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 …

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, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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. …

Migration And Winter Movement Ecology Of Red-Throated Loons (Gavia Stellata) In Eastern North America, Carrie E. Gray

Electronic Theses and Dissertations

Migratory animals exploit multiple habitats across the extent of their range and conditions experienced can have considerable effects on individual survival and population size. Understanding where species are exposed to survival risks and evolutionary selection pressures and how connected are different portions of the range requires defining a complete annual movement network with all major seasonal sites—e.g., breeding, migratory stopovers, staging, and wintering—and describing where populations may or may not overlap in space and time. I used movement data collected from satellite-tagged Red-throated Loons (Gavia stellata) to provide new and more accurate information about spatial use during the full annual …