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Full-Text Articles in Life Sciences

Pushing It To The Limit: Determining Asian Elephant (Elephas Maximus) Olfactory Sensitivity And Discrimination Through A Behavioral Choice Task, Matthew S. Rudolph Dec 2021

Pushing It To The Limit: Determining Asian Elephant (Elephas Maximus) Olfactory Sensitivity And Discrimination Through A Behavioral Choice Task, Matthew S. Rudolph

Theses and Dissertations

Elephants have shown remarkable olfactory capabilities. Their sense of smell impacts their foraging choices, behavior, and ultimately, survival. Being able to detect a target odor can allow elephants to locate specific resources, identify threats, and find receptive conspecifics. Previous studies have shown that elephants can consistently detect target odors, but have not identified the limits of this detection. Thus, to investigate the extent of elephants’ odor detection capabilities, we tested Asian elephants in a two-step odor discrimination task. First, we investigated whether elephants could detect odors at varying levels of dilution after a training procedure, and then whether they could …


Small Mammal Community Ecology And Ectoparasite Dynamics In A Tamaulipan Thornscrub Habitat, Brandi Giles Dec 2021

Small Mammal Community Ecology And Ectoparasite Dynamics In A Tamaulipan Thornscrub Habitat, Brandi Giles

Theses and Dissertations

Small mammals play many roles in ecosystems and are known as great indicators of overall ecosystem function and health, but they are also highly competent hosts for ticks and tick-borne disease. In this study, I gathered data on small mammal community ecology and species diversity, abundance, and overall ectoparasite (i.e., ticks) dynamics in a south Texas Tamaulipan thornscrub habitat. I also assessed differences in these parameters in edge versus interior habitats across a gradient of habitat fragmentation and species assemblage. Lastly, I assessed which host and environmental factors can be utilized for predicting parasitization of small mammals in this habitat. …


Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee Dec 2021

Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee

Theses and Dissertations

Bioavailable phosphorus loads exported to Lake Michigan from the Milwaukee and Sheboygan River Watersheds appear to have increased in the last 40 years despite meeting total phosphorus (TP) loading goals set by the Great Lakes Water Quality Agreement (GLWQA).Overall, bioavailability of P delivered from the Milwaukee and Sheboygan Rivers was highest during the warmer months, which coincides with the nearshore nuisance algae growth season. However, first order loss rates of SRP calculated during baseflow recession were also greatest during the summer, suggesting that increased river residence time during the summer could reduce export of bioavailable P. Observations of phosphorus partitioning …


Assessing The Trophic Positions Of Lake Michigan Fishes Using Stable Carbon And Nitrogen Isotopes, Benjamin Alan Turschak Aug 2021

Assessing The Trophic Positions Of Lake Michigan Fishes Using Stable Carbon And Nitrogen Isotopes, Benjamin Alan Turschak

Theses and Dissertations

Lake Michigan is the second largest Laurentian Great Lake and is characterized by broad spatiotemporal variation in ecosystem processes such as nutrient cycling and energy flow. Variation in ecosystem processes—such as those induced by invasive dreissenid mussels—and subsequent changes in the spatiotemporal distribution of resources (i.e. prey or habitat) has resulted in major changes in Lake Michigan’s fish community. The ability of fish species to cope with spatiotemporal resource dynamics is at least partially dependent on their ability to shift apparent trophic position along various resource gradients. The objectives of this research were to quantify trophic positions of Lake Michigan …


Some (Im)Material Girls, Living In (Im)Material Worlds, With Seeds, Stars, And Shit, Matthew Weiderspon May 2021

Some (Im)Material Girls, Living In (Im)Material Worlds, With Seeds, Stars, And Shit, Matthew Weiderspon

Theses and Dissertations

This writing situates material and gestural vocabularies cultivated in my artwork in relation to my lived experience; primarily my rural upbringing in Colorado. Scattered floor dispersals, calling sounds, and bodily movements desire reconsiderations of hope in precarity through a disorientation of place, association, scale, and language.


Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski May 2021

Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski

Theses and Dissertations

Ecosystem primary productivity halts when plants go dormant, and so the timing of dormancy as it relates to autumn phenology has been a focus of much interdisciplinary research. While monitoring plant phenology has its roots in directly observing specimens, digital sensors along with modern methods have also become a mainstay in phenology. Results from different methods often vary, so there is still a need to better understand how digital cameras record autumn phenology, especially in comparison with ground-based observations (Keenan et al. 2014). This study compared autumn phenology derived from direct ground observations with upward-facing fisheye photography, in the context …


Effects Of Precessional Forcing In The Early Stages Of The 100-K World, Molly Kingston May 2021

Effects Of Precessional Forcing In The Early Stages Of The 100-K World, Molly Kingston

Theses and Dissertations

Much of what we know about the Andes today comes from studying a heavily human-manufactured landscape. However, before the presence of human modification in this system (~13,000 years ago), past interglacial and glacial cycles, influenced by changes in Earth cycles (eccentricity, obliquity, and precession), were the cause of major landscape re-organization. The variability in intensity and duration of these events and the probable response of the plant community is not well understood. Very few records in South America extend far enough back in time to capture these changes. Those records that do exist, lack an independent chronology and instead rely …


Pre- And Post-Partum Observations Of Signature Whistle Characteristics Of The Bottlenose Dolphin (Tursiops Truncatus), Robert Dutchen Apr 2021

Pre- And Post-Partum Observations Of Signature Whistle Characteristics Of The Bottlenose Dolphin (Tursiops Truncatus), Robert Dutchen

Theses and Dissertations

This study analyzes whistle usage in an Atlantic bottlenose dolphin during birth. Findings show the mother produces two predominant whistle contours. Congruities between the whistles were compared and showed that the type 1 contour bears structural similarity to the first component of the type 2 contour, indicating combinatorial whistle construction.


Influence Of Group Change On Scent Marking In A Wild Population Of Verreaux’S Sifaka (Propithecus Verreauxi), Julia C. Dickerson Apr 2021

Influence Of Group Change On Scent Marking In A Wild Population Of Verreaux’S Sifaka (Propithecus Verreauxi), Julia C. Dickerson

Theses and Dissertations

This study analyzed scent marking rates of wild Verreaux’s sifaka during dispersals to investigate the impact of group changes on olfactory communication. Our results indicate that scent marking is affected by changes in group structure, but other methods of communication likely play a larger role in mediating group membership changes.


Body States Of Asian Elephants Within And Around Protected Areas In The Salakpra Wildlife Sanctuary, Kanchanaburi, Thailand, Caitlyn Thai Apr 2021

Body States Of Asian Elephants Within And Around Protected Areas In The Salakpra Wildlife Sanctuary, Kanchanaburi, Thailand, Caitlyn Thai

Theses and Dissertations

Researchers are becoming increasingly aware that studying a species’ landscape of fear or, more broadly, their emotional states, can better inform cognitive questions about how animals navigate their environments. Vigilance behaviors are one way to determine how certain species perceive and respond to risky situations. Due to rapid environmental change, large animals such as elephants are experiencing risky encounters with humans more often than ever before. This study aims to investigate Asian elephants’ expressions of body states and how they might regulate their behavior based on perceived environmental risk or change. Specifically, we investigated the behavioral responses of Asian elephants …


In Defense Of Plants: Salicylic Acid In A Host-Parasite-Pathogen System, Timothy Kyle Martin Apr 2021

In Defense Of Plants: Salicylic Acid In A Host-Parasite-Pathogen System, Timothy Kyle Martin

Theses and Dissertations

Cuscuta pentagona is an obligate parasitic plant that uses a specialized organ, known as a haustorium, to penetrate host xylem and phloem to absorb water and nutrients from its hosts. As holoparasites, they lack chloroplast and therefore cannot photosynthesize. Bidirectional movement at the haustoria raises the possibility that the parasite can transmit defense signals from one host to another, though in what form is unclear. The biotrophic feeding mode, lack of chloroplast, and bidirectional movement across the haustoria lead me to hypothesize that (1) C. pentagona as a shoot parasite would elicit a systemic acquired resistance response in a host …


The Mechanisms And Consequences Of Shrub Encroachment On The Virginia Barrier Islands, Lauren K. Wood Jan 2021

The Mechanisms And Consequences Of Shrub Encroachment On The Virginia Barrier Islands, Lauren K. Wood

Theses and Dissertations

Shrub encroachment is a global phenomenon driven by direct and indirect anthropogenic influence which alters plant communities and ecosystem function. Many studies have investigated drivers and consequences of woody plant establishment, but mesic landscapes are underrepresented in the literature. My objective was to assess the mechanisms of Morella cerifera encroachment into coastal mesic grassland, the potential for self-reinforcement, and consequences on community composition, nutrients, and landscape productivity. I studied temperature and water microclimate modification by Morella cerifera presence and removal to understand ecosystem engineering and community composition changes. Additionally, I examined the influence of shrubs on surrounding grassland species traits …


Water Clarity At The River-Estuary Transition Zone: A Comparative Study Of The James, Mattaponi, And Pamunkey Sub-Estuaries, Rachel Henderson Jan 2021

Water Clarity At The River-Estuary Transition Zone: A Comparative Study Of The James, Mattaponi, And Pamunkey Sub-Estuaries, Rachel Henderson

Theses and Dissertations

Water clarity is a key parameter for monitoring water quality and often used to assess habitat suitability for submerged aquatic vegetation (SAV). Light attenuation, a measure of water clarity, is impacted by colored dissolved organic matter (CDOM), and by suspended particulates which include living and non-living components. We anticipated that the relative importance of these factors in regulating light attenuation would vary among the upper portions of three sub-estuaries differing in morphometry, hydrology, and degree of human influence. The James is characterized by eutrophic conditions and high algal abundance, whereas the Mattaponi and Pamunkey exhibit lower phytoplankton production. The Mattaponi …


Phenotypic Characterization Of Table Mountain (Pinus Pungens) And Pitch Pine (Pinus Rigida) Hybrids Along An Elevational Gradient In The Blue Ridge Mountains, Virginia, Alexander L. Brown Jan 2021

Phenotypic Characterization Of Table Mountain (Pinus Pungens) And Pitch Pine (Pinus Rigida) Hybrids Along An Elevational Gradient In The Blue Ridge Mountains, Virginia, Alexander L. Brown

Theses and Dissertations

Hybridization has played a long-standing role in the evolution of both plant and animal species and allows for the sharing of genetic information between lineages. Here, potential hybridization of a species endemic to the Appalachian Mountains, Table Mountain pine (Pinus pungens), and pitch pine (Pinus rigida) was investigated along an elevational gradient, through the use of phenotypic measurements: cone length, cone width, and needle length. Phenotypes were used to identify hybrids in a three-tiered elevational sampling method at two sites in Shenandoah National Park with the use of linear discriminant analysis. It was found that hybridization …


Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin Jan 2021

Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin

Theses and Dissertations

Understanding habitat selection at multiple scales is an important step in guiding conservation programs and reversing species declines. This, however, is difficult for species that occupy early-successional habitats (ESH) due to a lack of accurate representation of shrub cover in publicly available land cover data. The Golden-winged Warbler (Vermivora chrysoptera; GWWA) is a threatened species of conservation concern and a flagship for ESH conservation. We used a novel, LIDAR-derived land cover classification that accurately identifies shrubs at a fine resolution (1m) to investigate how habitat composition and configuration influence GWWA site occupancy. We aggregated this same land cover …


Plant Communities In Dynamic Systems: How Disturbance Influences Coastal Plant Community Structure And Function, Joseph K. Brown Jan 2021

Plant Communities In Dynamic Systems: How Disturbance Influences Coastal Plant Community Structure And Function, Joseph K. Brown

Theses and Dissertations

As the climate continues to change it is difficult to predict how barrier island function will respond to global change drivers accompanying predicted climate change. Disturbance frequency and nutrient enrichment in coastal regions are drivers of plant community change that increase with climate change. Plant communities on barrier islands are not only tightly connected to barrier island function but are also some of the first communities affected by environmental change, making them a critical piece in understanding how current drivers of global change will impact the future of barrier islands. The objective of my dissertation was to observe and manipulate …


Successional Changes In Carbon Storage Are Sustained In A Temperate Forest Across Different Initiating Disturbances, Cameron Clay Jan 2021

Successional Changes In Carbon Storage Are Sustained In A Temperate Forest Across Different Initiating Disturbances, Cameron Clay

Theses and Dissertations

Managing forests for carbon (C) sequestration requires an understanding of how disturbance history shapes C pools and fluxes over successional time. At the University of Michigan Biological Station, we examined how two stand establishing disturbances influenced C pools and fluxes over 100+ years of succession, comparing these secondary forests with “legacy” late-successional stands encompassing ages and compositions that would be present in the absence of region-wide stand-replacing disturbance. Our work utilized measurements taken between 2014 and 2020 from separate experimental forest chronosequences initiated following clear-cut harvesting only or clear-cut harvesting and fire, along with three >130-yr-old late successional stands comprising …


A Spatiotemporal Assessment Of Fish Assemblage Response To Land-Use Change And The Evaluation Of Edna Metabarcoding For Describing Diverse Fish Communities, Timothy M. Owen Jan 2021

A Spatiotemporal Assessment Of Fish Assemblage Response To Land-Use Change And The Evaluation Of Edna Metabarcoding For Describing Diverse Fish Communities, Timothy M. Owen

Theses and Dissertations

Fish assemblages are often assessed as a biological proxy for environmental health. While humans value healthy environments for the ecosystem services and recreational opportunities they provide, it is increasingly evident that such resources can be paradoxically degraded by anthropogenic activities. In this investigation, we studied the relationship between different intensities of anthropogenic land-use change and habitat-driven fish assemblage response across multiple spatiotemporal scales. Secondarily, we explored the efficacy of eDNA metabarcoding against conventional electrofishing techniques for the purpose of describing complete fish communities. This study was conducted in the Tuckahoe Creek basin near Richmond, Virginia. This James River tributary serves …