Digital Commons Network^™

Understanding How Changes In Precipitation Intensity Will Affect Vegetation In The Western U.S., Cristina Chirvasa

Fall Student Research Symposium 2021

Precipitation events are becoming more intense as the atmosphere warms, but it remains unclear how precipitation intensification will affect plant growth in arid and semiarid ecosystems. There is conflicting evidence suggesting that larger precipitation events may either increase or decrease plant growth. Here, we report the growth responses of herbaceous and woody plants to experimental manipulations of precipitation intensity in a cold, semi-arid ecosystem in Utah, USA. In this experiment, precipitation was collected and redeposited as fewer, larger events with total annual precipitation kept constant across treatments. Results from the first two growing seasons revealed that more intense events ‘pushed’ …

Estimating Cattle Density Using Wildlife Cameras, Emily Bonebrake

Fall Student Research Symposium 2021

Quantifying the abundance and distribution of animal populations is critical for effective wildlife research and management. Due to their cost-effectiveness, wildlife cameras have become an increasingly popular tool for estimating population densities. Previously, this technique relied on ‘capture-recapture’ models that utilized re-sightings of individually marked animals, but in recent years methods have been developed to estimate the population densities of unmarked animals. One such method is the random encounter and staying time (REST) technique, which does this by assuming that the cumulative time animals stay within the view of the camera scales linearly with the number of individuals. This allows …

Spatiotemporal Variation Of An Eastern Tropical Pacific Pelagic Community Assessed With Free-Drifting Bruvs, Tyler Stephen Plum

All HCAS Student Capstones, Theses, and Dissertations

Information about pelagic community diversity and ecology generally lags far behind that of coastal communities, and largely derives from fisheries data that do not reflect small and non-target species. We describe spatiotemporal vertebrate species diversity and variability over a 3,486 km² area of highly productive pelagic marine ecosystem in Pacific Panama using drifting baited remote underwater video stations (BRUVS), a non-invasive fishery-independent sampling technique. We observed 26 taxa from 17 families, including 1 mammal, 3 reptile, 5 elasmobranch, and 17 teleost species. Community assemblages differed on and off the continental shelf and between wet (April – December) and dry …

An Assessment Of The Diverse Freshwater Turtle Fauna Of Mississippi, Lucas Haralson

Master's Theses

Nestled within the Southeastern United States Turtle Priority Area, Mississippi boasts impressive freshwater turtle diversity and is home to 8.6% of extant turtle species. Despite this impressive richness, few studies have assessed freshwater turtle assemblages in this hotspot of aquatic diversity. This research aimed to elucidate the distributions and abundances of freshwater turtle species through a statewide investigation of all major river drainages of the state. Using baited hoop nets (90 cm and 120 cm diameter), turtles were collected, identified to species and sex, and measured, before being released. Turtle assemblages were assessed in both lotic and lentic environments from …

Closely Related Gull Species Show Contrasting Foraging Strategies In An Urban Environment, K. A. Lato, D. J. Madigan, R. R. Veit, L. H. Thorne

Publications and Research

The expansion of urban landscapes has both negative and positive effects on wildlife. Understanding how different species respond to urbanization is key to assessing how urban landscapes influence regional wildlife behavior and ecosystem structure. Gulls are often described as strong urban adapters, but few studies have explored species-specific differences in habitat use. Here, we use GPS tracking in conjunction with stable isotope analysis (SIA) to quantify the habitat use and trophic ecology of great black-backed gulls (Larus marinus) and herring gulls (L. argentatus) in an urbanized area. Non-Metric Multidimensional Scaling (NMDS) of foraging locations revealed significant differences in the habitat …

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

Theses and Dissertations

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

Soil Microbial Community Dynamics In Response To Prescribed Extreme Fires Following Juniperus Virginiana Invasion In The Loess Canyons Of Nebraska, Julie A. Fowler

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

In Nebraska and other regions of the Great Plains, the conifer Juniperus virginiana (eastern redcedar) is converting grasslands to dense woodlands. This is driven by the interacting drivers of fire suppression, altered grazing regimes, climate change and other anthropogenic factors, impacting the provisioning of ecosystem services. This vegetation state transition modifies water resource regulation and biogeochemical cycles leading to altered edaphic properties including soil microbial community composition. To restore these grasslands and control J. virginiana spread, prescribed extreme burns are implemented as a management tool through local prescribed burn associations. We hypothesized that the alternative state transition to dense J. …

Uncoupled Seasonal Variability Of Transparent Exopolymer And Coomassie Stainable Particles In Coastal Mediterranean Waters: Insights Into Sources And Driving Mechanisms, Marina Zamanillo, Eva Ortega-Retuerta, Carolina Cisternas-Novoa, Cèlia Marrasé, Carles Pelejero, Josep Pascual, Josep M. Gasol, Anja Engel, Rafel Simó

Research outputs 2014 to 2021

Transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP) are gel-like particles, ubiquitous in the ocean, that affect important biogeochemical processes including organic carbon cycling by planktonic food webs. Despite much research on both groups of particles (especially TEP) over many years, whether they exist as distinctly stainable fractions of the same particles or as independent particles, each with different driving factors, remains unclear. To address this question, we examined the temporal dynamics of TEP and CSP over 2 complete seasonal cycles at 2 coastal sites in the Northwestern Mediterranean Sea, the Blanes Bay Microbial Observatory (BBMO) and the L’Estartit …

A New Species Of Vaejovis From The Mule Mountains Above Bisbee, Arizona (Scorpiones: Vaejovidae), Brandon T. Myers, Richard F. Ayrey

Euscorpius

No abstract provided.

Towards A More Comprehensive Understanding Of Wild Pig (Sus Scrofa) Impacts On Agricultural Producers: Insights From A Texas Case Study, Keith M. Carlisle, Nicole Didero, Sophie Mckee, Julie Elser, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

This research investigates the impacts of invasive wild pigs (Sus scrofa Linneaus) on agricultural producers in Texas, with the aim of identifying and describing all categories of wild pig impacts and quantifying the extent of producers’ over- or underestimation of their total wild pig-related costs in 2018, as compared to calculations based upon data subsequently provided by the producers about individual wild pig-related costs and losses. Based on interviews with 23 producers in 16 Texas counties, we identified more than 20 discrete categories of negative impacts and negligible positive impacts associated with wild pigs. Among them were categories that have …

Habitat Assessment Of Ozark Glades Using Selected Epigeal Predatory Arthropods, Austin Key Jones

Graduate Theses and Dissertations

Epigeal predatory arthropods were collected with pitfall-style traps in nine sandstone glades of varying ecological stages, and management histories, in the Ozarks of Northern Arkansas over three years. These sites were categorized into three Site Types; Intact, high quality glades; Degraded, forest-encroached glades, and Restored glades which had received woody vegetation removal and burning. Collections of ground spiders (Gnaphosidae), predatory ground beetles (Carabidae), and the sole species of scorpion present in the Ozarks, Centruroides vittatus, were reported on as well as the applicability of arthropod collection methods for glade habitat assessment. Habitat characteristics were recorded for each site and analyzed …

Implications Of Condition Shifts On Shallow Lakes, Alicia Skolte

Biology Graduate Theses

Shallow lakes have undergone condition shifts throughout time by natural causes, management actions, or a combination of the two. Because shallow lakes are especially vulnerable to shifts towards turbid conditions, management actions on shallow lakes have focused on water level/retainment, biomanipulations, the management/removal of non-native species, and land-use changes. This review compiles a summary on ecosystem shifts including a discussion on the frequency of shifts historically and the importance and causes of those shifts, trophic cascades, and the influence of introduced species in shallow lakes. This review will then examine case-studies of management-linked shifts and explain current shift theory. Next, …

Feeding Patterns And Diet Overlap Of Muskellunge And Co-Occurring Piscivores In Minnesota Lakes, Kamden Glade

Biology Graduate Theses

Muskellunge Esox masquinongy are the largest member of the family Esocidae found in Minnesota and are managed for trophy angling opportunities with large minimum size requirements, limited harvest, and stocking to support existing populations or expand angling opportunities. While Muskellunge impacts at the community level appear minimal based on available literature, relatively little is known about Muskellunge diets, eat the le particularly in Minnesota. In this study, we used gastric lavage to examine gut contents of Muskellunge, Northern Pike Esox lucius, Walleye Sander vitreus, and Largemouth Bass Micropterus salmoides. Diets were quantified using an index of relative importance (IRI) and …

Boxed In: Hinge Closing Performance Of Ornate Box Turtles (Terrapene Ornata), Gina L. Buelow

Graduate Theses/Dissertations

Turtles are perhaps best known for the bony shells that encase them, a unique morphological trait that provides protection against predators. Many taxa have even evolved the ability to enclose themselves using hinges that can be used to create a seal between the carapace and plastron. I measured the hinge closing force of Ornate Box Turtles (Terrapene ornata) to assess the performance of this unusual yet ecologically important trait. I sampled head-started turtles from Thomson Sand Prairie in the Upper Mississippi River National Wildlife and Fish Refuge and wild turtles collected in northern Oklahoma. To assess the effects of head-starting …

Index To Volume 89

Nebraska Bird Review

Adams, Marie 52

to

Zonotrichia leucophrys gambelii 168 leucophrys 75, 168-169 oriantha 75, 169

Review Of The Sandhill Crane State: A Naturalist’S Guide To Nebraska By Paul Johnsgard, Ruth Stearns

Nebraska Bird Review

Dr. Paul Austin Johnsgard left us one last gift, in this reference guide to all places natural in Nebraska. Published posthumously, and available for purchase or free via UNL’s Digital Commons, this book arrived at my doorstep like a veritable “seed catalog” of Nebraska’s places of wonder to delight and inspire fair weather adventures just before the long winter set in. He wants us to explore the state as he had done, to be excited by all the out-ofdoors Nebraska has to offer.

Northern Saw-Whet Owl Autumn Migration In Eastern Nebraska: Results From A Three-Year Banding Study, Stephen J. Brenner, Joel G. Jorgensen

Nebraska Bird Review

Prior to 2019, records of NSWOs in Nebraska during fall were limited. There were fewer than five accepted reports in eastern Nebraska since the 1950s (Silcock and Jorgensen, 2021). The Hitchcock banding station along the Missouri River bluffs in nearby western Iowa has captured, banded, and released 20-50 birds during autumn migration for a number of years (J. Toll, personal communication). Furthermore, a single season banding study in central Nebraska during fall 2004 captured 14 NSWOs (Kim 2005), suggesting the species may migrate annually over much of the state in fall, or at least in more years than previously thought. …

Review Of Nest Records Of Nebraska Birds By Wayne J. Mollhoff, W. Ross Silcock

Nebraska Bird Review

This book summarizes a lifetime of investigation of Nebraska’s breeding birds by Wayne Mollhoff. Even though I say the book summarizes a lifetime of investigation, I would not be surprised if Wayne resurfaces in a few years with a follow-up of some sort, intrepid investigator that he is. Over the years Wayne has spent innumerable days in the field climbing trees in full forestry gear, wading and kayaking marshes and rivers, hiking over prairies, and bushwhacking through dense forests (there are still a few in Nebraska). But this isn’t the totality of Wayne’s talents; he is a determined researcher with …

The Nebraska Bird Review, Volume 89 Number 4, December 2021

Nebraska Bird Review

Fall Field Report, August - November 2021 by W. Ross Silcock

Book Review: Nest Records of Nebraska Birds by Wayne J. Mollhoff Reviewed by W. Ross Silcock

Northern Saw-whet Owl Autumn Migration in Eastern Nebraska: Results from a Three-year Banding Study by Stephen J. Brenner and Joel G. Jorgensen

Mute Swan Observation at Gavins Point Dam Area, Cedar/Knox Co., Nebraska by Caleb Strand and Mark A. Brogie

Book Review: The Sandhill Crane State: A Naturalist's Guide to Nebraska by Paul Johnsgard, Reviewed by Ruth Stearns

Index to Volume 89

Subscription and Organization Information

Mute Swan Observation At Gavins Point Dam Area, Cedar/Knox Co., Nebraska, Caleb Strand, Mark A. Brogie

Nebraska Bird Review

The Nebraska Ornithologists’ Union Records Committee (NOURC) considers Mute Swan (Cygnus olor) to be Accidental in Nebraska (NOURC 2017) with only two accepted records. A review of Mute Swan status in the Midwest and Nebraska, how individual records in Nebraska are evaluated to determine wild provenance, and a review of Nebraska reports can be found in “The Mute Swan in Nebraska: History and Current Status” (Brogie et al. 2016).

The following is an account of the third NOURC accepted record for Mute Swan in Nebraska. On 11 June 2021 we observed two sub-adult Mute Swans on Lake Yankton, Cedar County, …

Fall Field Report, August-November 2021, W. Ross Silcock

Nebraska Bird Review

INTRODUCTION Recent years have seen increasing reports of birds lingering quite late, and this fall was no exception. Notable groups exhibiting tardy departures were shorebirds and vireos. Tardy shorebirds were record late Solitary Sandpipers, near-record late Dunlin, and late Long-billed Curlew, Ruddy Turnstone, Least and Semipalmated Sandpipers, Long-billed Dowitcher, and Wilson’s Phalarope. Among the vireos, all regular species were at least tardy; record late was a Red-eyed Vireo, a Warbling Vireo was record late for the Panhandle, and a Blue-headed Vireo was second latest on record. Record late was a Barn Swallow, and a Mountain Bluebird was record late in …

Reproductive Success Of Captive-Reared Allegheny Woodrats (Neotoma Magister) Released Into Genetically Depauperate Populations, Miracle M. Davis, Timothy J. Smyser, Scott A. Johnson, Joseph Duchamp, Jeffery L. Larkin, Robert K. Swihart, Jacqueline M. Doyle

United States Department of Agriculture Wildlife Services: Staff Publications

Habitat fragmentation and degradation have led to a proliferation of small and isolated populations that are vulnerable to genetic erosion. Reduction in habitat and concomitant declines in population connectivity can expediate the collapse of species that exist as natural metapopulations. In recent years, Allegheny woodrats (Neotoma magister) have experienced local extirpations and declines in genetic diversity across their range due to disease-related mortality, reduced food availability, and disruption of connectivity among subpopulations. In response, we developed a captive-breeding program to facilitate genetic management of isolated woodrat populations in Indiana. Between 2010 and 2012, 27 captive-reared individuals were released to four …

Natural Regeneration Dynamics And Survival Influenced By Abiotic And Biotic Factors In A Bottomland Hardwood Forest, Lydia J. Voth Rurup

Electronic Theses and Dissertations

Riparian ecosystems are vital to the landscape, providing critical services including water filtration and purification, flood and erosion control, carbon sequestration, biodiversity support, and aesthetic value. Bottomland hardwood forests, however, are threatened by invasive species, land loss/conversion, inconsistent or absence of harvesting disturbances, and altered hydrological patterns, leading to reduced success of desired, native species. This research assessed regeneration dynamics and one-year survival in a seasonally-flooded bottomland hardwood forest at Boggy Slough Conservation Area in East Texas to identify abiotic and biotic factors important for successful establishment of native regeneration. Areas sampled included two that were previously treated with herbicide …

Comprehensive Study Of Human Pathogenic Trypanosomatids: From Chemotherapies To Disease Ecology, Felipe Rodriguez

Open Access Theses & Dissertations

The vector-borne diseases Leishmaniasis and Chagas disease, caused by the kinetoplastid parasites Leishmania spp. and Trypanosoma cruzi respectively, are among the most important parasitic diseases in the group of neglected tropical diseases. Even though the two diseases are endemic to the Americas, they affect millions of people worldwide. Leishmaniasis and Chagas disease cause a great array of symptoms and some of them can be fatal if left undiagnosed and untreated. Current treatment regimens are becoming less effective, vaccines are still not available, and diagnosis needs to be improved. Vector control has been responsible for a decrease of diseases in endemic …

Organizational Networking, Leadership, And Community Engagement: A Case Study Of The Revitalization Of An Impaired Watershed In Richmond, Virginia, Julia L. Roller

School of Professional and Continuing Studies Nonprofit Studies Capstone Projects

Green infrastructure is a necessary component of urban environments designed to mitigate climate instability and provide healthier living environments for urban residents. Discrimination and socio-economic status are some of the determining factors in the provision of green infrastructure, availability of green spaces, and outdoor programming available in urban communities. This paper describes an exploratory case study of the partnerships between municipal and nonprofit organizations involved in the revitalization of an impaired watershed in Richmond, Virginia. Preliminary findings suggest networking between agencies and nonprofits with strong mission alignment can increase organizational capacity by sharing specialized training and resources. Success may also …

Shell Calcification And Growth Of The Aquatic Snail Planorbella Trivolvis Under Low Calcium Conditions Typical Of Decalcified Northern Lakes, Shawn A. Witte

Biology Theses

The water calcium concentration of northern softwater lakes has declined to critically low levels due to numerous anthropogenic stressors, and the availability of calcium is expected to decline further. To assess the impact that critically low water calcium has on aquatic snail shell calcification and growth, juvenile Planorbella trivolvis were raised for 60 days in one of four treatments, each containing a different amount of dissolved calcium (0.64, 1.3, 2.5, and 5.1 mg/L). There was no difference in tissue weight or shell size among treatments, suggesting low water calcium concentrations do not impact adult body mass or size. However, snails …

Developmental And Behavioral Responses Of Early Life Stages Of Fathead Minnows (Pimephales Promelas) To Urban Effluents Treated With Advanced-Oxidation Processes, Amy Cavanaugh

Biology Theses

Wastewater Treatment Plants (WWTP) are the main vector for pharmaceutical and personal care products (PPCPs) to enter waterways. Many PPCPs are lipophilic, allowing them to bioaccumulate and biomagnify within aquatic organisms. PPCPs have been known to alter fish behavior and physiological processes, such as nesting defense and sex ratios, and produce an increase in deformities. Advanced oxidation processes (AOPs) are novel ways for treating WWTPs effluents that use hydroxyl radicals to indiscriminately breakdown PPCPs. In this study, fathead minnows (Pimephales promelas) were used to examine the biological effects of AOP-treated municipal effluent as they developed from eggs to …

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison K. Ludwig

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

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

Expanding The Conservation Genomics Toolbox: Incorporating Structural Variants To Enhance Genomic Studies For Species Of Conservation Concern, Stephanie J. Galla

Biology Faculty Publications and Presentations

Structural variants (SVs) are large rearrangements (>50 bp) within the genome that impact gene function and the content and structure of chromosomes. As a result, SVs are a significant source of functional genomic variation, that is, variation at genomic regions underpinning phenotype differences, that can have large effects on individual and population fitness. While there are increasing opportunities to investigate functional genomic variation in threatened species via single nucleotide polymorphism (SNP) data sets, SVs remain understudied despite their potential influence on fitness traits of conservation interest. In this future-focused Opinion, we contend that characterizing SVs offers the conservation genomics …

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …