Temperature constrains the distribution, behavior, and physiological performance of animals. As climate change intensifies, the ability of wildlife to maintain thermal balance will play a critical role in determining population persistence. Among African great apes, the West African chimpanzee (Pan troglodytes verus) inhabits a particularly broad range of habitats, but the population at Fongoli, Senegal, lives in one of the most climatically extreme regions of any chimpanzee population. This study investigates whether savanna chimpanzees face elevated physiological costs compared to those in more thermally buffered, forested habitats, and how these costs may shift under future warming. Using a mechanistic biophysical modeling approach (NicheMapR), we simulate heat and mass exchange between chimpanzees and their environments to estimate two key metrics of thermal stress: metabolic rate and evaporative water loss. We compare these values across one savanna national park, Niokolo Koba, and three forested national parks, Taï, Kibale, and Loango, under both historical and projected mid-century climatic conditions. Our findings show that savanna habitats impose consistently higher thermoregulatory costs and that future climate scenarios exacerbate these physiological burdens, particularly in marginal habitats. These results offer a novel, quantitative framework for evaluating primate vulnerability under global change and contribute to broader efforts to understand the physiological limits of species survival in warming ecosystems.

Cancer is the leading cause of death in domestic dogs and the second leading cause of death in humans. Early detection is essential for successful treatment, however the most routine tests are specific to particular types of cancer, and multi-cancer detection tests are not yet widely implemented and reliable. Cancer screening via blood biopsy and transcriptome analysis offers a possible new avenue towards pan-cancer detection. Our study seeks to understand whether there are significant correlations between patterns of differential gene expression in the white blood cells of dogs with cancer versus dogs without, and whether these signatures are conserved between dogs with blood cancer and dogs with solid tumors. Using RNA-seq data from 26 dogs with Lymphoma, 21 dogs with Solid Tumors, and 42 Controls we found multiple modules of gene expression significantly correlated with Cancer status. There was also much greater differential gene expression between Cancer and Control samples than within our Cancer groups. The biological patterns most associated with Cancer included porphyrin metabolism, cellular development, and regulation of the adaptive immune system. This study offers new insights into the effects of Cancer on the immune system beyond the tumor microenvironment and provides further evidence for the potential of the transcriptome as a tool for multi-cancer detection.

Congenital toxoplasmosis is a disease caused by initial maternal infection with toxoplasmosis that is then transmitted vertically to the fetus. The result is a myriad of health problems for the fetus caused by damage during pregnancy. Human infection typically occurs through contact with contaminated soil or water and the consumption of infected undercooked meat. Climate change, particularly rising global temperatures, influences the burden of congenital toxoplasmosis. Temperature can affect the survivability of Toxoplasma gondii, which in turn impacts the force of infection (FOI). When the parasite is rarer, the FOI could decrease, potentially leading to fewer women infected before pregnancy. This could result in more primary infections occurring during pregnancy, increasing the burden of congenital toxoplasmosis. A mathematical model was used to analyze how temperature influences the burden of congenital toxoplasmosis across different scenarios. Results showed that the burden varied with temperature, with 25°C having the greatest burden and the highest FOI. The model partially supports the hypothesis that an optimum temperature at 25°C is associated with a higher burden but does not support the prediction that a decreased FOI would increase burden. These findings demonstrate how climate change could alter the incidence of congenital toxoplasmosis requiring global health systems to adapt. Further research is needed to clarify this relationship, but these results suggest temperature plays a significant role. Public health actions should be taken to minimize the potential impacts of the disease due to a warming world.

Anthropogenic habitat fragmentation and loss have increasingly isolated populations. Under isolation, individuals are more likely to inbreed and experience depression of population dynamics. The wolves of Isle Royale, an island on Lake Superior, experienced bone deformities and nearly faced extinction due to inbreeding, while the moose of Isle Royale have shown little sign of inbreeding depression. Previous genetic studies have shown that Isle Royale moose are more inbred than their source population and have likely experienced purging of strong deleterious alleles. To investigate population structure and level of inbreeding, we conducted the first reduced-representation whole-genome sequencing of this population using RAD-seq of 99 moose. We found that Isle Royale moose show little sign of population structure and are well-mixed. This study also confirmed that Isle Royale moose diverged from their source population and have likely experienced no to very little migration. Working with previously published Minnesota moose, we also found Isle Royale moose experience less effective recombination than their source population. Lastly, we observed weak associations of homozygosity with birth year and disease status, though we surprisingly see a slight positive association with lifespan and homozygosity once excluding individuals below reproductive age. This research adds to the growing literature on how isolated, moderate-sized populations evolve and persist in the absence of gene flow.

The palmchat (Dulus dominicus) is the national bird of the Dominican Republic, yet there is a severe lack of research on this species and no published research on their vocalizations. As a group-living, cooperative species, vocal communication is necessary to mediate cooperative behaviors between group members. This project seeks to understand if vocalizations within the vocal repertoire of palmchats are quantifiably different enough to be categorized into distinctive call types using measured acoustic parameters. Furthermore, we seek to catalogue the contextual behavior associated with each vocalization within the repertoire of the palmchat to construct a database on palmchat vocal signals and lay the foundation for answering questions related to communication within and between communal and cooperative breeding palmchat groups. Field research was conducted in Punta Cana, La Altagracia, Dominican Republic for six weeks during which acoustic and behavioral data was collected. The palmchat was observed to make 5 distinct vocalizations, including one call made exclusively in the presence of aerial predators and another that indicates suspected vocal mimicry of a native predator. This research provides insight into the vocal behavior of the palmchat and opens the door to future studies on the role communication plays in palmchat societies.

Invasive Indo-Pacific lionfish (Pterois spp.) threaten Atlantic and Caribbean coral reefs, which are already stressed by climate change and overfishing. These illustrious predators reduce the abundance and biodiversity of native fish, posing significant ecological and economic risks. This study investigates whether lionfish behavior, specifically their aggregation and activity patterns, follows predictable daily rhythms that could be leveraged to optimize culling efforts. Behavioral surveys of 214 lionfish were conducted across 5 weeks in Tela Bay, Honduras. Observations were recorded across time blocks (morning, midday, and afternoon), noting activity status, microhabitat, depth, and presence of aggregations. Lionfish were more active and more likely to be found in aggregations during the afternoon (13:00–15:30). Aggregated individuals were found in shallower waters. They had significantly higher body fat percentages, particularly in pairs, suggesting either greater feeding success or energy conservation. Discovery frequency was highest in the afternoon, indicating this is the most efficient time for diver-based removals. These findings provide insights into the temporal behavior of lionfish and suggest that managers and recreational divers can improve culling efficiency by targeting afternoons. Although complete eradication is unrealistic, behavior-informed removal strategies can help reduce lionfish populations and mitigate their impacts on reef ecosystems. Future work should explore how environmental disturbances affect these behavioral trends to refine targeted management efforts.

Abstract There are no effective long-term treatments for Inflammatory Bowel Disease (IBD), more specifically Crohn’s disease and Colitis. According to the hygiene hypothesis, the incidence of autoimmune disease is higher due to the loss of exposure to helminths. In the field of helminth therapy, worms and their derived products are administered to restore the disrupted immune balance in IBD. The aim of this study is to compare Schistosoma japonicum and Schistosoma mansoni and their experimental effect on reducing inflammation in IBD using TH17 immunological outcomes and to comparatively evaluate these two worms as candidates for helminth therapy. A meta- analysis was conducted using the databases Pubmed, Web of Science, Scopus, and the software R metaDigitise to extract data in figures. The data extracted was control and experimental means, standard error, and sample size for three TH17 immunological outcomes (mRNA producing IL17, CD4+ TH17 Cells, IL17 cytokine concentration). The Hedges' g standardized mean differences and the 95 percent confidence intervals were then calculated and compared between worms. Published studies were found to show that S. japonicum is the better therapeutic worm compared to S. mansoni and that emulsified, secreted egg proteins are a likely effective treatment method. For patients who do not respond well to current IBD therapies, there is a potential future where helminth therapy could be used as an alternative treatment. If Schistosome worms were to be used in future experiments, S. japonicum and its egg proteins should be further researched and investigated.

Cuticular hydrocarbons (CHCs) serve important roles in insects as barriers against desiccation and as chemical signals within and between species. In eusocial species such as Bombus impatiens, CHCs are known to be correlated with reproductive status, behavior, and caste, but the composition of chemical profiles across different body parts and between castes remains poorly understood. This study investigates caste-specific differences in the cuticular hydrocarbon profiles of the common eastern bumble bee, Bombus impatiens, focusing on the compound classes of alkanes, alkenes, esters, ketones, aldehydes, and terpenoids. I hypothesized that queens would exhibit higher overall levels of CHCs, particularly alkanes, alkenes, and esters, and that the thorax and abdomen would show the most pronounced differences due to their association with the biosynthesis of hydrocarbons. Small colonies were established and aged under controlled conditions, after which queens and workers were dissected and separated by antennae, head, thorax, abdomen, and legs. Pentane extractions of each body part were analyzed via gas chromatography-mass spectrometry. Statistical comparisons using NMDS and ANOSIM revealed strong caste-specific differentiation across all body regions, with queens exhibiting significantly greater abundances of alkanes across all tissues and enriched levels of alkenes and esters on most body parts. The thorax displayed the greatest chemical divergence between queens and workers. The results of this experiment reinforce the idea that reproductive roles strongly shape the composition of cuticular hydrocarbons in bumble bees. Understanding these differences in chemical profiles enhances broader comprehension of eusocial organization and communication and provides further insight into potential mechanisms by which queens maintain reproductive dominance.

Disease susceptibility in bat colonies is an increasing concern, particularly following the recent global SARS-CoV-2 pandemic, and repeated spillover events. Despite extensive research, the factors influencing viral circulation within bat populations are under-investigated. This study aimed to investigate how sex, seasonality, and age structure the serological patterns of Henipavirus exposure in a captive population of Eidolon helvum bats in Ghana over a nine-year period. Longitudinal serological data were analyzed using statistical approaches including mixture models, t-tests, ANOVA, generalized additive mixed models (GAMMs), and a basic susceptible-infected-recovered (SIR) model to evaluate antibody dynamics and transmission trends. Results indicated that female bats maintained consistently higher Nipah virus antibody levels than males, particularly during the breeding season, suggesting a potential link between reproductive physiology and viral maintenance. Age-related patterns were less clear, likely due to sampling limitations. A simple SIR model captured basic serological trends but failed to fully replicate observed fluctuations, highlighting the need for more biologically complex models. These findings emphasize the importance of sex and seasonality in bat viral ecology, and contribute to improving our understanding of zoonotic transmission risk, which is critical for informing targeted surveillance and intervention strategies.

Ecologists have long been fascinated by the relationship between vegetation heterogeneity and biodiversity. Major contributors to heterogeneity include organisms that create regular vegetation patterns, such as mound-building termites, which concentrate nutrients, plant biomass, and some vertebrate distributions within ecosystems. Yet, little is known about how pattern-generating organisms affect biodiversity distributions across landscapes and in human modified ecosystems. Using a multi-scale approach, I examined the consequences of vegetated termite mounds for the distribution of birds across three ecosystems in a partially converted African savanna landscape. In Acacia-dominated savanna, saline grassland, and agricultural ecosystems of Gorongosa National Park and its buffer zone, I conducted point count surveys to estimate bird density (at the species, guild, or community level) and species richness in mound and matrix vegetation. Some bird species occurred at higher densities on mounds, while others, including some tree-dwelling species, occurred at higher densities in the matrix. In each ecosystem, avian abundance and species richness, including of functionally important guilds, were concentrated on mounds. Comparing between ecosystems, the composition of birds showed greater similarity on mounds than in the matrix. And, many savanna matrix-associated species were not detected under agricultural conversion, in areas lacking the natural heterogeneity of intact mound and matrix vegetation. Therefore, this research suggests limitations of termite mounds’ potential to maintain savanna biodiversity amidst anthropogenic pressure. The study informs a basic understanding of termite mounds as a key factor driving the distribution of African savanna bird diversity, including under agricultural conversion, at and below the landscape scale.

Rapid climate change is transforming Arctic ecosystems, including circumpolar increases in the abundance, range, and competitive dominance of tundra shrub species. Changes in nitrogen cycling caused by warming temperatures and earlier snowmelt are thought to contribute to this shrubification. However, empirical evidence quantifying how summer warming and earlier snowmelt impact the realized levels of nitrogen available to tundra plants remains limited. To fill this knowledge gap, this thesis investigates how summer warming, earlier snowmelt, and plant competition modulate nitrogen supply and shrub growth. We conducted experimental manipulations of summer warming, earlier snowmelt, and nutrient addition at two sites within and beyond the existing range of key expanding shrub species in Northern Alaska. We measured plant-available nutrients and the growth response of three focal shrub species: birch (Betula nana), willow (Salix sp.), and alder (Alnus viridis). Our results revealed that within the existing range of shrub species, warming and snow removal shifted the dominant form of inorganic nitrogen from nitrate to ammonium without changing total nitrogen supply. These changes in nitrogen availability did not translate into increased shrub growth for any species. When combined with nutrient addition treatments that elevated plant available nitrogen 50-fold, warming further increased shrub growth for birch and willow (but not alder). Beyond the current shrub range, nutrient availability showed high spatial variability and did not consistently respond to climate manipulations. Competition experiments showed that birch stem growth was significantly enhanced only when nutrient addition was coupled with competition removal. Collectively, these findings suggest that climate-driven increases in nitrogen availability are insufficient to drive Arctic shrub expansion, given the key importance of the magnitude of nutrient changes and interactive effects with other climate and biotic factors.

Plant and pollinator interactions are a form of mutualism requiring a careful balance between floral traits and pollinator behavior to maximize both pollination success and nectar consumption. This delicate relationship can result in detrimental effects on one party when the other shifts. Namely, global warming is causing phenological mismatches in many different ecosystems, where migratory species’ resources are impacted due to advanced flowering phenology. For example, many studies conducted at the Rocky Mountains Biological Laboratory (RMBL) in Gothic, Colorado have shown that the breeding season of Broad-tailed hummingbirds (Selasphorus platycercus) is shortened due to advanced blooming of early season species and no extension in late species’ blooming period. Moreover, climate change can affect environmental patterns like temperature, snowmelt timing or precipitation, which can alter resource availability for the hummingbirds within their breeding season. In this study, I analyzed the correlations between snowmelt date, daily temperature fluctuations, rainfall, floral abundance, nectar quality, and studied how these factors relate to hummingbird foraging patterns by analyzing available long-term data sets. In my results, I found little statistical evidence for a direct correlation between hummingbird visitation rate and these biotic and abiotic factors. However, I found many underlying patterns when looking at different combinations of variables. For example, temperature can increase or decrease nectar quality depending on the flower species, and the relationship between visitation rate for each species and daily temperature varies. This study reinforces the complex, interdependent way in which different abiotic and biotic factors interact to influence Broad-tailed hummingbirds’ foraging patterns, highlighting how the cascading ecological effects of climate change on the plant-pollinator mutualism.

This study investigates how aquaculture conditions influence the symbiotic community composition of reef-building corals by comparing Symbiodiniaceae clade identity between wild and aquacultured coral samples. Using ITS2 sequencing and phylogenetic analysis, DNA was extracted, purified, cloned, and sequenced from four aquacultured brain coral fragments (Favia and Platygyra spp.) and one wild Diploria labyrinthiformis sample. Results revealed that the wild coral exclusively hosted Clade B symbionts (Breviolum sp.), while aquacultured corals consistently harbored Clade C symbionts (Cladocopium sp., primarily C1 subvariants). No evidence of mixed clade infections was found. These findings suggest that environmental history may influence symbiont acquisition under aquaculture conditions, although the potential role of host identity cannot be fully excluded based on this study. From a conservation perspective, maintaining or enhancing symbiont diversity in cultured corals could improve ecological flexibility for reef restoration efforts. Future research should focus on resolving subclade variation and conducting direct comparisons within the same coral species across wild and cultured environments.

For many decades, Lewis flax (Linum lewisii), a wildflower native to western North America, has been a key study species in plant immunology, climate change, and epidemiological and ecological modeling. In the Rocky Mountain region of Colorado, it is frequently infected by its obligate fungal pathogen, flax rust (Melampsora lini), yet the direct evolutionary fitness consequences of infection are currently unknown. To strengthen the foundations for the use of flax as a predictive and translational study system of plant diseases, I investigated the effects of rust infection on key fitness measures: growth, reproduction, and survival. Over two seasons of field surveys in the Gunnison Valley, I found evidence of an association between infection and lowered likelihood of overwinter mortality, reduced fruit production, and mixed evidence regarding within-season growth. Plant size (height) was a much more robust predictor of all fitness variables than disease status, severity, or duration, especially in seedlings. These findings could also indicate distinct trade-offs between a plant’s investment in proactive immune defense and its investment in growth or overwinter survival. Building a predictive understanding of the system through an integral projection model, I help contextualize the impact of disease dynamics on future population structuring. My model showed that healthy plants do better in overall fitness, but diseased plants are reproducing faster. Further research could explore long-term fitness trade-offs over lifetimes and generations while considering how changing climates may influence future epidemics.

In Princeton, New Jersey, lives a population of Odocoileus virginianus, or Northeastern white-tailed deer, a species which is currently negatively impacting North American ecosystems due to overabundance. The expansion of invasive species is another ecological concern, so we set out to address how these two processes interact, and their impacts on the environment. We performed a survey of Princeton residents to validate that deer overabundance is a locally relevant concern. The survey revealed that residents generally held a negative opinion about deer impacts locally, both on human and natural spaces. I then used DNA metabarcoding on 169 Northeastern white-tailed deer fecal samples to characterize the composition of deer diets and how they vary seasonally. I tested the hypothesis that deer diets primarily rely on native understory vegetation, including grasses and forbs, as a result of the abundance and nutritional quality, but would switch to eating non-native trees and shrubs in the winter. We found that deer diet components vary seasonally, and this variation entails changes in group size patterns and diet quality. From elemental composition of 50 deer dung samples, we found that C:N of deer dung increased in the winter, suggesting that deer diet quality declines in the winter in accordance with seasonal changes in diet composition. Additionally, individuals in larger groups had lower quality diets, though this was not as a result of intraspecific competition. This research worked with an accessible study system to provide insight about regional environmental and social concerns, with the goal of assessing overpopulation, invasive species, and climate change on these scales.

The composition of bird communities is thought to be largely shaped by the competing pressures of environmental filtration and competition. The differential effects of these two pressures can be understood in terms of the phylogenetic and morphological relatedness of different bird communities. Bird communities in elevational gradients across the globe have been found to have decreasing phylogenetic and morphological relatedness with increasing elevation. Further, many communities are phylogenetically and morphologically overdispersed, or less closely related than expected by chance, at low elevations and underdispersed at high elevations. While it is clear that these trends exist on a local level, global studies of these relationships are currently inconclusive. This paper further explores these relationships on the continental level using eBird data to examine bird communities along nine regional elevational gradients in the Americas. In contrast to previous studies, both phylogenetic and morphological relatedness on a continental scale are found to decrease with increasing elevation. Many low elevation communities are phylogenetically or morphologically overdispersed, and some high elevation communities are phylogenetically underdispersed. These patterns hold similarly for temperate and tropical regions and largely hold across dietary guilds. These results raise further causal questions regarding the structure of bird communities along elevational gradients globally.

Investigating the geographic, systemic, and mechanistic overlaps between malaria and Systemic Lupus Erythematosus (SLE) is an interesting example of how even diseases with different causes are highly intertwined. Malaria is a disease that has existed for many centuries, imposing a selective pressure on the human genome that has induced stronger immune reactions. SLE is an autoimmune disease, with a fairly elusive etiology that similarly affects populations globally. This thesis performs a comprehensive review of existing literature and genetic studies to highlight the shared immune mechanisms that underlie these diseases despite their seemingly distinct origins. And by highlighting these overlaps we begin to elucidate the nuanced relationship between autoimmune and infectious diseases, as shaped by centuries of evolution and selective pressures. This exploration is crucial for contextualizing the immune dysregulation that characterizes autoimmune diseases as a trade-off of circumstantial, yet historic, adaptations. By recognizing this trade-off, we can view immunity less as an isolated system, and more as a product of history, thereby explaining its imperfectness. It encourages readers and researchers alike to constantly question simplistic assumptions of immunity as being either entirely protective or defective and calls for a greater integration of evolutionary and even ecological principles in healthcare and disease management.

In 2024, four hydroelectric dams were removed from the Klamath River in Southern Oregon and Northern California. Their removal will allow Chinook Salmon access to historic migratory routes that have been blocked by these dams for over a century. This paper aims to synthesize the history and events that led to this dam project, as well as the current and future implications of dam removal, focusing on identifying Indigenous and Western perspectives surrounding these issues. The fight for water rights and challenges with federal and state governments led to decades of activism from Indigenous communities to restore the depleted salmon populations. With this removal, tribal nations in the Klamath River Basin will regain access to a significant traditional food source, while also preserving cultural heritage and spiritual connections to a sacred species. Chinook Salmon and other salmonids are critical for these Indigenous communities' mental, physical, and spiritual health. Environmentally, dam removal will increase water quality, lower water temperatures, and reduce sediment load, which are all crucial factors in increasing Chinook salmon population sizes, as well as increasing juvenile and smolt survival. Restoration efforts for the surrounding habitat include improving river flow and restoring riverbank vegetation. Future management will require continued collaboration between tribal and governmental agencies, and the continued success of Chinook Salmon recovery is dependent on ongoing monitoring and conservation efforts.

The following study investigated temporary declines in air pollution observed during the COVID-19 lockdown and potential changes in adult asthma prevalence across four urban U.S. East Coast cities: Boston, Massachusetts; Baltimore, Maryland; New York City, New York; and Washington, D.C. Leveraging the COVID-19 lockdown as a natural experiment, this research combined annual air pollutant data from the U.S. Environmental Protection Agency (EPA) with asthma prevalence data from the Center of Disease Control’s Behavioral Risk Factor Surveillance System from the years 2013 to 2023 and conducted multiple statistical analyses to determine associations between air pollutants and asthma prevalence. Regression and mediation models were utilized to assess the effects of nitrogen dioxide (NO2) and fine particulate matter (PM2.5) on asthma prevalence. Results showed that NO2 concentrations significantly declined during the COVID-19 period and were modestly associated with reduced asthma prevalence. Mediation analysis suggested that NO2 partially mediated the relationship between the COVID-19 period and observed decreases in asthma prevalence. PM2.5 did not demonstrate a significant mediating effect. Although asthma prevalence declined during the COVID-19 lockdown period, the decrease was not statistically significant. Additionally, the rebound in asthma prevalence after COVID-19 may reflect diagnostic delays or other non-environmental factors impacting the data. Nonetheless, these findings reinforce and inform previous research regarding the impact of air pollution on respiratory health outcomes and asthma prevalence. Furthermore, the results of this study support tactics to reduce NO2 emissions as a strategy to improve public health in urban environments.

Timber harvesting in eucalyptus plantations poses a significant disturbance to koala populations, yet little is known about how individuals respond behaviorally throughout the harvest process. This study examines the home range size, movement velocity, and dispersal patterns of koalas before, during, and after harvest in Tasmanian blue gum plantations (Eucalyptus globulus) on Kangaroo Island, South Australia, and compares them to a control population on the mainland of South Australia in Belair National Park. Using GPS telemetry data from 51 individuals, considerable variability was found in spatial behavior on plantation land compared to the control in native vegetation in Belair, as well as in post-harvest behavioral responses, shaped by age class and sex. While some koalas remained within their original ranges, others dispersed further, occasionally crossing property boundaries. These results underscore the importance of landscape-scale planning and the retention of movement corridors to support wildlife in production forests. These findings provide insight into koala resilience and habitat use following disturbance, with implications for future plantation management and conservation of arboreal mammals in modified environments.