Ecology and Evolutionary Biology Commons^™

Changes To The Nebraska Bird Review, Janis Paseka

Nebraska Bird Review

As of this issue, The Nebraska Bird Review has been in existence for 93 years, looking very much now as it did when it began in 1933. However, due to the increasing costs of printing and postage, there will be some changes in its future. Our newsletter, The Burrowing Owl, is already provided online to our members, in a user-friendly and informative form. Future issues of The Nebraska Bird Review will also utilize a digital format to offer a more timely and colorful publication.

This is the final issue for which Ross Silcock will be compiler of the seasonal …

Birds In Changing Landscapes: Community Diversity And Breeding Phenology, Lindsay Peria

Master's Theses

Humans are altering the environment in varied and widespread ways. Increasing urban and agricultural development causes changes to habitat and resource availability as well as changes to the sensory environment via light and noise pollution. Climate change also causes more extreme temperature anomalies, storms, and droughts that challenge birds in a multitude of ways. In this thesis, we assessed these impacts of these changes on a local and continental scale. In the first chapter, we assessed the impact of natural, anthropic, and structural characteristics of viticultural land on both taxonomic and structural avian diversity. Loss of habitat from agriculture is …

Impacts Of Nutrient Addition And Disturbance On Coastal Dune Arthropod Communities And Trophic Interactions, Kayla Beitzel

Graduate Theses and Dissertations (2019 - present)

Coastal dune ecosystems face ongoing threats from human-mediated disturbance and altered resource availability. Because these dunes provide critical habitat for many organisms, including shorebirds, beach mice, and arthropods, changes in disturbance regimes or resource availability can impact plant communities and higher trophic levels by altering plant richness and productivity, which in turn influence arthropod abundance and diversity. To examine how disturbance and nutrient addition affect arthropod communities, we established twenty 5×5 m plots on Dauphin Island, crossing mechanical disturbance with a 10 g m⁻² addition of nitrogen, phosphorus, and potassium, replicated across five experimental blocks. Arthropods were sampled using three …

Flower Color Variation And Its Maintenance: Experimental Ecology Of Serpentine-Adapted Leptosiphon Parviflorus Benth. (Polemoniaceae), Magdalene S. Lo

Master's Theses

Environmental heterogeneity can impose fluctuating selection pressures on species across space and time. If variations of a trait provide fitness benefits in certain environmental conditions but not others, these fitness tradeoffs under fluctuating selection could be a means of maintaining intraspecific variation. A common type of intraspecific variation is the production of anthocyanins, pigments responsible for red, pink, and blue colors in plants and that can also provide protection from abiotic stressors, such as water limitation and heavy metals. Leptosiphon parviflorus Benth. (Polemoniaceae, variable linanthus) is an annual wildflower whose individuals produce either pink or white flowers, and both flower …

Golden Eagle Predation Of Greater Sage-Grouse On Diamond Mountain Plateau, Victoria E. Thorpe

All Graduate Theses and Dissertations, Fall 2023 to Present

Predation and the perceived risk of predation can have major impacts on prey populations. Golden Eagles are considered one of the main predators of adult greater sage-grouse. Sage-grouse populations have been declining for decades throughout the West and wildlife managers are concerned about the impacts of golden eagles on sage-grouse. We investigated the nonconsumptive effects of golden eagles on sage-grouse by conducting observational surveys for golden eagles, sage-grouse, and other predators at sage-grouse lek sites near Vernal, Utah during the sage-grouse breeding season from 2022–2024. Additionally, we examined the prevalence of sage-grouse in golden eagle diet using DNA metabarcoding of …

Why The Long Face? The Distribution And Niche Of The Imperiled Narrow-Faced Kangaroo Rat (Dipodomys Venustus), Garrett L. Gimbel

Master's Theses

Distribution models provide a practical use case of connecting ecological niche theory with species’ occurrence and assemblages. By explicitly linking Hutchinson’s “niche space” with geographic space researchers can gain valuable information on a species’ niche characteristics and interactions, thereby informing conservation and management practices. The narrow-faced kangaroo rat (Dipodomys venustus) is a highly understudied kangaroo rat species endemic to the central coast of California and is an ideal species to explore niche theory in distribution modeling. Three subspecies are currently recognized: The Santa Cruz kangaroo rat (D. v. venustus), the elephant-eared kangaroo rat (D. v. …

Exploring Life History Trade-Offs In The Facultative Eusocial Bee Megalopta Genalis, Ana Gutiérrez Zuluaga

All Graduate Theses and Dissertations, Fall 2023 to Present

Organisms face many trade-offs in how to invest in these traits. One example is the trade-off between reproduction and longevity. Queens of social insects seem to escape this trade-off, producing thousands of eggs daily, despite having a longer lifespan than their workers. Some hypotheses have been proposed to explain this phenomenon, such as an evolutionary change in the molecular pathways that regulate queen investment in maintenance, growth, and reproduction. An alternative hypothesis suggests that the tradeoffs are rarely observed in queens due to the extensive resources provided by the help of workers. While these hypotheses have supporting evidence, they have …

Shifting Grounds: Knowledge, Power, And Place In Changing Western Rangelands, Molly C. Levy

Boise State University Theses and Dissertations

Public rangelands in the American West are sites of enduring contestation, where ecological change, competing values, and institutional complexity converge. Long-standing debates over livestock grazing, wildlife conservation, and land stewardship highlight fundamental questions of whose knowledge counts, whose authority is legitimate, and how resource use should adapt under shifting social and ecological conditions. This dissertation examines the intersections of knowledge, power, and land use in collaborative governance of contested landscapes. Using the Thunder Basin ecoregion (TBER) in northeastern Wyoming as a case study, I adopt a mixed-methods approach that integrates qualitative interviews, participant observation, archival research, and quantitative analysis of …

Arthropod Communities Associated With Endangered Physaria Thamnophila (Zapata Bladderpod) And Its Nurse Plants, Cesar Adrian Hinojosa

Theses and Dissertations

Physaria thamnophila is a federally endangered plant whose associated arthropods are understudied and poorly understood. This study surveyed environmental conditions and the arthropod community within the Arroyo Ramirez Tract of the Lower Rio Grande Valley National Wildlife Refuge, assessed which environmental factors influenced the arthropod community, and sought arthropod taxa statistically associated with Physaria thamnophila. Sticky cards and pitfall traps were deployed for a 7 day period, and vacuum samplings occurred quarterly over the span of a year to collect arthropods that were identified to order and family level for Coleoptera, Hymenoptera, and Lepidoptera. Biotic and abiotic surveys were performed …

Determination Of An Effective Natural Boxelder Bug (Boisea Trivittata) Repellent, Reyna Chavez

Theses and Dissertations

This study investigates the use of ecofriendly repellant alternatives to pest management to control boxelder bugs (Boisea trivittata). This bug gathers by the thousands on warm surfaces of exterior suburban homes during early fall and late spring. I determined bug repellency to turmeric oil (Curcuma longa), catnip (Nepeta cataria), citronella (Cymbopogon nardus), and lavender (Lavandula angustifolia). The treatments consisted of essential oils containing 20% methanol. All treatments demonstrated repellency of Boxelder bugs. Citronella was the most effective and had the highest level of repellency range of 90-99%. Catnip was the least effective with a repellency range of 63-82%.

Seagrass Preference Among Pinfish In The Lower Laguna Madre, Nathaniel Garza

Theses and Dissertations

Pinfish (Lagodon rhomboides) is a common estuarine fish species found from Massachusetts to the Yucatan, Mexico. As juveniles, pinfish spend a significant portion of their life in coastal seagrasses which provide both shelter from predators and food. Along the Texas coast, there are three major species of seagrass- turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme) and shoal grass (Halodule wrightii) that differ in structural complexity. The goal of this study was to determine if pinfish associate more with one seagrass species than the others. A year-long field study was completed using twelve sample sites in the Lower Laguna Madre, …

Explaining The Association Between Kittlitz's Murrelets (Brachyramphus Brevirostris) And Tidewater Glaciers: Which Habitat Factors Influence Spatial Distribution?, Brendan Higgins

Marine Biology

The Kittlitz’s Murrelet (Brachyramphus brevirostris) is a rare and cryptic seabird species that inhabits Alaska and Eastern Siberia. Populations of Kittlitz’s Murrelets that occur in areas with tidewater glaciers are tightly associated with tidewater glaciers and are only found in close proximity to them. The Kittlitz’s Murrelet is a species of conservation concern, but specific habitat associations are poorly understood. I conducted a multidisciplinary investigation to better understand associations between Kittlitz’s Murrelets and tidewater fjord physical structure. I used remotely sensed spectral indices to model change in abundance of suitable nesting habitat, and a long-term oceanographic dataset to quantify changes …

Investigating Mariculture-Associated Ecosystem Services Across The Northern Gulf Of Alaska, Josianne Haag

Oceanography

The rapid expansion of mariculture in Alaska can drive physical and chemical alterations to the marine environment by introducing non-native organisms or artificially increasing the biomass of a native species. Currently, the main mariculture products grown in Alaska include the Pacific oyster (Crassostrea gigas), the Pacific blue mussel (Mytilus trosuslus), and three macroalgae species: ribbon kelp (Alaria marginata), sugar kelp (Saccharina latissima), and bull kelp (Nereocystis luetkeana). This dissertation examines how these species can impact their surrounding environment to better inform management practices for this growing industry. This research characterized the resource use of C. gigas and M. trossulus seasonally …

Bricks, Bushes, And Bones: Urbanization Influence On Western Fence Lizard (Sceloporus Occidentalis) Morphology And Performance, Daisy P. Xiong

Electronic Theses, Projects, and Dissertations

With increasing urbanization due to rising human populations, organisms may be forced to adapt rapidly to changing environments. Urbanization is replacing natural surfaces with more impervious substrates which can result in morphological changes affecting organismal locomotion, then also impact fitness. This study compares urban and natural habitat impact on Western Fence Lizards (Sceloporus occidentalis) and their adaptations in such settings. We captured lizards from three locations in inland Southern California with both urbanized and natural habitats in order to compare the morphological differences between lizards, and then measured their performance to determine the possible impacts from their morphology. …

Plant Community Responses To Wildfire, Timber Thinning, And Bison Reintroduction On The Northern Great Plains, Ethan H. Van-Derpoel

All Theses

The Northern Great Plains (NGP) is one of the largest intact grasslands remaining in the world. These two studies examine a few of the ecological concerns on the NGP today. First, the woody encroachment of conifers into grasslands and the effects of wildfires. Second, the effects of bison (Bison bison) reintroduction on plant communities. In Chapter 1, this study aims to examine the effects of wildfire and mechanical timber thinning, using a two-by-two factorial design, on plant community responses and forage quality in the Bull Mountains area of central Montana, USA. We found that our treatments had varying …

Soundscapes Of Alaska's Arctic Coastal Plain: Implications For Wildlife, Maxwell Plichta

Biological Sciences

Passive acoustic monitoring is an effective tool for collecting baseline acoustic data in remote locations and for advancing our understanding of soundscapes, the sound that emanates from a landscape. Terrestrial Arctic soundscapes remain understudied. The Arctic Coastal Plain (ACP) of northern Alaska is an ecologically, culturally, and economically significant region, containing a mix of land-uses and management practices. This study leverages a spatially large (~8,000 km2), multi-year dataset of acoustic recordings and paired images collected across the ACP to investigate how natural and anthropogenic factors influence the soundscape (Chapter 2), and how acoustic metrics influence the behavior of caribou (Rangifer …

Testing For Local Adaptation In Sympatric Monkeyflowers Growing In Serpentine Seeps And Adjacent Rock Outcrops, Avin Niknafs

Master's Theses

Divergent selection across heterogeneous environments can drive ecological differentiation and the evolution of locally adapted populations, even when gene flow occurs. We tested for local adaptation between two sympatric monkeyflowers, Erythranthe guttata and E. serpentinicola (formerly Mimulus), which co-occur on the central coast of California. Erythranthe guttata is a perennial species primarily found in moist serpentine seeps, whereas E. serpentinicola is an annual species restricted to adjacent serpentine rock outcrops. Using a reciprocal transplant experiment with second-generation, greenhouse-derived seed, we quantified germination, survival, and reproductive success across contrasting microhabitats. We further evaluated the relative contributions of species, lineage, …

Robustness Of Network Inference Algorithms Under Network Class Misspecification, Roberto Ceja

Electronic Theses, Projects, and Dissertations

Inferring phylogenies in the presence of hybridization remains a difficult problem. As a result, many current methods for reconstructing phylogenetic networks are restricted to a simple class of networks known as level-1. This restriction arises from theoretical considerations rather than empirical evidence, with real data possibly arising from complex networks. In this work, we evaluate the robustness of two level-1 network inference methods, SNaQ and NANUQ+, through a simulation study, when the input data originates from a more complex network. Specifically, we investigate whether these methods can accurately recover important features of the true species network, such as the circular …

Taxonomy Of Endophytic Fungi Associated With Vallisneria Neotropicalis, Md. Arafat Rashid

Graduate Theses and Dissertations (2019 - present)

This study presents the first comprehensive taxonomic and ecological investigation of endophytic fungi (EF) associated with the submerged aquatic macrophyte Vallisneria neotropicalis in the southern United States. Over a 12 month period, from April 2023 to March 2024, leaf samples were collected from two distinct sites in Mobile Bay, Alabama a disturbed, brackish Causeway location and a cleaner, less impacted site at Meaher State Park. Using culture dependent methods, a total of 257 fungal endophytes were isolated from 1,200 leaf segments. All isolates belonged to the phylum Ascomycota, distributed across 3 classes, 6 orders, 10 families, and 19 taxa. The …

Drivers Of Faunal Communities In Isolated Wetlands: Local And Landscape Determinants Of Assemblages, Joshua Holbrook

All Dissertations

Ecological interactions such as predation are vital to shaping the distribution of organisms. For interactions to occur, organisms must undertake movement, such as dispersal, that places them in proximity to the organisms with which they may interact. Geographically isolated wetlands (GIW) are productive and biodiverse ecosystems, but little is known on broad geographic scales about the determinants of their fauna. Fishes have difficulty colonizing GIW, whereas amphibians and macroinvertebrates are adept overland dispersers – though they may be sensitive to top-down control by fishes. To better understand these phenomena, I sampled 10-20 wetlands each at nine regions in North and …