Digital Commons Network^™

Ecological Impacts Of Invasive Crayfish In A Naïve Riparian System, Gregor L. Hamilton

Biology ETDs

Aquatic and riparian food webs are inextricably linked. In deserts, they provide critical energy subsidies to surrounding terrestrial food webs, but these vital subsidies are not guaranteed; streams in arid lands are especially sensitive to perturbations. In this dissertation, I investigated the role of an oft-cited threat to stream communities in the lower Colorado River basin: non-native crayfish. I contributed to methodologies in passive integrated transponder use and length-weight relationships in crayfish to aid future research. I leveraged stable isotope analysis of δ¹⁵N, δ¹³C, and δ²H to understand crayfish role in the food webs. …

Comparison Of Daily Activity Patterns Across Seasons Using Gps Telemetry And Camera Trap Data For A Widespread Mammal, David W. Wolfson, Peter E. Schlichting, Raoul K. Boughton, Ryan S. Miller, Kurt C. Vercauteren, Jesse S. Lewis

USDA Wildlife Services: Staff Publications

Daily activity patterns of animals can be dynamic across seasons in response to changing environmental conditions. Daily activity, though, has rarely been evaluated in relation to multiple factors (for example, seasons, demographics, and data collection methods), which could be important for understanding what drives activity patterns. Here, we evaluated the daily activity patterns of a widespread invasive species, wild pigs (Sus scrofa), across two ecologically different study areas at Buck Island Ranch, Florida, and Tejon Ranch, California (United States), from 2015 to 2018. Using GPS telemetry data (62 individuals in Florida, 21 individuals in California) and detections from …

Distribution Patterns Of The Invasive Mussel Arcuatula Senhousia In Mission Bay, San Diego, California: Effects Of Sediment Grain Size And Byssus Thread Production On Predation, Samantha Ahlman

Theses

The ability of bivalves to avoid predation by using defensive behaviors such as burrowing and byssus production may vary depending on the sediment characteristics of a given habitat. The varying sediment characteristics that change with water velocity within estuaries may influence the distribution of bivalves and limit them to areas that optimize their ability to defend against predators. We examined the distribution patterns of the invasive Asian date mussel Arcuatula senhousia relative to the sediment grain size distribution in Mission Bay, an urban estuary located in San Diego, California, USA. Mussels and sediment were collected using an Ekman grab at …

Optimizing Management Of Invasions In An Uncertain World Using Dynamic Spatial Models, Kim M. Pepin, Amy J. Davis, Rebecca S. Epanchin-Niell, Andrew M. Gormley, Joslin L. Moore, Timothy J. Smyser, H. Bradley Shaffer, William L. Kendall, Katriona Shea, Michael C. Runge, Sophie Mckee

USDA Wildlife Services: Staff Publications

Dispersal drives invasion dynamics of nonnative species and pathogens. Applying knowledge of dispersal to optimize the management of invasions can mean the difference between a failed and a successful control program and dramatically improve the return on investment of control efforts. A common approach to identifying optimal management solutions for invasions is to optimize dynamic spatial models that incorporate dispersal. Optimizing these spatial models can be very challenging because the interaction of time, space, and uncertainty rapidly amplifies the number of dimensions being considered. Addressing such problems requires advances in and the integration of techniques from multiple fields, including ecology, …

Texas Hunters’ Perceptions Regarding The Acceptability Of Toxicants To Control Wild Pig Populations, Keith M. Carlisle, Sophie Mckee, Hailey E. Ellis, Lauren M. Jaebker, John M. Tomeček, Alan D. Bright, Rachael L. Connally, Maureen G. Frank, Stephanie A. Shwiff

Human–Wildlife Interactions

Wild pigs (Sus scrofa) are an invasive species in the United States. They damage agriculture, degrade water quality and ecological communities, and host a number of viruses, parasites, and bacteria transmissible to humans and animals. In states such as Texas, USA, where wild pigs cause extensive damage to agriculture and property, officials have considered allowing for the use of toxicants to control wild pig populations. To provide decision-makers with information regarding stakeholders’ perceptions of the use of toxicants to control wild pigs, we surveyed Texas hunters in 2019 to assess the level of acceptance of a hypothetical wild …

Corbicula Fluminea Effects On Survival, Growth, And Drift Of Juvenile Lampsilis Siliquoidea In Laboratory Exposures, Allison Nicole Sieja

MSU Graduate Theses

The Asian clam, Corbicula fluminea, is an invasive species that is abundant and often co-occurs with native freshwater mussels. Corbicula is widely suspected of having negative effects on native mussels, but few studies have empirically tested this hypothesis. I used laboratory experiments to evaluate how adult Corbicula affected the survivorship, growth, and drift of juvenile Lampsilis siliquoidea. Survival and growth of newly metamorphosed mussels were tested in downwelling flow-through chambers with glass-bead substrate. Treatments were control (no clams), small adult clams, or large adult clams. After 28 days, large clams slightly but significantly reduced the number of juveniles …

Weedy Relations: Narratives Of Invasion And Intimacy With Tamarisk In The Chihuahuan Desert, Shannon S. Pepper

Geography ETDs

Tamarix spp., also known as salt cedar or tamarisk, is a shrub that has garnered a notorious reputation in North America as an invasive plant, with widespread policy and research advocating for its eradication in the Southwest U.S. and Northern Mexico. This study examines both governmental conservation documents and news articles to investigate narrative trends on tamarisk in the Southwestern U.S. and Northern Mexico as a contiguous region (the Chihuahuan Desert), expanding on current research to include transborder effects on the perception and management of introduced species. This paper asks: In the last 25 years, how has the movement, …

Quantifying The Effects Of Early Competition On Niche Specialization: A Natural Experiment In A Restored System, Christy Nicole Wails

Graduate Research Theses & Dissertations

Islands support the greatest numbers of endemic species but are highly vulnerable to human activities. In particular, the introduction of invasive, predatory mammals (e.g., rodents) has resulted in sharp declines of island fauna due to a lack of evolved behavioral capacities to avoid depredation. Because of this, invasive species are considered to be one of the most detrimental impacts to biodiversity. To combat this biodiversity loss, the eradication of invasive mammals is now a primary conservation tool, with > 700 attempts globally. However, mammal eradications are predicated on the assumption that islands will naturally return to their pre-invaded condition. Yet many …

Understanding Patterns And Functional Impacts Of An Invasive Tree And Its Biological Control In A Riparian System, Annie L. Henry

Electronic Theses and Dissertations

Invasive species have become an inextricable part of the landscape, particularly in riparian plant communities, and removal is often a key component of restoration programs. Biological control (biocontrol) is a method of removal that is often both efficient and effective. However, the impact of biocontrol on target species and indirect effects from invasive species removal can be hard to predict. While monitoring the impact of invasive species removal usually involves some species-based assessment such as changes in diversity, historically dominant species or native species, these strategies do not typically provide insight into the mechanisms underlying plant community response to removal. …

Rapid Quantification Of Biofouling With An Inexpensive, Underwater Camera And Image Analysis, Matthew R. First, Scott C. Riley, Kazi Aminul Islam, Victoria Hill, Jiang Li, Richard C. Zimmerman, Lisa A. Drake

Electrical & Computer Engineering Faculty Publications

To reduce the transport of potentially invasive species on ships' submerged surfaces, rapid-and accurate-estimates of biofouling are needed so shipowners and regulators can effectively assess and manage biofouling. This pilot study developed a model approach for that task. First, photographic images were collected in situ with a submersible, inexpensive pocket camera. These images were used to develop image processing algorithms and train machine learning models to classify images containing natural assemblages of fouling organisms. All of the algorithms and models were implemented in a widely available software package (MATLAB^©). Initially, an unsupervised clustering model was used, and three …

Comparison Of Native And Non-Native Predator Consumption Rates And Prey Avoidance Behavior In North America And Europe, Ayse Gül Ünlü, John J. Obrycki, Roman Bucher

Entomology Faculty Publications

Novel predator–prey interactions can contribute to the invasion success of non-native predators. For example, native prey can fail to recognize and avoid non-native predators due to a lack of co-evolutionary history and cue dissimilarity with native predators. This might result in a competitive advantage for non-native predators. Numerous lady beetle species were globally redistributed as biological control agents against aphids, resulting in novel predator–prey interactions. Here, we investigated the strength of avoidance behavior of the pea aphid (Acyrthosiphon pisum) toward chemical cues of native lady beetles and non-native Asian Harmonia axyridis and European Coccinella septempunctata and Hippodamia variegata …

Connecting The Social And Spatial Behaviors Of A Territorial Species (Anolis Carolinensis), Jordan M. Bush

Doctoral Dissertations

Why animals live where they do is a key question in ecology and evolution. An individual’s home range determines the resources they have access to, conspecifics they encounter, and predators and pitfalls they must avoid. Home range behaviors also have an inherently social component; where animals live affects the rivals they compete with and the mates they have access to. This is especially true in territorial species, as defensive displays make up a large portion of their social behaviors. In this dissertation, I sought to understand how territorial behaviors affect the social lives of the green anole lizard (Anolis …

Ecology Of The Roseau Cane Scale (Nipponaclerda Biwakoensis, Hemiptera: Aclerdidae) In Coastal Louisiana, Leslie Alejandra Aviles Lopez

LSU Master's Theses

Common reed, Phragmites australis, is the dominant plant in the Mississippi River Delta (MRD), Louisiana. Phragmites australis stands reduce soil erosion from wave action, protect the oil infrastructure, and freshwater habitats. In the fall of 2016, widespread reed die-backs in the MRD were associated with outbreaks of an invasive scale Nipponaclerda biwakoensis (Hemiptera: Aclerdidae). Due to the recent detection of the scale, there was limited knowledge of its ecology in the adventive range, and its impacts on P. australis lineages. Therefore, the objectives of my thesis were to determine (1) the host specificity of the N. biwakoensis in important economic …

Photographic Validation Of Target Versus Nontarget Take Of Brown Treesnake Baits, Shane R. Siers, Aaron B. Shiels, Cynthia G. Payne, Francinem M. Chlarson, Craig S. Clark, Stephen M. Mosher

USDA Wildlife Services: Staff Publications

Use of toxic baits or other tools for managing nuisance species must ensure that the species of interest is adequately targeted while exposure to nontarget species is minimized. Nontarget takes of acetaminophen‐laced baits for control of invasive brown treesnakes (Boiga irregularis) on Guam may put those animals at risk of lethal intoxication and render the bait unavailable to the intended target species. We used wildlife cameras to identify species removing toxic and nontoxic baits from brown treesnake bait stations designed to exclude nontarget taxa in 2015 and 2016. Throughout various sites and habitat types, and balanced by season (wet vs. …

Effect Of Locality Recognition On Aggressive Behavior In The Red Swamp Crayfish, Procambarus Clarkii, Brett K. Muramoto, Tyler Farley

Seaver College Research And Scholarly Achievement Symposium

Climate change affects habitat globally, facilitating the expansion and rapid proliferation of invasive species which damage the newly invaded ecosystem. Intraspecific aggression among an invasive species is an important focus in ecological studies because it can contribute to their overall success as invaders. The crayfish species, Procambarus clarkii, inhabits freshwater streams in the Santa Monica Mountains (Los Angeles, CA) as an aggressive invasive predator. These invasive crayfish are well known for their highly aggressive interactions with conspecifics. It has been shown that body size, temperature, sex, and level of hunger influence their levels of aggression. However, there is a …

Effects Of The Invasive Asian Shore Crab, Hemigrapsus Sanguineus, On New England Trophic Cascade: Diet And Predation, Madison Bradley

Writing Across the Curriculum

Trophic cascades occur when the community structure is influenced by indirect effects of predation on the lower trophic levels. The trophic cascade can be disrupted when an invasive species is introduced. The Asian shore crab, Hemigrapsus sanguineus has invaded ecosystems in New England and we predict this invasion will negatively affect the classic New England trophic cascade. By the predation indirectly affecting lower trophic levels, H. sanguineus can influence the community structure and diversity at the lower levels. To understand the trophic cascade, we manipulated the food source and competitors in four different mini-ecosystems. By introducing H. sanguineus into an …

Quantifying Early Risks Of Species Invasions: Factors Regulating South To North Bivalve Colonization Of Novel Habitats, Zhiqiang Xia

Electronic Theses and Dissertations

Management of species invasions ideally requires early detection of species at low abundance, which is often challenging for traditional methods. Environmental DNA (eDNA) provides a promising tool with enhanced sensitivity relative to traditional methods. As an emerging method, however, detection of species at low abundance based on eDNA needs to be optimized to improve detection rate and reduce false negatives. I conducted a meta-analysis, the results of which suggested the significance of using the highly sensitive PCR method and extensive sampling (i.e., replicates sampling and large water volume) to improve detection rate in eDNA-based, low-abundance species detection programs. Needs for …

Beta Diversity Provides Evidence Of Niche Based Assembly In Temperate Forest Understory Assemblages Of Mississippi, David Steven Mason

Theses and Dissertations

Assembly is a process that shapes the abundance and identity of species in a community. Niche and neutral theory explain assembly processes with mechanisms driven by either species differences, or functional equivalence and stochastic dispersal. In 2017 I sampled vegetation and environmental variables at 59 sites in the Noxubee National Wildlife Refuge and Tombigbee National Forest of Mississippi to explore forest understory community assembly. I developed and assessed a framework of predictions concerning general patterns and underlying mechanism. Evidence of dispersal limitation and functional equivalence were expected under neutral theory. Local environmental characteristics, surrounding landscape variables, and fire were significant …

Using Introduced Species Of Anolis Lizards To Test Adaptive Radiation Theory, James T. Stroud

FIU Electronic Theses and Dissertations

Adaptive radiation – the proliferation of species from a single ancestor and diversification into many ecologically different forms – has long been heralded as an important process in the generation of phenotypic diversity. However, the early stages of adaptive radiation are notoriously elusive to observe and study. In this dissertation, I capitalize on communities of introduced non-native Anolis lizards as analogues of early stage adaptive radiations. In Chapter II, I begin by reviewing the concept of “ecological opportunity” – a classic hypothesis put forward as a potential key to understanding when and how adaptive radiation occurs. In Chapter III, I …

Implications Of Body Size And Habitat Distribution Of Carcinus Maenas For Predation On Mytilus Edulis In The Gulf Of Maine, Mckenzie Thompson

Honors College

The blue mussel, Mytilus edulis, is a commercially important species along the Gulf of Maine. Its rapid decline in population size over the last forty years has led many researchers to question if the invasive green crab, Carcinus maenas, is affecting its distribution. The increase in annual mean water temperature, due to global climate change, has led many to fear an expansion of the green crab’s range and an increase in population density among areas they currently inhabit. The Damariscotta River in Walpole, Maine offers a unique thermal gradient to study the effects of temperature on green crab distribution, abundance, …

Habitat Use And Behaviours Of Introduced Muscovy Ducks (Cairina Moschata) In Urban And Suburban Environments, Joni Downs, Rebecca Loraamm, James Howard Anderson Jr., Jacqueline Perry, Jessica Bullock

Suburban Sustainability

Muscovy ducks (Cairina moschata) are native to South America, Central America, and Mexico. The species is commonly domesticated and raised for meat across the globe. Escaped or intentionally introduced populations have become established in many suburban areas, although they are little studied. A total of 642 individual time-activity budgets were collected for invasive Muscovy ducks in Tampa, Florida, USA, in order to quantify habitat use and behavioural patterns. Muscovy ducks utilized a variety of cover types, including open water, shoreline, grass, tree, shrub, and urban habitats. Muscovy ducks foraged by dabbling, gleaning, grazing, and probing, while occasionally obtaining, …

The Effect Of Site Characteristics On The Reproductive Output Of Lesser Celandine (Ranunculus Ficaria), Justin P. Kermack

ETD Archive

Ranunculus ficaria L., an ephemeral perennial invasive plant brought over from Europe, is becoming widespread throughout the Northeastern United States. This herbaceous buttercup is able to create extensive dense mats that limit native species growth. Taking advantage of an early growing season and rapid reproduction rates, this species can create dense monocultures, which threatens native communities and ecosystems. Elimination of native spring ephemerals results in decreased biodiversity. A better understanding of how R. ficaria responds to site characteristics is needed to prioritize management efforts toward high-risk sites.

Ranunculus ficaria abundance and reproductive output (seed, bulbil and tuber production rates) were …

Effective Dose And Persistence Of Rhodamine-B In Wild Pig Vibrissae, Sarah C. Webster, Fred L. Cunningham, John C. Kilgo, Mark A. Vukovich, Olin E. Rhodes Jr., James C. Beasley

USDA Wildlife Services: Staff Publications

As a result of substantial ecological and economic damage attributed to wild pigs (Sus scrofa), there is international interest in using pharmaceutical baits to control populations. To assess the efficacy and specificity of baiting programs, chemical biomarkers can be used to evaluate uptake of pharmaceutical baits. Rhodamine B (RB) is known to be an effective biomarker in wild pigs. However, significant data gaps exist regarding the minimum effective dosage and persistence of RB in wild pigs. We used a controlled doubleblind study experiment conducted in spring of 2014 on the Savannah River Site, Aiken, South Carolina, USA, wherein …

Effective Dose And Persistence Of Rhodamine-B In Wild Pig Vibrissae, Sarah C. Webster, Fred L. Cunningham, John C. Kilgo, Mark A. Vukovich, Olin E. Rhodes Jr., James C. Beasley

USDA Wildlife Services: Staff Publications

As a result of substantial ecological and economic damage attributed to wild pigs (Sus scrofa), there is international interest in using pharmaceutical baits to control populations. To assess the efficacy and specificity of baiting programs, chemical biomarkers can be used to evaluate uptake of pharmaceutical baits. Rhodamine B (RB) is known to be an effective biomarker in wild pigs. However, significant data gaps exist regarding the minimum effective dosage and persistence of RB in wild pigs. We used a controlled doubleblind study experiment conducted in spring of 2014 on the Savannah River Site, Aiken, South Carolina, USA, wherein …

Evolutionary Responses Of Invasive Grass Species To Variation In Precipitation And Soil Nitrogen, Monica A. Nguyen, Amy E. Ortega, Quoc L. Nguyen, Sarah Kimball, Michael L. Goulden, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1.Global climate models suggest that many ecosystems will experience reduced precipitation over the next century and the consequences for invasive plant performance are largely unknown. Annual invasive species may be able to quickly evolve traits associated with drought escape or tolerance through rapid genetic changes.

2.We investigated the influence of five years of water and nitrogen manipulations on trait values in a southern California grassland system. Seeds from two annual grass species (Avena barbata, Bromus madritensis) were collected from experimental plots and grown in a common environment over two generations. We measured 14 physiological, morphological, phenological, and …

Effects Of Short-Term Soil Conditioning By Cheatgrass And Western Wheatgrass, James J. O'Connor, Janet S. Prevey

The Prairie Naturalist

The exotic grass Bromus tectorum (cheatgrass) is a ubiquitous invader in the western USA. Cheatgrass is a proficient competitor, frequently displacing native plants, forming monotypic stands and reducing biodiversity in ecosystems it invades. Our experiment tested whether short-term soil modification by cheatgrass and a predominant native grass, Pascopyrum smithii (western wheatgrass), affected subsequent growth of both species. We compared productivity of cheatgrass and western wheatgrass by harvesting aboveground biomass of plants grown in either cheatgrass- or western wheatgrass-conditioned soils over two simulated growing seasons. Results indicated that cheatgrass soils do not inhibit the productivity of the native grass, but do …

Allelopathy In The Non-Native Macrophyte, Myriophyllum Spicatum And Its Influence On Trophic Dynamics In Aquatic Systems, Daniel J. Sullivan

Theses and Dissertations

Non-native macrophytes structurally impact aquatic assemblages, yet little is known regarding how they influence energy pathways in freshwater ecosystems. Allelopathy in Eurasian watermilfoil- Myriophyllum spicatum has been shown to target basal epiphytic organisms resulting in differences in assemblage structure of colonizing epiphyton between M. spicatum and native M. sibiricum. I conducted a growth chamber experiment to investigate the hypothesis that differences in assemblage structure of colonizing epiphyton between these two macrophytes influence trophic dynamics within aquatic systems. My data suggest M. spicatum produces higher concentrations of allelochemicals, resulting in a more diverse epiphytic assemblage compared to M. sibiricum. This could …

Factors Influencing Asiatic Oak Weevil Interactions With Native Ecosystem Engineers Over Time, Daniel Rothschild O'Brien

Theses

I sought to build a model to predict current and future abundance of Asiatic oak weevil (Coleoptera: Curculionidae: Cyrtepistomus castaneus) by using the relative abundance of leaf tying and leaf rolling caterpillars. The Asiatic oak weevil is an exotic species that has been observed inside leaf ties and leaf rolls made by native Lepidoptera caterpillars. Chapter one is a review of the known relationships between animal constructs and exotic species. Within this review I transition from natural structures, to animal architects, and to ecosystem engineers and how they have a population dynamic impact on the invasive species. I also discuss …

Utilization Of The Invasive Alga Gracilaria Vermiculophylla (Ohmi) Papenfuss By The Native Mud Snail Ilyanassa Obsoleta (Say), Michele Guidone, Christine Newton, Carol S. Thornber

Biology Faculty Publications

The recent invasions of the red alga, Gracilaria vermiculophylla, to the Atlantic and Eastern Pacific Oceans have the potential to significantly alter intertidal and subtidal soft sediment communities. In particular, G. vermiculophylla increases habitat complexity and provides a novel hard substrate in an otherwise two dimensional habitat. Following our observations that the native omnivorous mud snail Ilyanassa obsoleta utilizes G. vermiculophylla for egg capsule deposition, our field surveys demonstrated that the in situ abundance of egg capsules on G. vermiculophylla matched abundances on a native alga Ceramium virgatumandwere at least 11–50 times greater than on all other co-occurring macrophytes. Additionally, …

The Effects Of Invasive Plants On Biodiversity Across Spatial Scales, Kristin Irene Powell

All Theses and Dissertations (ETDs)

Although introduced plant species are often considered to be one of the most notable anthropogenic threats to biodiversity, their influence on biodiversity remains controversial. Some studies have shown large declines in biodiversity in plant-invaded areas, whereas others have noted that plant invasions are rarely implicated as the cause of species extinctions. This dissertation aims to synthesize this seemingly conflicting literature on the effects of invasive plants on biodiversity. The overarching hypothesis in this research is that the effect of invasive plant species on biodiversity is scale-dependent, and the discrepancy among studies can be explained by a difference in the scales …