<p>  </p> <p>Plant chemistry influences plant-nutritional quality, which in turn impacts plant-insect interactions. Plant secondary metabolites are pervasive in the plant kingdom and have been shown to influence both plant nutritional quality and plant-insect interactions. Levels of these secondary metabolites, as well as quantity, can impact availability of key macromolecules herbivorous insects need for optimal nutrient intake. Herbivorous insects can modulate their growth, rate of consumption, and frass production in response to diet with poor nutritional quality. Insects can also increase the production or activity of nutritional and detoxification enzymes to offset diet with poor nutritional quality. While the influence of plant secondary metabolites on nutrient intake is better understood in many plant systems, it is not well understood in plant-insect interactions involving <em>Cannabis sativa</em>. An increase in large-scale agricultural production of <em>Cannabis</em> has introduced a novel secondary metabolite, cannabinoids, a terpenophenolic compound with known physiological effects in many animal systems, onto the landscape. While insects have been shown to exhibit reduced performance on higher cannabinoid diets, insects lack human-analog cannabinoid receptors, so how these compounds interact with insect herbivores is not well understood. A goal of this study was to increase the understanding of how cannabinoids influence herbivorous insect performance. </p> <p>To understand the influence of cannabinoids on insect performance and enzyme activity I performed no-choice feeding bioassays on fall armyworm (<em>Spodoptera frugiperda</em>) with artificial diet spiked with different concentrations of cannabidiol (CBD). I measured growth, consumption, and frass production. From these same larvae, I also analyzed detoxification and nutritional enzyme activities. I found that as CBD concentration increased in diet, growth and consumption of fall armyworm decreased. I also found that as CBD concentrations increased, protease and cytochrome P450 enzyme activity decreased, and β-glucosidase enzyme activity increased. These outcomes highlight potential mechanisms for both behavioral and biochemical mechanism by which CBD confers resistance to insect herbivores.</p> <p>As agricultural production of <em>Cannabis</em> continues to increase, cannabinoids will continue to alter the chemical landscape of agricultural systems. How insect herbivores contend with cannabinoids is an important step in understanding plant-insect interactions in <em>Cannabis </em>systems. Identification of the structural and functional characteristics of protease and cytochrome P450 enzymes influenced by cannabinoids are possible future avenues of research that can better develop our understanding of <em>Cannabis</em>-insect interactions.</p>

<p>As human activity expands across the globe, disturbance of wildlife by anthropogenic activities such as fragmentation of habitat, and wildlife-human conflicts escalate. The Pueblo of Santa Ana is receiving pressure from road expansion and urban development and is concerned with the impacts of those activities upon wildlife populations. Specifically, mule deer is a species of concern for their Department of Natural Resources (DNR). Mule deer are important economically, culturally, and for recreational purposes. The DNR understands the need for better understanding mule deer ecology to manage for potential conflicts in their interactions with expanding human infrastructure. My objectives were first to model mule deer habitat use in and around the Pueblo of Santa Ana during the summer and winter at different times of the day. My second objective was to understand the relative impacts of different scenarios for road development in the Pueblo of Santa Ana upon the disturbance of mule deer using an Individual Based Modeling (IBM) framework.</p> <p> Using Geospatial Positioning System telemetry collar data collected on mule deer I used proximity based habitat predictors in a general linear mixed model to create resource selection functions. Generally I found that the season had a greater impact on mule deer habitat use than the time of day. Female and male mule deer select for similar habitat but sexually segregate in their summer distributions. My findings are consistent with results from other locations where mule deer studies have been conducted. In chapter two, I used the Simulation of Disturbance Activities (SODA) modeling framework to investigate the impact of vehicles on mule deer disturbance response behaviors, alert and fleeing. Using this framework I compared a baseline scenario to road expansion scenarios (DamRoad, ByPass, DeerCrossing) estimating the frequency of disturbance behavior of mule deer for each such scenario. My results show that mule deer were disturbed most in the baseline model. There were no significant differences in the frequency of disturbance for female mule deer across scenarios. Male mule deer did have some significant differences in alert and fleeing behavior across scenarios. My results may be a function of assumptions made in my modeling. Specifically, I assumed that mule deer would shift their areas of activity to new portions of the Pueblo of Santa Ana in response to altered habitat quality caused by new roads. If mule deer did not shift their areas of activity accordingly, my models may provide inaccurate assessments of disturbance patterns. </p> In conclusion my findings are similar to results from other locations. Specifically, the inferences that roads and road development are important to consider for mule deer management transcends variation associated with the unique characteristics of the Pueblo of Santa Ana mule deer population. Finally, my results suggest that the use of an IBM modeling framework has the potential to provide insights into the disturbance of mule deer by vehicular traffic even if my conclusions were constrained by study design.

The conversion of natural habitat to urban areas has lasting impacts on wildlife and biodiversity. Known effects to urban wildlife include direct mortality while crossing roads, reduced species diversity, and habitat fragmentation and degradation. Among wildlife occupying urban areas, turtle populations can be particularly impacted in anthropogenic landscapes. Snapping Turtle (<i>Chelydra serpentina</i>) is one of the most common species found within urban wetlands, but populations are beginning to show declines in northern portions of their geographic range. The preservation and management of this species is aided by knowledge related to its spatial ecology. I investigated <i>C. serpentina</i> home range, movement, habitat use, and habitat selection in a midwestern USA urban wetland complex during two active seasons (May-August 2019 and 2020) using radiotelemetry. Home range sizes and movement did not differ between sex or sample year except the mean movement of males decreased from 2019 to 2020. No differences in mean monthly movement were found between sexes but mean monthly movement did differ between month and year. Habitat use was skewed during the active season and did not differ between sex or year, but there were positive habitat associations between forested wetlands and modal centers of activity (MCA). Habitat selection was tested at two spatial scales by comparing random points to home ranges and turtle locations using Euclidean Distance Analysis. Turtles appeared to select home ranges from available habitat site-wide but did not select habitat within home ranges. Home range selection included semi-permanent open water, trail, road/barrier, permanent open water, scrub-shrub, ditches, shoreline, and vegetated ponds, while upland forest, field and agriculture habitat were avoided. Home ranges appear to be constrained by available habitat and movement differences between years may be due to anthropogenic change in water levels. The use of space seems to be more affected by wetland size and connectivity than proximity to barriers, which suggests that management practices that protect turtles from accessing roads and railways will benefit populations. Additionally, habitat selection and association indicate that ditches are utilized as corridors between wetland areas. When feasible, increasing the connectivity of large wetlands containing many habitat types should have positive impacts on the persistence of populations in human dominated landscapes.

<div>Animal species that consume carrion provide an essential ecosystem service by recycling the resource’s nutrients intothe ecosystem. Carrion is an unpredictable and ephemeral resource that is variable across a landscape and is an important resource to many taxa. Furthermore, the colonization of small vertebrate carcasses by different species influences competition and coexistence dynamics, which in turn influence species dominance. The American burying beetle, <i>Nicrophorus americanus</i>(ABB) has recently experienced a dramatic decline in abundance and geographic range. An essential requirement of the ABBs life cycle is the availability of small vertebrate carcasses for reproduction. We know little about the preferred carrion base necessary to support a healthy ABB population. However, we know that reproduction is costly in buying beetles, and physiological trade-offs associated with resource use likely influences metabolic activity, fecundity, and survivorship. Furthermore, successful monitoring of wildlife populations requires reliable estimates of abundance, dispersal, and population demographics. This is often problematic within ABB populations because they are elusive, nocturnal, often occur at low population densities, and are a species of conservation concern. These factors constitute a management and conservation challenge in ecology and conservation biology. Therefore, identifying and evaluating the resources used for reproduction, along with life history trade-offs associated with resource use, in addition to species abundance within a habitat are key requirements for this species’ conservation and management. We used stable isotope analysis of carbon and nitrogen to determine the carrion base used by burying beetles in situ. Additionally, we evaluated resting metabolic rate and the energetics of prehatching parental care using flow through respirometry. Finally, we investigated the utility of using photographs with an individual identification machine learning software program paired with program MARK to estimate population abundances of burying beetles.<br></div><div><br></div><div>Between populations, ABBs are not specializing on either avian or mammalian carrion but are using both natural and provisioned carrion for reproduction. Furthermore, among co-occurring burying beetle species, we observed large niche overlap in both populations. Periods of sexual development and prehatching parental care were periods of elevated metabolic activity, which provides insight into life-history tradeoffs associated with resource quality. Carcass size did not significantly influence the metabolic rate of parents, however, the number of days needed to 13prepare a small carcass was significantly shorter compared to large carcass preservation. Furthermore, beetle pairs on larger carcasses accumulated significantly larger metabolic cost over the course of parental care. Additionally, using digital images of naturally occurring spot patterns on beetles’ elytra, we tested the feasibility and the application of photographic mark-recapture (PMR) using machine learning software. We demonstrated the utility of using PMR in estimating population abundance for Nicrophorusspp. based on elytral spot patterns. Future research is needed to fully quantify reproductive resource use over time, and how it influences ABB abundance in extant and reintroduced populations. For successful management and reintroduction of ABBs, managers must consider the resources used for reproduction, the composition and availability of appropriately sized potential reproductive carrion, they should limit intra-/interspecific competition for carrion resources and need accurate data on species abundance.<br></div><div><br></div><div><br></div>

<p>Infectious  diseases  are  becoming  increasingly  common  and  problematic  for  wildlife populations in many parts of the world. Disease prevalence and severity fluctuate over time, often due to the ubiquitous pressure of seasonality, or  the cyclic changes in ecological systems. However, for  many  host-pathogen  systems,  our  understanding of important  seasonal  drivers of  disease remains fragmented. For example, when seasonality of a disease is studied in medium and high latitudes, winter is often neglected, despite this being a period of physiological and immunological challenges associated with extreme environmental conditions. Therefore, my aim is to examine  drivers  of winter Infection dynamics of the amphibian fungal pathogen <em>Batrachochytrium dendrobatidis</em>. First, <em>B. dendrobatidis </em>infection prevalence was measured from spring through fall to understand local infection levels and anthropogenic influences (Chapter 1). Next, laboratory  experiments examined the effects of <em>B. dendrobatidis </em>on critical thermal minimum of two anuran species to identify how this pathogen influences the ability of hosts to survive winter (Chapter 2). Another laboratory experiment tested how road de-icing salt (commonly used in winter) influences <em>B. dendrobatids </em>and a tadpole host condition and subsequent host-pathogen interactions (Chapter 3). Finally, a field-based exploration of <em>B. dendrobatidis </em>infection dynamics was conducted during winter to understand how infections vary during in this season and between two overwintering strategies (Chapter  4). Winter  infection  dynamics  in  many  host-pathogen  systems are largely understudied, but the knowledge gained by this work can demonstrate how harsh environmental conditions of winter that can exacerbate otherwise benign infections, and affect the ability of hosts to sustain infections during winter. This work can therefore inform predictions and investigations of  infection  dynamics in  subsequent  seasons to  better  understand  the  seasonality  of  wildlife diseases.</p>

<p>Disturbance regimes like freezing and thawing (FT) can have potentially significant impacts on nutrient release from soil and are predicted to increase with climate change. This is particularly important in biogeochemical hotspots like floodplains that can both remove and release nutrients to surface waters during flooding. Connection between the river and floodplain can improve water quality by reducing nutrient loads through microbial processes and sedimentation. However, conditions during flooding can also lead to phosphorus (P) release from pools that are not normally bioavailable. Disturbance events like FT can also lead to changes in bioavailable P due to microbial cell lysis. This study investigates differences in P chemistry and flux during flooding from intact soil cores that have undergone a FT cycle compared to soils that have not undergone freezing. Floodplain soils were collected from four sites along the Wabash and Tippecanoe Rivers in Indiana. We hypothesized that (i) the primary pools of P within the soil would change with freezing (ii) and flooding; (iii) frozen treatment cores would release more P during flood incubations than unfrozen control cores; and (iv) processes controlling P release during flood incubations would change after FT due to changes in the primary pools of P in the soil cores. </p> <p> </p> <p>On average, soil cores that underwent FT released greater amounts of P than unfrozen cores over the course of the 3-week experimental flood incubation. Phosphorus release in both unfrozen control and FT treatment cores during flooding was explained in part by soil extractable Al and Fe and redox status; however, P release was influenced by soil Ca-P in the FT cores to a greater extent than unfrozen cores. Phosphorus release in FT cores occurred faster than in control cores with overlying water concentrations peaking 2 weeks after onset of flooding, followed by lower concentrations at 3 weeks. Whereas control cores had some release and uptake early on but then released P throughout the 3-week incubation—supporting the hypothesis that drivers of P release were different after FT. Interactive effects of FT and flooding suggest that concentration gradients between soil pore water and overlying surface water could have enhanced dissolution of the Ca-P pool, highlighting the importance of floodwater chemistry to P dynamics following FT. This study provides an important link between observed winter floodplain P loss and potential drivers of release and retention, which is critical to informing floodplain restoration design and management through all seasons.</p>

The population genetics of species occupying formerly glaciated regions are not only impacted by glacial retreat but also agricultural land use that is typical of such regions. Areas which have experienced glaciation often display a lowered amount of genetic variability and minimal population structure, and these effects become more predominant with increasing distance from a potential refugial population. Meanwhile, agricultural land use over the recent past has also been demonstrated to disrupt population structure distribution through disturbance regimes. The purpose of this study was to assess potential post-glacial and agricultural effects on populations of creek chub (Semotilus atromaculatus) in two agricultural watersheds that differ in the glacial history. The Saint Joseph River (SJR) watershed, Indiana and Michigan, USA was entirely glaciated during the last glacial maxima, while the Little Miami River (LMR) watershed in Ohio, USA, is situated on the boundary of the glacier. The degree of agricultural land use also varies between and within the two watersheds. Using eight microsatellite loci, 312 individuals were genotyped from 13 sites in SJR and 2,318 individuals from 29 sites in LMR. Measures of genetic differentiation showed that there was strong differentiation between watersheds. Analyses within watersheds recovered additional but weaker differentiation that was mostly associated with the geography of sub-watersheds and isolation by distance. Proximity to the glacial boundary appeared to play a minimal role in genetic differentiation and genetic variation. Differentiation among localities was not directly associated with the glacial boundary within LMR, and localities in this watershed had lower allelic richness and heterozygosity than those in the fully glaciated SJR. After accounting for the positive correlation of stream distance in LMR using partial Mantel test, both glacial history and agricultural land use were positively correlated with genetic differentiation. However, these predictor variables were also strongly correlated with one another which prevented disentangling the two potential effects. Within SJR, no 10 relationship of genetic differentiation with agricultural land use was recovered. My study shows that there is not a simple relationship between glacial history, contemporary land use, and genetic differentiation in creek chub. Rather, it appears that the patterns of genetic variation observed may be more closely linked to the dispersal behavior of creek chub within and among watersheds, and the history of effective population size within watersheds.

<div>Sea turtles are integral components of many marine ecosystems. Green turtles (Chelonia mydas) are generally herbivorous, feed primarily on seagrasses, and are endangered in the Caribbean. The species utilizes extensive marine habitats for foraging and migratory routes, and because of its broad distribution, it is difficult to conduct population assessments. Here, I assessed commonly used techniques for monitoring green turtles in the wild. Specifically: (1) biopsy sampling for molecular assays and (2) unoccupied aerial vehicles (UAVs) deployment and boat-based surveys for population monitoring.</div><div><br></div><div>Skin biopsies are collected from sea turtles for a variety of molecular analyses; however, very little information exists on the natural healing rates at the site of the biopsy in the wild. In Chapter 2, I monitored the healing rates of 17 juvenile green turtles in Eleuthera, The Bahamas, for up to 488 d after taking a 6mm biopsy tissue sample. Complete tissue repair and maturation was observed after a year and a half, and there was no evidence of infection at any point during the healing process. While scarring persisted for several months, biopsy sampling had minimal long-term impact.</div><div><br></div><div>UAVs are increasingly being used to monitor marine megafauna. In Chapter 3, I evaluated the efficacy of using UAVs to detect sea turtles when compared to boat-based surveys. During UAV surveys, the UAV was flown along preprogrammed routes in four creek systems. A boat survey was conducted simultaneously on the same path. I used regression analyses for each survey type to assess the effects of environmental variables on turtle detection rates My results indicate that there were no statistically significant difference between the numbers of turtle detected via boat or UAV surveys; however, there were clear differences in the time and potential cost associated with either method.</div>

<p>  </p> <p>Semi-aquatic mammals, such as American beavers (<em>Castor canadensis</em>), muskrats (<em>Ondatra zibethicus</em>), North American river otters (<em>Lontra canadensis</em>), and American mink (<em>Neogale</em> <em>vison</em>), often play important roles in their ecosystem. Beavers and muskrats can manipulate plant community structure through the use of woody debris and forbs. As mesocarnivores, North American river otters and American mink can also drive community structure through the predation. Traditionally, these species are monitored using sign surveys (i.e., walking transects and visually identifying scat, tracks, and latrines). Camera trapping has also been used to survey semi-aquatic species occupancy to a lesser extent. However, due to their almost exclusive use of edge habitat, they may be ideal species to camera trap. Another more recently employed survey method is environmental DNA (eDNA), which involves the extraction of DNA from environmental samples (such as soil, water, air, and snow) to determine species occupancy. In this study, I evaluate environmental DNA and camera trapping as survey methods for detecting semi-aquatic mammals around northeastern Indiana. In the first chapter, I used eDNA sampling and camera trapping to monitor seven sites for three weeks during March – May 2021 in order to determine the presence of American mink. I found that the naïve occupancy for each site was 0.86. Although the detection probability of eDNA was lower than that of camera trapping (0.25 and 0.36, respectively), the occupancy models created suggest that there was no difference in detection probability between the two methods. I also compared the cost and time spent per sample and found that both were 20% lower for eDNA than camera trapping. The results of my study suggest eDNA may be a cost- and time-effective method for surveying for American mink occupancy. The objective of my second chapter was to determine the number of camera traps required to obtain reliable data for detecting semi-aquatic mammals. A minimum requirement for number of camera traps would be useful knowledge for wildlife managers in terms of budgeting and resource management and could also help to refine current camera trapping methodologies. I camera trapped four ponds for four weeks during June – July 2021, varying the number of camera traps (1 – 5) used at each pond each week. I collected a total of 66,543 photos and detected one semi-aquatic mammal throughout the study period (<em>Neogale vison</em>). Due to the lack of semi-aquatic mammals detected, I could not perform any analyses.</p>

<p>Despite being distributed worldwide and easily collected, the biology, ecology, and taxonomy of Ptiliidae Heer, 1843, or featherwing beetles, have not been well studied. In a study from 2007 to 2009, Ptiliidae were extracted from various polypore fungi collected throughout Costa Rica in an effort to expand biogeographic knowledge of Ptiliidae. Fungi and Ptiliidae were identified to genera and collection sites mapped. Beetle genera are able to inhabit different polypore genera and were found at a higher rate of co-occurrence than reported in previous studies. We identified <i>Cylindrosella costariciensis </i><b>sp. n.</b>, with the potential of two more new species to be described.</p>