Research on island biodiversity has played an integral part in our understanding of speciation, biogeography, and adaptive radiations. The islands of the Caribbean provide an ideal location to study evolutionary hypotheses because of their proximity to species-rich mainland source areas while being sufficiently isolated to preserve an endemic biota. Most of the more than 1,000 Caribbean reptile and amphibian species occur nowhere else and are typically restricted to a single island. However, anthropogenic pressures resulting in habitat loss and degradation threaten biodiversity, leading to the loss of undescribed and unstudied species. Few studies have been conducted on the phylogenetic relationships and biogeography of Neotropical forest lizards (Diploglossidae) because of the rarity of most species. Before my work, there were 3 recognized genera and 53 species of these lizards, found in Middle America, South America, and on Caribbean islands. I gathered and analyzed sequence DNA of 3,232 genes and 642,775 aligned base pairs in 30 currently recognized diploglossid species and conducted phylogenetic, phylogenomic, biogeographic, ecological, and morphological analyses. I found that Neotropical forest lizards are older and more species-rich than previously thought. Based on this, I described 2 new subfamilies, 4 new genera, and 18 new species. I also resurrected four genera and elevated 17 subspecies to the species level. The family Diploglossidae now contains three subfamilies, 12 genera, and 91 species. I assigned all 59 Caribbean celestine species to IUCN Redlist threat classes, with the primary threats being habitat loss and introduced predators Of these, fifteen species (25%) are Critically Endangered, seventeen species (29%) are Endangered, one species (2%) is Vulnerable, and twenty-six (44%) are Least Concern. Four of the Critically Endangered species are extinct, or possibly extinct. Four of the Critically Endangered species are extinct, or possibly extinct. My biogeographic analyses indicate that forest lizards reached the Caribbean islands by at least two dispersal events, in the Oligocene and Miocene, likely by floating on flotsam from northern South America. Past and present ocean currents facilitated these initial dispersal events and subsequent dispersals among Caribbean islands. Finally, I assigned the species of Neotropical forest lizards to six different ecomorph classes based on ecology, morphology, and statistical analyses. Several of these ecomorphs appear multiple times in my phylogeny, indicating that convergent evolution has occurred within the family. / Biology

Scientists have long been interested in mechanisms that increase and decrease biodiversity on Earth and the effects they have on organisms’ interactions and functions. Global biodiversity loss is now outstripping accumulation and far exceeds expected background levels and has drawn comparisons to previous mass extinctions. The ongoing Holocene–Anthropocene extinctions differ from prior biodiversity loss, because humans have been directly implicated as major drivers of current loss—overexploitation, habitat modification and destruction, climate variability, spread of pathogens, and invasion by exotic species. Biodiversity change and especially loss can alter ecological assemblages irreversibly, which consequently can change the direction and magnitude of key ecosystem functions that organisms, including humans, rely on. Therefore, it is increasingly important to develop methods for quantifying and understanding phenomena linked to biodiversity change. In my dissertation, I develop methods to: (1) assess risk of a global-scale invasion of a pest species, (2) predict host associations for a generalist pest species, and (3) develop models to understand extinction dynamics within a clade of conservation interest. In my first chapter, I developed a framework and used it to assess a rapidly spreading regional U.S. grape pest, the spotted lanternfly planthopper (Lycorma delicatula; SLF), to spread and disrupt the global wine market. I found that SLF invasion potentials are aligned globally because important viticultural regions with suitable environments for SLF also heavily trade with invaded U.S. states. For my second chapter, I estimated host plant associations for SLF with phylogenetic imputation and predicted SLF host associations for the U.S. Many known and predicted high association host species are found in the uninvaded Midwest, Southeast, and West Coast as well as the Mid-Atlantic and Northeast, where SLF is present. Should SLF spread further, these regions are likely to experience impacts to resident trees. For my third chapter, I proposed a method for detecting three non-random extinction models and used the imperiled Caribbean lizard genus Leiocephalus as a case study to test it. Past extinctions showed directional loss of larger Leiocephalus species. However, future predicted extinctions are random for body size but show stabilizing extinction of species with either smaller or larger limb and tail lengths. Shifting extinction for Leiocephalus may occur because of changing pressures that now include anthropogenic habitat loss. Altogether, these studies attest to the value of developing and evaluating approaches to describe biodiversity dynamics in the Anthropocene. / Biology

In the southeastern United States, there is a need for a native, cool-season grass component for restoring and reclaiming grasslands and providing quality forage for livestock. Experiments were conducted on southeastern wildrye [Elymus glabriflorus (Vasey) Scribn. & C.R. Ball] to assess agronomic parameters, and establish a base of information for use in future research and breeding programs. Optimal germination requirements (temperature, light, pH, and physical dormancy) were evaluated. Our data suggests that for southeastern wildrye, the optimal temperature required for germination is between 15 and 20oC. Light treatments (constant dark, constant light, short day, and long day) did not influence germination as much as temperature, but can be a limiting factor to stand establishment. Acid source and pH treatments (HCl, H2SO4, and H3PO4 at four pHs 3, 4, 5, and 7) revealed that southeastern wildrye tends to germinate the greatest in soils with a pH greater than 5.0 (HCl at 66.7%), even though germination was observed in lower pHs. Physical dormancy treatments [bearded/glume intact (control), bearded/glumeless, debearded/glume intact, and bearded/glumeless removed] revealed the debearded/glume intact treatment had significantly less mean percentage germination (43.3%) than all other treatments. Planting depth was evaluated under five treatments ranging from surface planting to a depth of 2.54 cm. For the two years this study was conducted, the 0.64 cm treatment had greater percentage of seedlings to emerge than most other treatments. Forage quantity and quality were measured in three experiments. Orchardgrasses and tall fescue entries outperformed native entries in height, yield, and ground cover ratings. Forage quality analysis revealed statistical similarities between southeastern wildrye and improved, non-native cultivars. Harvest management evaluating cutting intervals (20, 30, 40, 60, and 80-d) and subsequent regrowth for two years was conducted. Quantity and quality analysis indicated that harvests should be conducted every 20 to 30-d in order to maintain nutritional requirements for livestock consumption. Future research should include: identification, selection, and development of southeastern wildrye plants with enhanced forage traits (persistence, palatability, lodging resistance) and establishment characteristics (higher germination, awnless), grazing trials, and fertility response trials.

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The (Re)Discovery of Mapungubwe in 1933 sparked an ongoing 89-year journey of interpretation, re-interpretation, hidden agendas, scientific racism and an evolution of worldviews. In being as deeply meaningful and entrenched in the South African psyche as it is, Mapungubwe features in a variety of representations. For this thesis, a selection of these representations were made of both those considered historical and contemporary. These were discussed and unpacked in accordance with the broader research question examining if their accuracy matters. In this unpacking archaeological theory is discussed, as well as the nationalist ideologies and racial science which was attributed to it in the early 20th Century. In addition to the selection of representations, a history of the re(discovery) and discoveries of Mapungubwe is also discussed. Ultimately, it does not matter if representations of Mapungubwe are accurate or authentic, as these facets are framework dependent, and have been found to each carry their own meaning or 'truth' around the Mapungubwe story.

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The international wildlife trade has caused significant declines in wild populations. Captive breeding can reduce the pressure on wild populations caused by overcollection, but if not properly monitored, wildlife laundering can lead to further population declines. Improving the forensic ability to detect wildlife laundering will assist in monitoring the wildlife trade and enforcing regulations, thereby aiding recovery of wild populations. Stable isotope analysis has grown in importance as a forensic tool, but improvements are needed. Here, stable isotope analysis (δ13C) on eggshells of captive bred and wild sourced island apple snails (Pomacea maculata) distinguished between the two; eggshells of captive bred snails were depleted in 13C relative to eggshells sourced from two wild populations. Thus, routine isotope sampling of eggshell material from purported captive breeding facilities can be used to identify discrepancies that would warrant further scrutiny. To address limitations of single-tissue stable isotope analysis as a forensic tool, I investigated between-tissue comparisons to differentiate between captive bred and wild sourced animals. The δ13C values of snail shell and foot muscle were significantly correlated in captive bred snails but not in wild caught snails. Between-tissue relationships therefore can detect wildlife laundering when animals are sampled in bulk. I also tested whether the use of hydroponically grown plants to reduce isotope variability in animal diets - and thereby in the tissues of the captive animals fed them - can increase the sensitivity of stable isotope analysis as a forensic tool. Kale grown hydroponically was significantly less variable in δ13C values than kale grown traditionally in soil. As predicted, P. maculata fed hydroponically grown kale had significantly less variable shell and foot δ13C values, and less variable δ15N foot values than snails fed traditionally grown kale. Combined, these experiments strengthen the viability of stable isotope analysis as a forensic tool capable of detecting signs of wildlife laundering.

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Billions of birds fatally collide with human-made structures each year. These mortalities have impacts on species of conservation concern and potentially on avian populations as a whole. This source of human-wildlife conflict also places economic and operational constraints on various human industries. Furthermore, with continued increases in urbanization, the rate and extent of collisions continues to increase. Efforts to reduce collisions have largely centered on making structures more visible to birds but have been met with limited success. Currently, there is a call for solutions to be tailored to both the environmental context of hazardous structures and to the sensory ecology of at-risk birds. In Chapter 1, we review how and why sensory ecology will help reduce in-flight collision risk for birds. A growing understanding of the sensory systems of birds and of the interface between these systems and the environment will enable the design of appropriate warning and deterrent signals. In particular, we review avian auditory and visual sensory ecology to better understand the susceptibility of birds to collisions and to recommend effective signal design. We highlight the ubiquity and salience of multi-modal signals in avian ecology and evolution, particularly as warning signals, and propose the use of multi-modal signals in mitigating collisions. We encourage the use of animal behavior frameworks to assess collision risk and collision mitigation approaches. Behavioral analyses offer numerous advantages over traditional collision measures, such as mortality estimates. Behavioral data can be generated quickly, render large sample sizes, and allow more nuanced perspectives of the context-dependence of collisions. In Chapter 2, we investigate the use of acoustic signals to reduce avian collisions with structures in open airspace. Birds have largely evolved without tall human-made structures in their flight paths and, consequently, avian perception and behavior may not be suitably primed to detect these novel hazards. Our previous work in captive settings showed that acoustic signals aid in drawing the attention of flying birds to potential collision hazards, influencing flight behavior. The current work corroborates these findings in a field setting. We projected acoustic signals into open airspace surrounding communication towers and quantified movement patterns of birds, to indicate potential collision avoidance behavior. Our results show a ~15% reduction in overall bird activity surrounding towers during sound treatment conditions, compared with control trials. Furthermore, flight movement patterns during sound treatments were characterized by significantly greater distances from and greater displacement of travel direction relative to towers, compared with control trials. Flights during sound treatments also showed significantly slower velocities, compared with control trials. Lower frequency sound stimuli (4-6 kHz) produced larger effect sizes than higher frequency stimuli (6-8 kHz). Results also co-varied with tower location and data collection date, reinforcing an appreciation of the context-dependent nature of collision risk. Our findings will inform the field of avian sensory ecology and help to assess the use of acoustic signals in collision mitigation measures.