Digital Commons Network^™

Stress-Induced Changes In Abundance Differ Among Obligate And Facultative Endosymbionts Of The Soybean Aphid, Laramy S. Enders, Nicholas Miller

Department of Entomology: Faculty Publications

Bacterial endosymbionts can drive evolutionary novelty by conferring adaptive benefits under adverse environmental conditions. Among aphid species there is growing evidence that symbionts influence tolerance to various forms of stress. However, the extent to which stress inflicted on the aphid host has cascading effects on symbiont community dynamics remains poorly understood. Here we simultaneously quantified the effect of host-plant induced and xenobiotic stress on soybean aphid (Aphis glycines) fitness and relative abundance of its three bacterial symbionts. Exposure to soybean defensive stress (Rag1 gene) and a neurotoxic insecticide (thiamethoxam) substantially reduced aphid composite fitness (survival 9 reproduction) …

Composition And Diversity Of Avian Communities Using A New Urban Habitat: Green Roofs, Brian E. Washburn, Ryan M. Swearingin, Craig K. Pullins, Matthew E. Rice

United States Department of Agriculture Wildlife Services: Staff Publications

Green roofs on buildings are becoming popular and represent a new component of the urban landscape. Public benefits of green roof projects include reduced stormwater runoff, improved air quality, reduced urban heat island effects, and aesthetic values. As part of a city-wide plan, several green roofs have been constructed at Chicago’s O’Hare International Airport (ORD). Like some other landscaping features, green roofs on or near an airport might attract wildlife and thus increase the risk of bird–aircraft collisions. During 2007–2011, we conducted a series of studies to evaluate wildlife use of newly constructed green roofs and traditional (gravel) roofs on …

Nutritional Effects On Reproductive Performance Of Captiveadult Female Coyotes (Canis Latrans), Eric M. Gese, Beth M. Roberts, Frederick F. Knowlton

United States Department of Agriculture Wildlife Services: Staff Publications

Interactions between animals and their environment are fundamental to ecological research. Field studies of coyote (Canis latrans) reproductive performance suggest mean litter size changes in response to prey abundance. However, this relationship has been assessed primarily by using carcasses collected from trappers. The objective of this study was to assess whether nutritional manipulation prior to mating affected reproduction in adult female coyotes. We examined the effects of caloric restriction during the 7 months prior to estrus on the reproductive rates of 11 captive female coyotes and the subsequent initial survival of pups through two reproductive cycles. This was …

Limited Transmission Of Emergent H7n9 Influenza A Virus In A Simulated Live Animal Market: Do Chickens Pose The Principal Transmission Threat?, Angela Bosco-Lauth, Richard A. Bowen, J. Jeffrey Root

United States Department of Agriculture Wildlife Services: Staff Publications

Emergent H7N9 influenza A virus has caused multiple public health and financial hardships. While some epidemiological studies have recognized infected chickens as an important bridge for human infections, the generality of this observation, the minimum infectious dose, and the shedding potential of chickens have received conflicting results. We experimentally tested the ability of domestic chickens (Gallus gallus domesticus) to transmit H7N9 to co-housed chickens and to several other animal species in an experimental live animal market. Results indicated that an infected chicken failed to initiate viral shedding of H7N9 to naIve co-housed chickens. The infected chicken did, however, …

Quantifying The Adaptive Cycle, David G. Angeler, Craig R. Allen, Ahjond S. Garmestani, Lance H. Gunderson, Olle Hjerne, Monika Winder

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term …

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 …

Remembering Paul B. Kannowski, Robert Seabloom

The Prairie Naturalist

I am saddened to report that Dr. Paul Kannowski passed away 3 September 2015, succumbing to cancer. He was 88. A native of Grand Forks, Paul attended the University of North Dakota for his B.S. and M.S. degrees, and the University of Michigan for his Ph.D. He joined the University of North Dakota Biology Department in 1957, retiring in 1990 after 33 years of service

Paul chaired UND’s Biology Department twice, totaling 13 years, considered to be a remarkable achievement by many of us who have been exposed to that task! His leadership was instrumental in the nearly exponential growth …

Prevalence Of Tick-Borne Pathogens In Small Mammals And White-Tailed Deer In Southeast Nebraska, Tim M. Hotaling

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The prevalence of tick-borne diseases has been increasing in the United States for the past couple decades. Studies have been conducted throughout the US identifying tick-borne disease pathogens as well as their hosts and prevalence. Research was conducted in Nebraska to determine the presence of some tick-borne disease pathogens, their vectors, and their hosts, with emphasis made on Borrelia spp., Rickettsia rickettsii, and Ehrlichia chaffeensis.

Small rodents in southeast Nebraska were trapped and sampled at eight study sites using live capture traps. Captured rodents were assessed for active parasitism by ticks which were collected and placed in alcohol. …

Switchgrass Germplasm Resources, Michael D. Casler, Kenneth P. Vogel, Melanie Harrison

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) is an important native grass and dominant member of the tallgrass prairie ecosystem. It is used for conservation, restoration, livestock feed production, and bioenergy feedstock production. The purpose of this review is to describe the biological and geographical basis for switchgrass germplasm diversity and to provide a resource for scientists and outreach personnel to find switchgrass germplasm to meet their needs. Upland and lowland ecotypes represent the most important polymorphism in switchgrass, with distinct but overlapping geographic distributions. Variation in ploidy exists within both ecotypes, with 2n = 4x = 36 the dominant ploidy …

Discovery And Delimitation: Criconematid Nematodes Of North American Grasslands, Magdalena Jean Olson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Approximately 200 years ago, North American landscapes were dominated by vast expanses of grassland. The Great Plains, an ecologically complex and diverse ecoregion, extended from Canada to the Gulf of Mexico, and from the Rocky Mountains to the border of the eastern hardwood forest in Indiana. Now the original tallgrass prairie exists in small widely dispersed remnant patches surrounded by agroecosystems. This study is an effort to characterize soil nematode diversity and population structure within those remnant patches. The plant parasitic nematode family Criconematidae serves as our indicator for nematode diversity, due to its global distribution, high abundance in natural …

Cryptic Speciation In The Acari: A Function Of Species Lifestyles Or Our Ability To Separate Species?, Anna Skoracka, Sara Magalhães, Brian G. Rector, Lechosław Kuczyński

Harold W. Manter Laboratory of Parasitology: Library Materials

There are approximately 55,000 described Acari species, accounting for almost half of all known Arachnida species, but total estimated Acari diversity is reckoned to be far greater. One important source of currently hidden Acari diversity is cryptic speciation, which poses challenges to taxonomists documenting biodiversity assessment as well as to researchers in medicine and agriculture. In this review, we revisit the subject of biodiversity in the Acari and investigate what is currently known about cryptic species within this group. Based on a thorough literature search, we show that the probability of occurrence of cryptic species is mainly related to the …

Socio-Economic Instability And The Scaling Of Energy Use With Population Size, John P. Delong, Oskar Burger

School of Biological Sciences: Faculty Publications

The size of the human population is relevant to the development of a sustainable world, yet the forces setting growth or declines in the human population are poorly understood. Generally, population growth rates depend on whether new individuals compete for the same energy (leading to Malthusian or density-dependent growth) or help to generate new energy (leading to exponential and super-exponential growth). It has been hypothesized that exponential and super-exponential growth in humans has resulted from carrying capacity, which is in part determined by energy availability, keeping pace with or exceeding the rate of population growth. We evaluated the relationship between …

Swift Fox Abundance Along The Heartland Expressway Corridor In Nebraska, Marc Albrecht

Nebraska Department of Transportation: Research Reports

No abstract provided.

Hydrologic Mediation Of The Spatial And Temporal Variability Of The Soil Carbon Dioxide Stable Isotopic Composition Of A Subalpine Watershed, Theresa Marie Lorenzo

School of Natural Resources: Dissertations, Theses, and Student Research

The stable carbon isotopic composition of CO₂ (δ¹³C-CO₂) has been studied as an indicator of changes in ecosystem CO₂ exchange. Soil moisture is an important factor in ecosystem CO₂ exchange through its influence on physiological and soil physical processes. However, the majority of previous research analyzing the influence of soil moisture on soil and soil-respired δ¹³C-CO₂ has been conducted with limited consideration of topographical variation, which controls the distribution of soil moisture across a landscape. This study characterized the stable isotopic composition (δ¹³C) and concentrations of soil CO …

Acute Toxicity Of Β-N-Methylamino-L-Alanine (Bmaa) To Fathead Minnow (Pimephales Promelas) And Zebrafish (Danio Rerio), Jiayi Wang

School of Natural Resources: Dissertations, Theses, and Student Research

β-N-methylamino-L-alanine (BMAA) is a neurotoxic amino acid produced by most species of cyanobacteria. Exposure to BMAA has been hypothesized as a cause of ALS and possibly Parkinson’s and Alzheimer’s diseases for several decades. Both in vitro and in vivo experiments revealed that exposure to elevated concentrations of BMAA can damage motor neurons and cause motor dysfunctions. However, the exact mechanism of BMAA-induced neurotoxicity has not been well understood.

Based on the available literature and in spite of its water-soluble and non-protein nature, BMAA appears to be able to bioaccumulate in organisms. The ubiquity of cyanobacteria and the potential for bioaccumulation …

The Status Of Fishes In The Missouri River, Nebraska: Blue Sucker Cycleptus Elongatus, Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Blue Sucker Cycleptus elongatus are a large-bodied, benthic fish that are considered an indicator species for riverine health. A combination of historic commercial fishing and anthropogenic modifications to riverine habitat led to blue suckers being listed as a candidate species for the federal threatened or endangered species list in 1993. However, they were never designated a federally protected species. Locally, Blue Suckers are currently listed as a Nebraska Natural Legacy Project’s Tier 1 species but population changes and trends have not been quantified. Therefore, the objective of this paper was to evaluate the current population status of Blue Sucker in …

Development Modeling Of Lucilia Sericata (Diptera: Calliphoridae), Amanda Roe, Leon G. Higley

School of Natural Resources: Faculty Publications

The relationship between insect development and temperature has been well established and has a wide range of uses, including the use of blow flies for postmortem (PMI) interval estimations in death investigations. To use insects in estimating PMI, we must be able to determine the insect age at the time of discovery and backtrack to time of oviposition. Unfortunately, existing development models of forensically important insects are only linear approximations and do not take into account the curvilinear properties experienced at extreme temperatures. A series of experiments were conducted with Lucilia sericata, a forensically important blow fly species, that met …

The Uncertain Climate Footprint Of Wetlands Under Human Pressure, Ana Maria Roxana Petrescu, Annalea Lohila, Juha-Pekka Tuovinen, Dennis D. Baldocchi, Ankur R. Desai, Nigel T. Roulet, Timo Vesala, Albertus Johannes Dolman, Walter C. Oechel, Barbara Marcolla, Thomas Friborg, Janne Rinne, Jaclyn Hatala Matthes, Lutz Merbold, Ana Meijide, Gerard Kiely, Matteo Sottocornola, Torsten Sachs, Donatella Zona, Andrej Varlagin, Derrick Y.F. Lai, Elmar Veenendaal, Frans-Jan W. Parmentier, Ute Skiba, Magnus Land, Arjan Hensen, Jacobus Van Huissteden, Lawrence B. Flanagan, Narasinha J. Shurpali, Thomas Grünwald, Elyn R. Humphreys, Marcin Jackowicz-Korczynski, Mika A. Aurela, Tuomas Laurila, Carsten Grüning, Chiara A.R. Corradi, Arina P. Schrier-Uijl, Torben R. Christensen, Mikkel P. Tamstorf, Mikhail Mastepanov, Pertti J. Martikainen, Shashi Verma, Christian Bernhofer, Alessandro Cescatti

School of Natural Resources: Faculty Publications

Significant climate risks are associated with a positive carbon–temperature feedback in northern latitude carbon-rich ecosystems,making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and quasi-continuous ecosystem observations of CO₂ and CH₄ fluxes. Experimental areas are located both in natural and in managed wetlands and cover a wide range of climatic regions, ecosystem types, and management practices. Based on direct observations we predict that sustained CH₄ emissions in natural ecosystems are …

Timing Of Spring Surveys For Midcontinent Sandhill Cranes, Aaron T. Pearse, Gary L. Krapu, David A. Brandt, Glen A. Sargeant

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The U.S. Fish and Wildlife Service has used spring aerial surveys to estimate numbers of migrating sandhill cranes (Grus canadensis) staging in the Platte River Valley of Nebraska, USA. Resulting estimates index the abundance of the midcontinent sandhill crane population and inform harvest management decisions. However, annual changes in the index have exceeded biologically plausible changes in population size (>50% of surveys between 1982 and 2013 indicate >20% change), raising questions about nuisance variation due to factors such as migration chronology. We used locations of cranes marked with very-highfrequency transmitters to estimate migration chronology (i.e., proportions of …

Investing In Prospective Cohorts For Etiologic Study Of Occupational Exposures, A Blair, C J. Hines, K W. Thomas, Mcr Alavaja, L E. Beane Freeman, J A. Hoppin, F Kamel, C F. Lynch, J H. Lubin, D T. Sliverman, E Whelan, S H. Zahm, D P. Sandler

United States Environmental Protection Agency: Publications

Prospective cohorts have played a major role in understanding the contribution of diet, physical activity,medical conditions, and genes to the development ofmany diseases, but have not been widely used for occupational exposures. Studies in agriculture are an exception. We draw upon ourexperience using this design to study agriculturalworkers to identify conditions that might foster use of prospective cohorts to study other occupational settings. Prospective cohort studies are perceived by many as the strongest epidemiologic design. It allows updating of information on exposure and other factors, collection of biologic samples before disease diagnosis for biomarker studies, assessment of effect modification by …

Estimating Relative Sea-Level Rise And Submergence Potential At A Coastal Wetland, Donald R. Cahoon

United States Geological Survey: Staff Publications

A tide gauge records a combined signal of the vertical change (positive or negative) in the level of both the sea and the land to which the gauge is affixed; or relative sealevel change, which is typically referred to as relative sea-level rise (RSLR). Complicating this situation, coastal wetlands exhibit dynamic surface elevation change (both positive and negative), as revealed by surface elevation table (SET) measurements, that is not recorded at tide gauges. Because the usefulness of RSLR is in the ability to tie the change in sea level to the local topography, it is important that RSLR be calculated …

Masked Expression Of Life- History Traits In A Highly Variable Environment, Jason A. Deboer, Joseph J. Fontaine, Christopher J. Chizinski, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Differing life-history strategies may act as a constraint on reproductive expression that ultimately limits the ability of individual species to respond to changes in the magnitude or frequency of environmental variation, and potentially underlies the variation oft en inherent in phenotypic and evolved responses to anthropogenic change. Alternatively, if there are environmental cues that predict reproductive potential, differential expression of life-history strategies may represent differences in the adaptive capacity to optimize current reproductive value given variation in environmental conditions. We compared several aspects of walleye Sander vitreus spawning ecology at two reservoirs that diff er in environmental variability (i.e., annual …

Educating Pastoralists And Extension Officers On Diverse Livestock Diseases In A Changing Environment In Tanzania, Christopher Gustafson, Elizabeth Vanwormer, Rudovick Kazwala, Asha Makweta, Goodluck Paul, Woutrina Smith, Jonna A. K. Mazet

Department of Agricultural Economics: Faculty Publications

East African pastoralists and their livestock are vulnerable to alterations in resource availability and disease transmission and frequently face poor access to livestock health services. Government veterinarians tasked with guiding health services must prioritize livestock health risks and allocate limited resources across disparate ecosystems with different disease threats. To identify livestock diseases of concern and strategies for improving herd health and resilience, we conducted community focus groups with pastoralists and interviewed pastoralist household leaders, village extension officers, and government veterinary officials in south-central Tanzania, an area experiencing rapid population growth and environmental change. All participants discussed pastoralist access to livestock …

Population-Based Trends In High-Grade Cervical Lesions In The Early Human Papillomavirus Vaccine Era In The United States, Susan Hariri, Michelle L. Johnson, Nancy M. Bennett, Heidi M. Bauer, Ina U. Park, Sean Schafer, Linda M. Niccolai, Elizabeth R. Unger, Lauri E. Markowitz

United States Public Health Resources

BACKGROUND: Cervical intraepithelial neoplasia grade 2, 3, and adenocarcinoma in situ (CIN2+) lesions can be monitored as early indicators of human papillomavirus (HPV) vaccine impact. Changes to screening utilization will affect observed reductions in CIN2+ rates and complicate the interpretation of vaccine impact. METHODS: From 2008 to 2012, 9119 cases of CIN2+ among 18- to 39-year-old residents of catchment areas in California, Connecticut, New York, and Oregon were reported to the HPV-IMPACT Project, a sentinel system for monitoring the population impact of HPV vaccine. Age-stratified CIN2+ incidence rates were calculated for each catchment.

Annual cervical screening was estimated for California, …

The Beetles Of The Lesser Antilles (Insecta, Coleoptera): Diversity And Distributions, Stewart B. Peck

Insecta Mundi

The island arc of the Lesser Antilles lies at the eastern margin of the Caribbean Sea in the Western Hemisphere, and stretches from the eastern end of the islands of the Greater Antilles (at the Virgin Islands), south to a position near the continental islands of Trinidad and Tobago at the north eastern corner of South America. The islands are a part of the West Indian Islands biodiversity “hotspot” and have been available for terrestrial colonization for about the past 15 million years. This is a status report on present knowledge of the beetle faunas of these islands, which is …

Sea Level And Turbidity Controls On Mangrove Soil Surface Elevation Change, Catherine E. Lovelock, Maria Fernanda Adame, Vicki Bennion, Matthew Hayes, Ruth Reef, Nadia Santini, Donald R. Cahoon

United States Geological Survey: Staff Publications

Increases in sea level are a threat to seaward fringing mangrove forests if levels of inundation exceed the physiological tolerance of the trees; however, tidal wetlands can keep pace with sea level rise if soil surface elevations can increase at the same pace as sea level rise. Sediment accretion on the soil surface and belowground production of roots are proposed to increase with increasing sea level, enabling intertidal habitats to maintain their position relative to mean sea level, but there are few tests of these predictions in mangrove forests. Here we used variation in sea level and the availability of …

Shorebird Migration In The Face Of Climate Change, Ryan J. Stutzman, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Changes in temperature and seasonality resulting from climate change are heterogeneous, potentially altering important sources of natural selection acting on species phenology. Some species have apparently adapted to climate change but the ability of most species to adapt remains unknown. The life history strategies of migratory animals are dictated by seasonal factors, which makes these species particularly vulnerable to heterogeneous changes in climate and phenology. Here, we examine the phenology of migratory shorebirds, their habitats, and primary food resources, and we hypothesize how climate change may affect migrants through predicted changes in phenology. Daily abundance of shorebirds at stopover sites …

Quantifying The Adaptive Cycle, David G. Angeler, Craig R. Allen, Ahjond S. Garmestani, Lance H. Gunderson

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term …

Antibody Response Of Cattle To Vaccination With Commercial Modified Live Rabies Vaccines In Guatemala, Amy T. Gilbert, Lauren Greenberg, David Moran, Marlon Alvarado, Daniel L. Garcia, Leonard Peruski

United States Department of Agriculture Wildlife Services: Staff Publications

Vampire bat rabies is a public and animal health concern throughout Latin America. As part of an ecological study of vampire bat depredation on cattle in southern Guatemala,we conducted a vaccine seroconversion study among three dairy farms. The main objectives of this cross sectional and cohort study were to understand factors associated withbat bites among cattle, to determine whether unvaccinated cattle had evidence of rabies virus exposure and evaluate whether exposure was related to bat bite prevalence, and to assess whether cattle demonstrate adequate seroconversion to two commercial vaccines used in Guatemala. In 2012, baseline blood samples were collected immediately …

Short-Horned Grasshopper Subfamilies Feed At Different Rates On Big Bluestem And Switchgrass Cultivars, Muhammad Ullah, Fatima Mustafa, William W. Hoback, Mathew L. Brust, Kerri M. Farnsworth-Hoback, John E. Foster

Department of Entomology: Faculty Publications

Grasshopper species belonging to subfamilies Melanoplinae, Gomphocerinae and Oedipodinae were tested for their feeding rate on three types of grass. All grasshopper species were offered Shawnee and Kanlow cultivars of switchgrass, Panicum virgatum L. and big bluestem, Andropogon gerardii Vitman. The grasshoppers, Melanoplus femurrubrum and Melanoplus differentialis were also tested for their feeding on turgid or wilted leaves of the Shawnee cultivar of switchgrass. We found that M. differentialis consumed more switchgrass compared to big bluestem while M. femurrubrum and Arphia xanthoptera consumed the most Shawnee switchgrass. The M. differentialis consumed more turgid grass compared to wilted switchgrass. The feeding …