed nanotags on 47 adult Henslow’s Sparrows at two sites in southern Ohio to determine home range size and habitat use in relation to distance to edge and shrub, as well as the post-breeding dispersal and migratory timing.I predicted that Henslow’s Sparrows would use core grassland habitat and avoid edge and shrubs. I found no difference in 95 % home range size between female (0.10 ± 0.03 ha) and male (0.32 ± 0.18 ha) Henslow’s Sparrows. Henslow’s Sparrows used shrubs when available and edge habitat as refugia after disturbance. I also found that Henslow’s Sparrows use fields into August, past dates typically recommended for disturbance (e.g., mid to late July), which suggests the need to leave corridors and patches for refugia after management such as mowing or burning. I determined the fall migratory departure timing of 13 Henslow’s Sparrows. I found that Henslow’s Sparrows are at risk for entanglement which resulted in mortality of two birds. A third bird found entangled was found alive, entangled in vegetation, and was released after I removed the nanotag. I also found that 24 Henslow’s Sparrows were able to remove nanotags and several damaged their nanotags. While I do not recommend the use of nanotags on this species in future studies, my study did result in determining fall migratory departure timing of Henslow’s Sparrows in Ohio which was previously unknown.

Pollinators are globally important for maintaining the health of our agricultural systems and facilitating plant reproduction, and understanding how they respond to the dual threats of climate change and habitat destruction is essential for our ability to conserve their populations. We have a basic understanding of how pollinators respond to habitat loss and increasing temperatures, but we know less about how habitat management can be used to mitigate their response to the detrimental effects of climate change. Managing a natural community for biodiversity can provide thermal resources in the form of patches of sun and shade or potential thermal refugia for ectothermic pollinators to utilize as they experience thermal stress from climate change.Here, I aim to understand how bees and other floral visitors utilize thermal and foraging resources over a range of varying canopy cover. I measured floral visitation rates to black-eyed Susan plants placed in sunlit and shaded patches at 15 different sites at Kitty Todd Nature Preserve in Swanton, OH. I recorded both different environmental and surface temperatures to investigate drivers of bee body temperature, which I also measured.We found significantly more bees visited plants placed in sunlit than in shaded patches (X2 = 12.361, df = 1, pboot = 0.005). With higher floral surface temperatures and higher light intensities, we recorded higher levels of bee visitation. Bee body temperature was best related to abaxial (underside) leaf surface temperature among all the thermal metrics that we measured, with higher body temperatures at higher abaxial temperatures.My results show the importance of maintaining open areas within a matrix of wooded habitat for bees and other pollinators, although shady patches may become more important in other contexts. Light intensity may be one of the more important factors driving both surface temperature variation and preference by bees for sunny areas over shaded ones. These results, as well as those relating to bee body temperature, indicate that efforts to conserve bee populations should be informed by thermal resources in addition to more frequently researched floral and nesting resources.

Conflict with wildlife continues to escalate as human population increases and development expands. Understanding how vertebrates interact with the environment is a critical component to conservation ecology. Movement patterns reflect spatial and temporal changes associated with resource availability, life history stages, and habitat use. This study explored how vertebrate mortality could be used to understand the critical factors impacting the consequences of permeability, i.e., ability to move between patches on the landscape, in a mixed disturbance landscape. We assessed how spatial and temporal heterogeneity influenced terrestrial vertebrate mortality. In the biodiversity hotspot of the Oak Openings Region (OOR) of northwest Ohio, we surveyed repeatedly, across three years, approximately 50 kilometers of road segments. Vertebrate mortality locations (N=654) were related to road (e.g., traffic, road width), structural (e.g., canopy cover, soil average water capacity), compositional (e.g., landcover) and productivity (e.g., NDVI) measurements. We found vertebrate mortality locations were positively related to traffic, road width, canopy cover, and normalized difference vegetation index (NDVI) but negatively related to landcover as it becomes more altered (i.e., natural to agricultural). Our consistent findings across years suggest that the spatial components were influencing mortality differences more than temporal differences, and intra-year differences do not impact mortality in a way that would steer long term mitigation of permeability issues. We developed spatially explicit models for predicting current vertebrate mortality probabilities across the entire OOR. Proportion of residential/mixed landcover area was the most influential variables of mortality occurrence probability. We found mortality was well predicted and the results of the same key variables were robust across taxa and years. The models developed can serve as an assessment tool for evaluating conservation and management to improve landscape permeability. Our research demonstrates the validity of employing road surveys as a reliable method for gaining insights into locations of roadway vertebrate mortalities and the spatial factors influencing the corresponding lack of permeability. Our methodology is not limited to the OOR; it can be applied anywhere with sufficient mortality and environmental data to address ecological questions of interest. It is an accessible approach to address a wide variety of conservation challenges.

Ixodes scapularis, otherwise known as the blacklegged tick, has rapidly expanded across eastern North America in the last 50 years due to changing climate, land use change, and associated shifts in host distribution across the landscape. Blacklegged ticks are major vectors of disease agents, including those that cause Lyme disease, the most common vector-borne disease in the United States, leading to public health concerns in the USA and Canada. Species distribution models (SDMs) can help assess blacklegged tick occurrence and abundance, avoiding extensive time or funding that would otherwise be needed for active surveillance. Additionally, SDMs can reveal important ecological drivers of expansion and highlight areas where blacklegged ticks are likely to spread. To understand the ecological drivers of blacklegged tick occurrence and abundance, we reviewed all published blacklegged tick SDMs as of December 2022, and identified common traits of SDMs and areas for improvement. Next, we studied the spatial distribution and abundance of blacklegged ticks in Ohio, a midwestern state in the USA where the northeastern and upper midwestern ranges of the blacklegged tick are converging over the Ohio River Valley. To develop comprehensive models, we considered climate, landscape, and host covariates in a spatially explicit framework. Additionally, we considered several spatial scales for landscape covariates to identify possible cross-scale linkages between blacklegged ticks and their hosts. With these considerations, we developed the first predictive occurrence and abundance models for blacklegged ticks in Ohio, USA, identifying key drivers of blacklegged tick abundance and areas of high disease risk.

Terrestrial carnivores are some of the most imperiled species today due to their large home range requirements, high metabolic demands, sensitivity to habitat fragmentation, and persecution by humans. Carnivores play a vital role in shaping community dynamics through top-down regulation, and changes in their abundance, distribution, or intraguild interactions can alter such top-down influences. As such, the recovery of carnivores as a conservation tool to restore ecosystem functions (termed: trophic rewilding) has become increasingly popular. Additionally, many carnivores readily expand their range or reestablish in human-dominated landscapes and coexist with humans. Therefore, carnivore conservation, management, and the use of terrestrial carnivore species for trophic rewilding efforts require not only an understanding of their ecological interactions within the carnivore guild, but also the broader context of these interactions, including the effects of human activities on and predator-prey and competitive interactions.My doctoral research addresses these questions using community and species- level approaches with carnivores in two human-dominated systems: one that harbors the full complement of carnivore species and did not experience species extirpation (brown bear, wolf, lynx, wildcat, red fox, badgers– Romanian Carpathians, RO), and one depauperate, dominated by native and non-native mesocarnivores and witnessing a dynamic recovery of native species (e.g., coyote, bobcat, red fox, gray fox, black bear,raccoon–Ohio, OH). Specifically, in the Romanian system, I used camera trap data coupled with community ecology models to 1) understand seasonal drivers of spatial patterns of apex and mesocarnivore species occurrence and 2) determine the relative importance of top-down versus bottom-up processes in shaping community dynamics of carnivores and prey. In the Ohio system, I used multiple data sources paired with population-level models to 3) evaluate the viability of recovering bobcats and the population susceptibility to various sources of mortality and 4) determined regional density of bobcats to further inform population trajectories and statewide management.First, I used two seasons of camera trap data with multispecies occupancy models and found seasonal differences in the environmental predictors of species-level occupancy for lynx, wildcat, and wolf in the Romanian Carpathians. I also found differences in predictors of co-occurrence between seasons for both lynx-wolf and wildcat-wolf co-occurrence. For both seasons, conditional occupancy probabilities of all three species were higher when another species was present. These results indicate that while there are seasonal differences in predictors of occupancy and co-occurrence of the three species, co-occurrence in our study area is high. Second, I used apex predator, mesocarnivore, and ungulate camera trap data with piecewise structural equation modeling and found that neither top-down nor bottom-up processes alone best describe the predator-prey dynamics in the Romanian Carpathians. Instead, I found that environmental variables in combination with both top-down and bottom-up processes best explained the community dynamics. Therefore, when considering trophic rewilding and conservation efforts it is important to protect viable habitats and prey populations before predator reintroduction.Third, I used road mortality and habitat suitability data with data from theliterature on bobcat demographics in a spatial population simulation framework to assess the viability of the recovering Ohio bobcat population under various management scenarios. I found that the Ohio bobcat population can withstand marginal increases in mortality, but responses to changes in mortality varied greatly with changes in density and marginally when targeting different age classes. These findings will be used to inform current and future management decisions for the Ohio bobcat population. Lastly, to further fine-tune findings from the spatial population simulation model, I estimated the regional density for bobcats in two area of Ohio using eDNA from scat and spatially explicit capture-recapture models. I found that there is regional variation in bobcat density, and bobcat density in southeast Ohio was high when compared with other recovering US Midwest populations, but similar to other eastern populations.Cumulatively, these findings advance our understanding of terrestrial carnivore populations in human-dominated systems and their role in shaping overall community dynamics. The research in Romania highlights the need to protect habitat for both predators and prey and provides a way forward to implement conservation strategies, such as trophic rewilding, that are based on community ecology. Similarly, the research in Ohio highlights the role of the environment and human-induced mortality in population dynamics, while also addressing critical information gaps to inform carnivore management in a recovering carnivore species, the bobcat.

The Painted turtle (Chrysemys picta) is a widespread North American species, and its subspecies found in Ohio is the Midland Painted turtle (Chrysemys picta marginata). While it is generally a widespread species and less at risk than other freshwater turtle species, understanding different local populations of the species can help us better understand the species as a whole, as well as factors that may play a role in conserving other freshwater turtle species. I conducted a mark-recapture study over the course of two separate study periods to assess the Midland Painted population in Conrad Balliet Family Nature Preserve’s Pond, a local pond in Clark County, Ohio. Of the turtles recorded, 28 individual turtles were captured, and there was a 1.33:1 ratio of male turtles to female turtles and a 0.19:1 ratio of juveniles to adult turtles. Males tended to be in higher abundance in traps when there were few females and accounted for more recaptures than females. The estimated population size for the pond is 30 Midland Painted turtles. Males were smaller in size than females, in carapace length and width, plastron length and width, shell height, and weight. This information, and further studies on the pond’s population, can serve to inform conservation methods for this species and other applicable freshwater turtle species as is relevant.