Digital Commons Network^™

The Fate Of Anthropogenic Nitrogen Along Hydrologic Continuums: Patterns Of Transformation And Recycling In A Eutrophic Lake And Coastal Marine Sediments, Daniel K. Hoffman

Browse all Theses and Dissertations

Eutrophication of aquatic systems can have cascading effects along hydrological continua from watersheds to coasts that result in impaired ecosystem health. In freshwater systems, blooms of toxic, non-nitrogen (N) fixing cyanobacteria (cyanoHABs), such as Microcystis, proliferate due to external loading of chemically reduced forms of N (e.g., ammonium (NH4+) and urea), which promote growth and toxin production. In coastal marine systems, nutrient loading can promote harmful algae blooms and threaten vulnerable, native vegetation, such as seagrasses, which provide valuable ecosystem services but are under threat globally from anthropogenic stressors. This dissertation focuses on NH4+ cycling in the water column of …

Anthrax Event Detection: Analysis Of Public Opinion Using Twitter During Anthrax Scares, The Mueller Investigation, And North Korean Threats, Michele E. Miller

Browse all Theses and Dissertations

When people allow fear to drive their decision making, they often make decisions that do more harm than good. Examples of this include stocking up on ciprofloxacin, flooding doctors’ offices and buying black market antibiotics after the anthrax attacks of 2001. Therefore, it is important to be able to address what people are saying when another anthrax attack occurs. Supervised and unsupervised machine learning methodologies can be utilized to detect an event, classify the tweets by event, and to determine the main topics of discussion. Over the period of data collection, twenty events were detected. Three of these events concerned …

Soil Carbon Dynamics And Greenhouse Gas Emissions In Conservation Tillage Systems At Multiple Scales, Yawen Huang

Theses and Dissertations--Plant and Soil Sciences

Conservation tillage practices like no-tillage and reduced tillage have been widely implemented worldwide, with expectations they would provide multiple benefits (e.g., yield enhancement and soil carbon sequestration) for food security and climate adaptation and mitigation. However, the adoption of conservation tillage faces both opportunities and challenges. A knowledge gap still exists regarding the effects of conservation tillage on the carbon cycle in agroecosystems. This dissertation reflects a comprehensive evaluation of conservation tillage at multiple scales using an integrated systems approach, a combination of data synthesis, the agriculture ecosystem model, and field observations and measurements. I first conducted a meta-analysis to …

Comparative Evaluation Of Machine Learning Models For Groundwater Quality Assessment, Shine Bedi, Ashok Samal, Chittaranjan Ray, Daniel D. Snow

School of Computing: Faculty Publications

Contamination from pesticides and nitrate in groundwater is a significant threat to water quality in general and agriculturally intensive regions in particular. Three widely used machine learning models, namely, artificial neural networks (ANN), support vector machines (SVM), and extreme gradient boosting (XGB), were evaluated for their efficacy in predicting contamination levels using sparse data with non-linear relationships. The predictive ability of the models was assessed using a dataset consisting of 303 wells across 12 Midwestern states in the USA. Multiple hydrogeologic, water quality, and land use features were chosen as the independent variables, and classes were based on measured concentration …

Assessing The Hierarchy Of Long-Term Environmental Controls On Diatom Communities Of Yellowstone National Park Using Lacustrine Sediment Records, Victoria Chraibi, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

An ecosystem’s ability to maintain structure and function following disturbance, defined as resilience, is influenced by a hierarchy of environmental controls, including climate, surface cover, and ecological relationships that shape biological community composition and productivity. This study examined lacustrine sediment records of naturally fishless lakes in Yellowstone National Park to reconstruct the response of aquatic communities to climate and trophic cascades from fish stocking. Sediment records of diatom algae did not exhibit a distinct response to fish stocking in terms of assemblage or algal productivity. Instead, 3 of 4 lakes underwent a shift to dominance by benthic diatom species from …

Transformative Education In Agroecology: Student, Teacher, And Client Involvement In Co-Learning, Charles A. Francis, Anna Marie Nicolaysen, Geir Lieblein, Tor Arvid Breland

Department of Agronomy and Horticulture: Faculty Publications

Educational methods have evolved rapidly in agroecology, which is a complex and holistic field without a long history or the formal tradition of any single academic discipline. Definitions of agroecology have evolved from its initial conception as a marriage of agriculture with ecology, to an aggregation of different paths including science, practices, and movements, and recently as a broad appreciation of the ecology of food systems. In contrast with traditional courses that begin with a history of the discipline and review the contributions of early leaders, we have embraced phenomenology to firmly establish roots in students’ learning through their experiences …

Invasive Wild Pigs As Primary Nest Predators For Wild Turkeys, Heather N. Sanders, David G. Hewitt, Humberto L. Perotto-Baldivieso, Kurt C. Vercauteren, Nathan P. Snow

United States Department of Agriculture Wildlife Services: Staff Publications

Depredation of wild turkey (Meleagris gallopavo) nests is a leading cause of reduced recruitment for the recovering and iconic game species. invasive wild pigs (Sus scrofa) are known to depredate nests, and have been expanding throughout the distributed range of wild turkeys in north America. We sought to gain better insight on the magnitude of wild pigs depredating wild turkey nests. We constructed simulated wild turkey nests throughout the home ranges of 20 GPS-collared wild pigs to evaluate nest depredation relative to three periods within the nesting season (i.e., early, peak, and late) and two nest densities (moderate = 12.5-25 …

Effect Of Vaccination With A Novel Gnrh-Based Immunocontraceptive On Immune Responses And Fertility In Rats, Giovanna Massei, D. Cowan, Douglas C. Eckery, Richard E. Mauldin, M. Gomm, P. Rochaix, Fergal Hill, R. Pinkham, Laura A. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

1. As human-wildlife conflicts increase worldwide, novel methods are required for mitigating these conflicts. Fertility control, based on immunocontraceptives, has emerged as an alternative option to lethal methods for managing wildlife.

2. Immunocontraceptives are vaccines that generate an immune response to key components of an animal's reproductive system. Some of these vaccines target the gonadotropin-releasing hormone (GnRH) and have been used successfully as contraceptives for many wildlife species. However, the need to capture animals for treatment limits the field applications of injectable vaccines. The availability of orally delivered immunocontraceptives would increase the breadth of applications of fertility control for wildlife …

Ecological Drivers Of African Swine Fever Virus Persistence In Wild Boar Populations: Insight For Control, Kim M. Pepin, Andrew J. Golnar, Zaid Abdo, Tomasz Podgórski

United States Department of Agriculture Wildlife Services: Staff Publications

Environmental sources of infection can play a primary role in shaping epidemiological dynamics; however, the relative impact of environmental transmission on host-pathogen systems is rarely estimated. We developed and fit a spatially explicit model of African swine fever virus (ASFV) in wild boar to estimate what proportion of carcassbased transmission is contributing to the low-level persistence of ASFV in Eastern European wild boar. Our model was developed based on ecological insight and data from field studies of ASFV and wild boar in Eastern Poland. We predicted that carcass- based transmission would play a substantial role in persistence, especially in low-density …

Influenza A Viruses In Peridomestic Mammals, J. Jeffrey Root, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

During recent years, serological evidence has shown that a number of peridomestic mammals (e.g., those commonly found in or around human structures) are naturally exposed to influenza A viruses (IAVs). In addition, experimental studies have demonstrated that many of these species can successfully replicate several different IAVs, including IAVs of high consequence to public or agricultural health. The replication of some IAVs within this group of mammals could have implications for biosecurity associated with poultry production and live bird markets in some regions of the world. Given this evidence, the need for further study and understanding of the role that …

Invasive Rat Establishment And Changes In Small Mammal Populations On Caribbean Islands Following Two Hurricanes, Aaron B. Shiels, Claudia D. Lombard, Laura Shiels, Zandy Hillis-Starr

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive mammals, particularly black rats (Rattus rattus), house mice (Mus musculus), and mongoose (Herpestes auropunctatus) are established on many tropical islands and threaten natural resources such as native birds, sea turtles, lizards, invertebrates, and plants. St. Croix (U.S. Virgin Islands, Caribbean) has a diversity of natural resources being protected from invasive mammals by U.S. conservation agencies. Sandy Point National Wildlife Refuge and Buck Island Reef National Monument receive among the highest density of nesting sea turtles in the region, including annual nesting populations of 50e250 leatherbacks (Dermochelys coriacea), 25e80 hawksbills (Eretmochelys imbricata), and 100e250 green turtles (Chelonia mydas). Buck Island …

Effects Of Wild Pig Disturbance On Forest Vegetation And Soils, Steven M. Gray, Gary J. Roloff, Daniel B. Kramer, Dwayne R. Etter, Kurt C. Vercauteren, Robert A. Montgomery

United States Department of Agriculture Wildlife Services: Staff Publications

In North America, wild pigs (Sus scrofa; feral pigs, feral swine, wild boars) are a widespread exotic species capable of creating large‐scale biotic and abiotic landscape perturbations. Quantification of wild pig environmental effects has been particularly problematic in northern climates, where they occur only recently as localized populations at low densities. Between 2016 and 2017, we assessed short‐term (within ~2 yrs of disturbance) effects of a low‐density wild pig population on forest features in the central Lower Peninsula of Michigan, USA. We identified 16 8‐ha sites using global positioning system locations from 7 radio‐collared wild pigs for sampling.Within each …

Placebo Oral Rabies Vaccine Bait Uptake By Small Indian Mongooses (Herpestes Auropunctatus) In Southwestern Puerto Rico, Are R. Berentsen, Richard B. Chipman, Kathleen M. Nelson, Kenneth S. Gruver, Frank Boyd, Steven F. Volker, Amy J. Davis, Ad Vos, Steffen Ortmann, Amy Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

The small Indian mongoose (Herpestes auropunctatus) is a rabies reservoir in areas of the Caribbean including Puerto Rico, but no rabies vaccination program targeting this host exists. We used two derivatives of iophenoxic acid (IPA) to evaluate placebo oral rabies vaccine bait uptake by mongooses in southwestern Puerto Rico. We hand-distributed baits at an application rate of 200 baits/km² at three, 400 ha, sites during autumn 2016 and spring 2017. Each site contained 90–100 cage traps in a 100 ha central trapping area. We used ethyl-IPA as a biological marker during the autumn and methyl-IPA during the …

Bird-Livestock Interactions Associated With Increased Cattle Fecal Shedding Of Ciprofloxacin-Resistant Escherichia Coli Within Feedlots In The United States, James C. Carlson, Jeffrey C. Chandler, Bledar Bisha, Jeffrey T. Lejeune, Thomas E. Wittum

United States Department of Agriculture Wildlife Services: Staff Publications

This research study was conducted to determine if bird depredation in feedlots is associated with the prevalence of ciprofloxacin-resistant Escherichia coli in cattle and to determine if removal of invasive bird species could be an effective management strategy to help reduce ciprofloxacin-resistant E. coliin cattle within the United States. european starlings (Sturnus vulgaris) were collected from feedlots within multiple geographic regions within the United States and european starlings within all regions tested positive for ciprofloxacin-resistant E. coli, but prevalence differed by region. Total number of birds on feedlots were positively associated with increased cattle fecal shedding of ciprofloxacin-resistant E. coli. …

Fish-Eating Birds On Catfish Ponds In The Mississippi Delta, Paul Burr, Jimmy Avery, Garrett Street, Bronson Strickland, Brian Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Catfish acreage in the Mississippi Delta has significantly declined in the past two decades, but cormorant density on catfish ponds has remained the same. One possible explanation is that there are fewer cormorants in the region, and this is supported with decreasing roost counts. Cormorant roost harassment can be even more effective today than in the past, because there is less aquaculture acreage to protect and fewer cormorants to move. Roost harassment is important over the entire winter, but even more so around mid-January when cormorant abundance is greatest and when cormorants are more focused on aquaculture ponds. The addition …

Cormorant Predation Of Commercial Catfish Aquaculture In The Mississippi Delta, Terrel Christie, Brian Dorr, Luke Roy, Anita M. Kelly, Carole Engle, Paul Burr, Brian Davis, Jonathan Van Senten

United States Department of Agriculture Wildlife Services: Staff Publications

Catfish aquaculture is an important agricultural commodity in Mississippi with most of the production. occurring in the Delta region of the state. A vital factor in managing these farms is reducing fish loss from bird depredation. The most notable bird species that consume catfish are Double-crested Cormorants. These migratory waterbirds arrive in fall and remain in the region throughout winter. Cormorant interactions with catfish aquaculture have previously been studied, but recent changes in the industry warrant collection of new data to understand the dynamic between catfish aquaculture and cormorants. The Southern Regional Aquaculture Center recently funded a study to estimate …

Predator Scent And Visual Cue Applied To Nest Boxes Fail To Dissuade European Starlings (Sturnus Vulgaris) From Nesting, Bradley Blackwell, Thomas W. Seamans, Morgan Pfeiffer, Bruce N. Buckingham

United States Department of Agriculture Wildlife Services: Staff Publications

Indirect predator cues have been shown to enhance perceived nest predation risk in both open-cup and cavity-nesting birds. We hypothesized that scent from the raccoon (Procyon lotor) inside nest boxes, supplemented with raccoon hair as a visual cue on the outside of the box, would enhance perceived risk to the European Starling (Sturnus vulgaris), resulting in reduced use of treated nest boxes and negative effects on reproduction. The starling is recognized, outside its native range, as a competitor with indigenous cavity nesters and a pest species, and efforts to deter its nesting have generally been unsuccessful. …

Factors And Costs Associated With Removal Of A Newly Established Population Of Invasive Wild Pigs In Northern U.S., Justin W. Fischer, Nathan P. Snow, Bradley E. Wilson, Scott F. Beckerman, Christopher N. Jacques, Eric H. Vannatta, Shannon L. Kay, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

The human-mediated spread of exotic and invasive species often leads to unintentional and harmful consequences. Invasive wild pigs (Sus scrofa) are one such species that have been repeatedly translocated throughout the United States and cause extensive damage to natural ecosystems, threatened and endangered species, agricultural resources, and private lands. In 2005, a newly established population of wild pigs was confirmed in Fulton County, Illinois, U.S. In 2011, a state-wide wild pig damage management program involving federal, state, and local government authorities directed a concerted effort to remove wild pigs from the county until the last wild pig (of 376 total) …

Effects Of Brodifacoum And Diphacinone Exposure On Four Species Of Reptiles: Tissue Residue Levels And Survivorship, Richard E. Mauldin, Gary W. Witmer, S. A. Shriner, Rachael S. Moulton, Katherine E. Horak

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Anticoagulant rodenticides are used worldwide to control pest rodent species. However, the risks posed to nontarget reptiles have not been well characterized. In this study, 46 giant ameivas (Ameiva ameiva), 39 boa constrictors (Boa constrictor), 33 wood turtles (Rhinoclemmys pulcherrima), and 47 green iguanas (Iguana iguana) were orally dosed with one of two levels of either diphacinone or brodifacoum anticoagulant in propylene glycol solutions. Dosages were derived using daily food intake (DFI) equations, converting DFI to an equivalent anticoagulant bait amount and gavaging the solution volume needed to deliver the quantity of anticoagulant in that amount of bait. Animals …

Multi-Isotopic (Δ2h, Δ13c, Δ15n) Tracing Of Molt Origin For European Starlings Associated With U.S. Dairies And Feedlots, Scott Werner, J. W. Fischer, Keith A. Hobson

United States Department of Agriculture Wildlife Services: Staff Publications

Introduced bird species can become invasive in agroecosystems and their management is inhibited if their origin and movements are not well understood. Stable isotope measurements of feathers can be used to infer molt origins and interstate movements in North America. We analyzed stable-hydrogen (δ²H), carbon (δ¹³C) and nitrogen (δ ¹⁵N) isotope ratios in feathers to better understand the molt origin of European starlings (Sturnus vulgaris) collected at dairies and feedlots throughout the United States. Primary feathers were used from 596 adult and 90 juvenile starlings collected during winter at dairies …

Conspecific Chemical Cues Facilitate Mate Trailing By Invasive Argentine Black And White Tegus, Shannon A. Richard, Isabella M. G. Bukovich, E. A. Tillman, Sanjiv Jayamohan, J. S. Humphrey, Paige E. Carrington, William E. Bruce, Bryan M. Kluever, Michael L. Avery, M. Rockwell Parker

United States Department of Agriculture Wildlife Services: Staff Publications

Squamate reptiles (snakes and lizards) rely on chemical cues from conspecifics to search the environment for potential mates. How such cues are used by invasive species to facilitate reproduction, especially seasonally, is a key question that can inform management practices. The Argentine black and white tegu (Salvator merianae) is an invasive reptile species in south Florida threatening native fauna in biodiverse regions such as Everglades National Park. While some information exists on the reproductive ecology of this species in its native range in South America, the chemical ecology of S. merianae is unclear especially in its invasive range. By testing …

Optimal Spatial Prioritization Of Control Resources For Elimination Of Invasive Species Under Demographic Uncertainty, Kim M. Pepin, Timothy J. Smyser, Amy J. Davis, Ryan S. Miller, Sophie Mckee, Kurt C. Vercauteren, William Kendall, Chris Slootmaker

United States Department of Agriculture Wildlife Services: Staff Publications

Populations of invasive species often spread heterogeneously across a landscape, consisting of local populations that cluster in space but are connected by dispersal. A fundamental dilemma for invasive species control is how to optimally allocate limited fiscal resources across local populations. Theoretical work based on perfect knowledge of demographic connectivity suggests that targeting local populations from which migrants originate (sources) can be optimal. However, demographic processes such as abundance and dispersal can be highly uncertain, and the relationship between local population density and damage costs (damage function) is rarely known. We used a metapopulation model to understand how budget and …

A Comparison Of Cost And Quality Of Three Methods For Estimating Density For Wild Pig (Sus Scrofa), Amy J. Davis, David A. Keiter, Elizabeth M. Kierepka, C. Slootmaker, Antoinette J. Piaggio, James C. Beasley, K. M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

A critical element in effective wildlife management is monitoring the status of wildlife populations; however, resources to monitor wildlife populations are typically limited. We compared cost effectiveness of three common population estimation methods (i.e. non-invasive DNA sampling, camera sampling, and sampling from trapping) by applying them to wild pigs (Sus scrofa) across three habitats in South Carolina, U.S.A where they are invasive. We used mark-recapture analyses for fecal DNA sampling data, spatially-explicit capture-recapture analyses for camera sampling data, and a removal analysis for removal sampling from trap data. Density estimates were similar across methods. Camera sampling was the least expensive, …

Technical Limitations Associated With Molecular Barcoding Of Arthropod Bloodmeals Taken From North American Deer Species, Erin M. Borland, Daniel A. Hartman, Matthew W. Hopken, Antoinette J. Piaggio, Rebekah C. Kading

United States Department of Agriculture Wildlife Services: Staff Publications

Accurate species-level identification of the source of arthropod bloodmeals is important for deciphering blood feeding patterns of field-collected specimens. Cytochrome c oxidase I (COI) mitochondrial gene sequencing has been used for this purpose; however, species resolution can be difficult to obtain from certain vertebrate genera, including Odocoileus. Sanger sequencing of mitochondrial genes was employed to identify the bloodmeal source of wild-caught mosquitoes trapped in Greeley, Colorado. Initial sequencing of the COI gene of mitochondrial DNA in bloodmeals was inadequate for species-level resolution of bloodmeals from deer in the genus Odocoileus, with current databases returning low fidelity matches to …

Additive And Non-Additive Responses Of Seedlings To Simulated Herbivory And Drought, Kasey Barton, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Drought is a global threat, increasing in severity and frequency throughout tropical ecosystems. Although plants often face drought in conjunction with biotic stressors, such as herbivory or disease, experimental studies infrequently test the simultaneous effects of drought and biotic stress. Because multiple simultaneous stressors may have non-additive and complex effects on plant performance, it is difficult to predict plant responses to multiple threats from research examining one stress at a time. Using an experimental approach in the greenhouse, we investigated potential non-additivity in seedling growth and survival to simulated drought and herbivory across a phylogenetically diverse pool of ten Hawaiian …

The Changing Triad Of Plague In Uganda: Invasive Black Rats (Rattus Rattus), Indigenous Small Mammals, And Their Fleas, Russell E. Enscore, Nackson Babi, Gerald Amatre, Linda Atiku, Rebecca J. Eisen, Kim M. Pepin, Rommelle Vera-Tudela, Christopher Sexton, Kenneth L. Gage

United States Department of Agriculture Wildlife Services: Staff Publications

Rattus rattus was first reported from the West Nile Region of Uganda in 1961, an event that preceded the appearance of the first documented human plague outbreak in 1970. We investigated how invasive R. rattus and native small mammal populations, as well as their fleas, have changed in recent decades. Over an 18-month period, a total of 2,959 small mammals were captured, sampled, and examined for fleas, resulting in the identification of 20 small mammal taxa that were hosts to 5,109 fleas (nine species). Over three-fourths (75.8%) of captured mammals belonged to four taxa: R. rattus, which predominated inside huts, …

Rnai: Applications In Vertebrate Pest Management, Katherine Horak

United States Department of Agriculture Wildlife Services: Staff Publications

Sequence-directed inhibition of protein synthesis by RNAi has potential as a means to control pest wildlife. Species specific by design, RNAi reduces impacts on nontarget species and the environment. Additional research advancing the field of RNAi-based management of vertebrate pest wildlife is timely.

Despite the potential diverse applications of RNAi technology in vertebrates (fertility control, invasive species eradication, and pest species control to protect human health and agriculture), little progress has been made in applying RNAi to these classes of animals. A single proof-of-concept study using RNAi to control sea lampreys combined with recent advances in RNAi delivery have opened …

Avian Influenza A Virus Associations In Wild, Terrestrial Mammals: A Review Of Potential Synanthropic Vectors To Poultry Facilities, J. Jeffrey Root, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

The potential role of wild mammals in the epidemiology of influenza A viruses (IAVs) at the farm-side level has gained increasing consideration over the past two decades. In some instances, select mammals may be more likely to visit riparian areas (both close and distant to farms) as well as poultry farms, as compared to traditional reservoir hosts, such as waterfowl. Of significance, many mammalian species can successfully replicate and shed multiple avian IAVs to high titers without prior virus adaptation and often can shed virus in greater quantities than synanthropic avian species. Within this review, we summarize and discuss the …

Improving The Accessibility And Transferability Of Machine Learning Algorithms For Identification Of Animals In Camera Trap Images: Mlwic2, Michael A. Tabak, Mohammad S. Norouzzadeh, David W. Wolfson, Erica J. Newton, Raoul K. Boughton, Jacob S. Ivan, Eric Odell, Eric S. Newkirk, Reesa Y. Conrey, Jennifer Stenglein, Fabiola Iannarilli, John Erb, Ryan K. Brook, Amy J. Davis, Jesse Lewis, Daniel P. Walsh, James C. Beasley, Kurt C. Vercauteren, Jeff Clune, Ryan S. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Motion-activated wildlife cameras (or “camera traps”) are frequently used to remotely and noninvasively observe animals. The vast number of images collected from camera trap projects has prompted some biologists to employ machine learning algorithms to automatically recognize species in these images, or at least filter-out images that do not contain animals. These approaches are often limited by model transferability, as a model trained to recognize species from one location might not work as well for the same species in different locations. Furthermore, these methods often require advanced computational skills, making them inaccessible to many biologists. We used 3 million camera …

Tissue Tropisms Of Avian Influenza A Viruses Affect Their Spillovers From Wild Birds To Pigs, Xiaojian Zhang, Fred L. Cunningham, Lei Li, Katie Hanson-Dorr, Liyuan Liu, Kaitlyn Waters, Minhui Guan, Alicia K. Olivier, Brandon S. Schmit, Jacqueline M. Nolting, Andrew S. Bowman, Mia Kim Torchetti, Thomas J. Deliberto, Xiu-Feng Wan

United States Department of Agriculture Wildlife Services: Staff Publications

Wild aquatic birds maintain a large, genetically diverse pool of influenza A viruses (IAVs), which can be transmitted to lower mammals and, ultimately, humans. Through phenotypic analyses of viral replication efficiency, only a small set of avian IAVs were found to replicate well in epithelial cells of the swine upper respiratory tract, and these viruses were shown to infect and cause virus shedding in pigs. Such a phenotypic trait of the viral replication efficiency appears to emerge randomly and is distributed among IAVs across multiple avian species and geographic and temporal orders. It is not determined by receptor binding preference …