Life Sciences Commons^™

Retroviral Infection Dynamics In Maine's Wild Turkeys, Stephanie A. Shea

Electronic Theses and Dissertations

Widespread wild turkey reintroductions in the late 1900s have led to increases in population density and geographic distribution across North America. This rapid population expansion has put them into proximity with closely-related wild and domestic avian species, increasing the risks of pathogen transmission. Lymphoproliferative disease virus (LPDV) is an avian oncogenic retrovirus detected in wild turkeys in 2009, and previously known to infect domestic turkeys. Following its initial detection, surveys reported variable LPDV prevalence across eastern North America with most wild turkeys being asymptomatic, however diagnostic cases revealed 10% mortality of LPDV-infected individuals. Given its recent detection, little is known …

Biotic Interactions At Species’ Range Limits In A Changing Climate, Isaac Shepard

Electronic Theses and Dissertations

As the global climate changes, many species are shifting their geographic ranges, often towards the poles or upslope in elevation. The ubiquity of these observation has renewed discussions about the mechanisms that determine species’ range margins. Leading hypotheses state abiotic variables should be the most important factor for setting range limits in environmentally stressful habitats. However, I propose an alternative hypothesis that biotic interactions may still be critically important for setting range limits, even in abiotically stressful habitats. Using a model system of ponds in the Rocky Mountains of Colorado, I developed several field experiments to empirically test the role …

Natural Regeneration Dynamics And Survival Influenced By Abiotic And Biotic Factors In A Bottomland Hardwood Forest, Lydia J. Voth Rurup

Electronic Theses and Dissertations

Riparian ecosystems are vital to the landscape, providing critical services including water filtration and purification, flood and erosion control, carbon sequestration, biodiversity support, and aesthetic value. Bottomland hardwood forests, however, are threatened by invasive species, land loss/conversion, inconsistent or absence of harvesting disturbances, and altered hydrological patterns, leading to reduced success of desired, native species. This research assessed regeneration dynamics and one-year survival in a seasonally-flooded bottomland hardwood forest at Boggy Slough Conservation Area in East Texas to identify abiotic and biotic factors important for successful establishment of native regeneration. Areas sampled included two that were previously treated with herbicide …

Whole Genome Sequencing Reveals Genes And Pathways Associated With Anthrax Survivorship In Plains Zebra, Carly Dickson

Electronic Theses and Dissertations

Pathogens are significant selective forces on natural populations, and therefore genes and gene regulators involved with combatting infections experience some of the strongest selection pressures in the vertebrate genome. Studies in humans have used high-throughput next generation sequencing to identify genes associated with infectious diseases, however, these studies have been limited in wildlife systems despite their potential to improve public health, agricultural production, and wildlife conservation. Anthrax is a globally distributed disease caused by the virulent bacterial pathogen Bacillus anthracis, which has significant effects on morbidity and mortality in humans, livestock, and wildlife populations. In this study, we utilize whole …

Cumulative Effects Of Habitat Change: American Marten Habitat Selection And 30 Years Of Forest Harvesting In Maine, Tyler Woollard

Electronic Theses and Dissertations

Wildlife habitat conservation in landscapes where human activities cause chronic habitat disturbance is contingent upon developing land management strategies that minimize the effects of future habitat changes on wildlife populations. Long term studies can provide unique opportunities to understand how species respond to progressive habitat change, and such an understanding can reveal ways in which the often conflicting objectives of wildlife habitat conservation and human land use can be reconciled. Characterizing how animals respond behaviorally to habitat conditions may be a useful tool for identifying potential negative effects of disturbance before such effects impact rates of species occurrence, population demography, …

Forest Disturbance And Occupancy Patterns Of Carnivores: Results Of A Large-Scale Field Study In Maine, Usa, Bryn E. Evans

Electronic Theses and Dissertations

Understanding trends in the abundance and distribution of carnivores is important at global, regional and local scales due to their ecological role, their aesthetic and economic value, and the numerous threats to their populations. Carnivores in Maine range from the American black bear (Ursus americanus), to numerous native mesocarnivore species, such as American marten (Martes americana), fisher (Pekania pennanti), coyote (Canis latrans), red fox (Vulpes vulpes), bobcat (Lynx rufus), Canada lynx (Lynx canadensis) and to two small weasel species (Mustela erminea and Neogale frenata). …

American Woodcock (Scolopax Minor) Migration Ecology In Eastern North America, Alexander Fish

Electronic Theses and Dissertations

Across temperate regions of North America, migrating animals must contend with seasonally influenced thermal extremes, changing food abundance, and stochastic weather events. Migrating individuals must locate suitable areas, termed stopover locations, to rest and rebuild energy reserves needed to continue migration (Rodewald and Brittingham 2004, Taylor et al. 2011). The American Woodcock (Scolopax minor; woodcock hereinafter) is a migratory forest bird that has experienced long-term population declines (Seamans and Rau 2019). We created the Eastern Woodcock Migration Research Cooperative, including 34 provincial, federal, state, and non-governmental partners, with the goal of describing the migration ecology of woodcock in the eastern …

Experimental Warming Effects On Growth, Yield, And Biotic Pressure Of Wild Blueberries In Maine, Yu-Ying Chen

Electronic Theses and Dissertations

As the global temperature rises, a need exists for understanding the potential impacts of warming on the wild blueberry industry in Maine. Warming can change the physiology, growth, and pest pressure of crops, and also accelerates the evapotranspiration rate, resulting in decreased soil moisture. The objectives of this study were: (1) To characterize the response of phenological, morphological, and physiological traits of the wild blueberries to warming; (2) To quantify the impacts of different temperature levels on yield and berry quality; (3) To determine the abiotic and biotic factors that may influence yield, such as winter damages, freezing temperatures, the …

Lipidomic Analysis Of Various Developmental Stages Of Physcomitrium Patens, Deepshila Gautam

Electronic Theses and Dissertations

Lipids maintain fluidity of the cell membrane during the lifetime of all organisms. The moss Physcomitrium patens, an early land plant, enters reproductive phase under cold (15°C) conditions relative to its gametophytes (22°C). Thus, we hypothesized that their lipid content and composition would be distinct. Using ESI-MS/MS, we showed that the content and acyl composition of 11 lipid classes varied during development. Galactolipids were abundant in gametophytes but insignificant in sporophytes; among phospholipids, phosphatidylcholine was predominant in both phases. Although, sporophytes contained around five-fold less lipids than the gametophyte, their phosphatidic acid content, which accumulates during stress, was 18-fold …

Distinguishing Mustela From Neogale (Mustelidae) Through Both A Qualitative And Quantitative Analysis Of Skull And Tooth Morphology, Ronald W. Peery

Electronic Theses and Dissertations

Weasels and mink (Mustela and Neogale) can be difficult to distinguish osteologically due to similarities in morphology, thus suggesting the need for an accurate tool in distinguishing among taxa. This study utilized a combination of character state and stepwise discriminant function (DFA) analyses to examine potential distinguishing features of skull and tooth morphology. Measurements and ratios were collected from all 18 extant musteline species, as well as the extinct Neovison macrodon, Mustela rexroadensis, Mustela meltoni, Mustela gazini, and Mustela jacksoni. Unidentified musteline specimens from the Gray Fossil Site were also included. Results of …

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …

Eastern Wild Turkey Population Ecology Across Land Use Gradients In Maine, Matthew Gonnerman

Electronic Theses and Dissertations

Wild turkeys are a wide-ranging species with considerable cultural and economic significance. As they can exist across a variety of ecosystems, understanding how land use affects population vital rates can be a crucial component of informed population management. This is even more important for turkey populations in Maine, where harsh winters can have negative impacts on survival and reproduction.

I used a combination of banding and tracking data to better understand the relationship between turkey population ecology at their northern range limit and the diverse landscape gradient they occupy in Maine. I produced wildlife management district specific estimates of turkey …

Bioacoustic Studies Of Population Size And Microdialects In An Island-Living Savannah Sparrow Population, Abby Lynn Jill Hensel

Electronic Theses and Dissertations

Bioacoustic monitoring provides an innovative technique for studying the behaviour and ecology of wild birds. In this thesis I use bioacoustic monitoring as a tool for studying Savannah Sparrows (Passerculus sandwichensis). In my first data chapter, I tested the accuracy of passive acoustic monitoring in estimating population size and annual survival in an island population of Savannah Sparrows. Six years of data reveal that passive acoustic monitoring with autonomous recorders provides accurate underestimates of population size and annual survival. I found that passive acoustic monitoring estimated population size with 74% accuracy, with higher accuracy in low density years. I also …

Examining The Combined Impacts Of Rapid Senescence And A Low Water Stressor On Maternal State, Egg Quality, And Fitness In Chinook Salmon, Madison A. Sturba

Electronic Theses and Dissertations

Assessing the impact of environmental challenges on maternal state and breeding success is important for predicting how migratory Pacific salmon populations will respond to an increasingly stressful world. The overall goal of my thesis was to examine fine-scale senescent changes in female Chinook salmon over time, whether these changes impacted ovulation and egg quality, and whether exposure to an environmental challenge (low water) during senescence subsequently provoked even stronger state-dependent responses to ultimately impact female longevity and egg survival. Following an experimental decrease in water availability, I quantified changes in physical, physiological, and reproductive maternal state, then linked these changes …

Physiological State Determinants Of Maternal Cortisol Signaling And Its Impact On Offspring Quality And Fitness, Sydney Currier

Electronic Theses and Dissertations

Assessing the intergenerational effects of maternal stress is important for predicting how offspring will respond to changing environments. The overall aim of my thesis was to quantify the effects of maternal state on maternally derived egg cortisol and determine whether this variation in egg cortisol impacts Chinook salmon offspring performance and fitness in a sex-specific way. I quantified within-female changes in maternal energetics and reproductive metrics that I linked to egg quality and ultimately embryo survival. I found egg cortisol increases with increasing maternal plasma cortisol, and increases further as plasma cortisol levels rise with each day that eggs are …

Parasites And Sexual Selection In A Sexually Dichromatic Toad, Nicole Erin Shangi

Electronic Theses and Dissertations

Parasitism is among the most common and successful life history strategies on Earth, leading to constant coevolution between parasites and hosts. Parasites continuously pressure hosts to evolve more effective parasite resistance, fueling interest in the relationships between expression of sexually selected host ornamentation and parasite resistance. By studying parasite-mediated sexual selection we gain unique insights into the evolution of animal traits. In this thesis, I attempt to further our understanding of a sexually dichromatic neotropical anuran by studying its parasites in the context of sexual selection. Firstly, in the General Introduction (Chapter 1), I reviewed important background information key to …

Lower Trophic Relations Within The Lake Ontario Invertebrate Community As Assessed By Chemical Tracers, Donald Robert Uzarski

Electronic Theses and Dissertations

The lower trophic food web of Lake Ontario plays an important role in the lake’s ecosystem, yet the trophic relationships of these taxa are not well understood. Utilizing carbon (δ13C) and nitrogen (δ15N) stable isotopes as a tool to trace the flow of energy through the system, the main objective of this thesis was to understand the isotopic variability and trophic relationships of invertebrate taxa through space and season in Lake Ontario. Using an extensive dataset collected in 2012 and 2013, this study was conducted in two research chapters. The first chapter assessed variation in the isotopic signature of three …

Does It Take A Community To Save A Species? Examining The Use Of Community Interactions To Restore Unionid Species At Risk, Roland Adriaan Eveleens

Electronic Theses and Dissertations

The conservation and restoration of freshwater ecosystems are complex. Knowledge from community ecology, conservation biology, and restoration ecology was integrated to interrogate the role of species interactions involving freshwater mussels (order Unionida) as keystone species. Freshwater mussels require host fish and provide ecosystem functions for other species throughout aquatic and riparian ecosystems, yet conservation efforts remain focused on focal mussel species or host fish associations. My thesis explored species co-occurrences within mussel and benthic macroinvertebrate community assemblages, and systematically reviewed the published literature to assess the breadth and reported effectiveness of mussel restoration. Community analyses confirmed species co-occurrences across environmental …

The Function And Evolution Of Wood-Warbler Flight Calls (Parulidae), Zach G. Gayk

Electronic Theses and Dissertations

Animals produce vocalizations to communicate with territorial rivals, to communicate with potential mates, to alert others of predators, or to stay in contact with other animals. To date, little research has focused on the vocalizations that animals use to communicate during migration. Many birds produce flight calls, which are short calls given by migratory birds on the wing. The function of flight calls is poorly understood but they are thought to help migrants maintain contact with other individuals during movements between breeding grounds and wintering grounds. Across four data chapters in my dissertation, I investigated the function and evolution of …

A Social-Ecological Examination Of Moose In Maine: Habitat, Management, And Changing Seasonality, Asha Dimatteo-Lepape

Electronic Theses and Dissertations

Maine is a New England state with rich ecosystems and diverse opportunities for enjoying the outdoors. Maine is well known as a popular nature-based tourist destination, and is often associated with its notable moose population. Social-ecological systems in Maine are highly intertwined, and as such, are especially susceptible to impacts resulting from climate change. Moose health in the state is already being negatively impacted by climate change with high infestation rates of winter tick resulting in declining moose health and high moose calf mortality. Given that late winter is a time of high stress and increased mortality of moose due …

Energetic Impacts Of Passage Delays In Migrating Adult Atlantic Salmon, Sarah R. Rubenstein

Electronic Theses and Dissertations

For any migratory organism, habitat connectivity is critical for population stability. Structures that impede movement between necessary habitats can be damaging to population persistence. In riverine systems, dams act as migratory barriers, altering ecosystems and delaying, injuring, or otherwise impairing migratory fish movement into essential habitat. Critically endangered Atlantic salmon (Salmo salar) populations in Maine have been on the decline since the 1800s. Because most Atlantic salmon rivers are now highly dammed systems, hydropower dams have been cited as causal to the decline in returning adult populations. Previous studies have demonstrated that Atlantic salmon experience substantial delays below dams while …

Acting Out Of Lyme: Characterizing The Human Dimensions Of Lyme Disease Interventions, Katherine C. Perry

Electronic Theses and Dissertations

Lyme disease (LD), a tick-borne disease caused by the bacterium spirochete Borrelia burgdorferi, is the most commonly occurring tick-borne illness in the United States with the majority of cases concentrated in the Northeast. In Maine, as well as the rest of North America, LD is transmitted to humans via infected black-legged ticks (Ixodes scapularis). As the life cycle of the black-legged tick is tightly coupled with forest ecosystems, prevalence of the disease is common in endemic forest landscapes, and individuals spending time in these areas face an increased risk of exposure to LD as well as other tick-borne diseases. While …

Vertical Habitat Gradients: Comparing Phytoplankton Dynamics In Lakes With Low To Moderate Dissolved Organic Carbon Concentration, Matthew J. Farragher

Electronic Theses and Dissertations

Concentrations of dissolved organic carbon (DOC) increased across lakes of Maine for several decades before stabilizing or decreasing in recent years. To investigate the seasonal effects of DOC on phytoplankton habitat structure, I assessed vertical gradients of temperature, oxygen, light, and chlorophyll in four lakes in Acadia National Park from under ice through fall turnover in 2020. Lake DOC concentrations ranged from low (~2 mg L-1) to moderate (~4 mg L-1). Low-DOC lakes were clearer, with greater mean Secchi depths (9-15 m) than moderate-DOC lakes (5-6 m). Moderate-DOC lakes experienced hypolimnetic anoxia in the summer and had more variable concentrations …

Environmental Dna Monitoring Of Non-Native Mudpuppy (Necturus Maculosus) And Transient Rainbow Smelt (Osmerus Mordax), Vaughn Holmes

Electronic Theses and Dissertations

Whether considering an expanding non-native species or a priority native species with a dwindling local population, the monitoring of low-abundance, sporadically distributed, or otherwise elusive populations, can prove difficult. In separate studies, we tested the viability of environmental DNA (eDNA) for monitoring a species in both of the above circumstances, the common mudpuppy (Necturus maculosus), a spreading non-native species, and rainbow smelt (Osmerus mordax), a declining species of concern. Mudpuppy are fully aquatic salamanders that were introduced to the Belgrade region of central Maine in 1939 and again in 1940. Though they had been present for nearly 80 years when …

Risk Perceptions Of Tick-Borne Diseases In Maine: Surveying Outdoor Enthusiasts, Sarah Rappaport

Electronic Theses and Dissertations

Tick-borne diseases (TBDs) are a growing concern throughout the United States. Maine’s reliance on nature-based tourism as an industry and its proximity to the epicenter of Lyme disease in the northeast makes the state vulnerable to the negative consequences related to further spread of TBDs. Acadia National Park and the state’s recreational areas should be a focus of tick-disease-related research because of the influx of visitors to natural areas during the summer and fall -- the seasons that correlate with the majority of tick-borne infections. In 2019 alone Acadia National Park received nearly 3.5 million visitors, making the park one …

Using Predator Vocalizations To Deter Raccoon Predation On Nests Of Diamondback Terrapins (Malaclemys Terrapin), Colleen Elizabeth Naeger

Electronic Theses and Dissertations

No abstract provided.

Community Structure And Dynamics Of Benthic Macroinvertebrates In A Recreated Headwater Stream System On A Valley Fill In A Retrofitted Watershed Located In The Appalachian Coalfields Of Southeastern Kentucky (U.S.A.), Steven W. Bailey

Electronic Theses and Dissertations

The extraction of coal from steep-gradient surface mining sites such as in the Appalachian Coalfields of the U.S. produces excess debris that is often placed in adjacent valleys resulting in the creation of valley fills. Not only are headwater streams buried in the process, but watershed functions are either destroyed outright, or become fragmented and disconnected from adjacent ecosystems resulting in adverse effects to downstream biological communities. In this dissertation, the dynamics of stream macroinvertebrate community structure, composition, diversity, and biotic integrity are assessed at a “proof of concept” stream system recreated on a retrofitted valley fill. For comparison, two …

The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang

Electronic Theses and Dissertations

The Gulf of Maine northern shrimp (Pandalus borealis) once supported a significant winter fishery for the Gulf of Maine (GOM). Although the shrimp fishery is not comparable to the lobster business, it provided fishermen and many coastal communities jobs and incomes in winters after lobster seasons. However, a moratorium has been put on the shrimp fishery since 2014 due to record low population abundance and perceived recruitment failures. The recruitment failures have been correlated with warming water temperatures over the past decade. The GOM has been recognized as experiencing rapid warming as a result of global climate change. …

The Impacts Of Embryonic Arsenic Exposure Of Fundulus Heteroclitus, Torey Bowser

Electronic Theses and Dissertations

Arsenic is a toxic metalloid that exceeds safe drinking water standards in groundwater in many locations worldwide. Arsenic exposure in fish has been linked to destruction of gill tissues, impairment of growth, decreased muscle mass, memory impairment, increased aggression, and avoidance behaviors. We examined the behavior of mummichogs (Fundulus heteroclitus) following arsenic exposure during development in two studies. Embryos were collected from fish from three reference sites: Scorton Creek (SC), Massachusetts, Wells Harbor (WE), Maine, and Block Island (BLOC), Rhode Island and two contaminated sites: Callahan Mine (CM), Brooksville, Maine, and New Bedford Harbor (NBH), Massachusetts. Embryos were …

Examining The Links Between Environmental Variation, Foraging Behaviour And Foraging Success In An Arctic Seabird, Alyssa Eby

Electronic Theses and Dissertations

Arctic regions are experiencing increasing variability in inter-annual sea ice dynamics ultimately impacting marine Arctic ecosystems. Arctic-breeding seabirds, such as thick-billed murres (Uria lomvia) are thus likely to be negatively impacted by fluctuating environmental conditions through its influence on prey availability. Additional extrinsic factors (colony size and chick demand) and intrinsic factors (sex) are also likely to impact foraging behaviour and success of murres in combination with environmental conditions. First, we tested the effect of colony size on colony sensitivity to environmental change at two low Arctic colonies of varying sizes, Coats Island, Nunavut and Digges Island, Nunavut …