Natural Resources and Conservation Commons^™

Water Scarcity And Fish Imperilment Driven By Beef Production, Brian D. Richter, Dominique Bartak, Peter Caldwell, Kyle Fankel Davis, Peter Debaere, Arjen Y. Hoekstra, Tianshu Li, Landon Marston, Ryan Mcmanamay, Mesfin Mekonnen, Benjamin L. Ruddell, Richard R. Rushforth, Tara J. Troy

Daugherty Water for Food Global Institute: Faculty Publications

Human consumption of freshwater is now approaching or surpassing the rate at which water sources are being naturally replenished in many regions, creating water shortage risks for people and ecosystems. Here we assess the impact of human water uses and their connection to water scarcity and ecological damage across the United States, identify primary causes of river dewatering and explore ways to ameliorate them. We find irrigation of cattle-feed crops to be the greatest consumer of river water in the western United States, implicating beef and dairy consumption as the leading driver of water shortages and fish imperilment in the …

Spatial And Temporal Behavioral Differences Between Angler-Access Types, Derek Kane, Mark A. Kaemingk, Christopher J. Chizinski, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Recreational angler surveys typically collect information on how anglers access a fishery. Yet, it is unclear how this information is useful for fisheries management and conservation. The objective of this study was to compare behavior (e.g., party size, time fished, and numbers of fish released and harvested) of bank and boat anglers, representing two angler-access types. Bank and boat anglers were surveyed across 29 Nebraska waterbodies from April through October, 2007–2017. We documented behavioral differences between bank and boat anglers that varied as a function of waterbody size and season. Patterns of party size, time fished, and numbers of fish …

Droughtscape, Spring 2020, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Spring 2020

Impacts Of Human Recreation On Nutrient Availability And Periphyton Abundance On The Niobrara River, Matthew Chen, Jessica Corman, Sydney Kimnach, Kayla Vondracek

UCARE: Research Products

In freshwater ecosystems, eutrophication can create many problems. Excess nutrients, like nitrogen or phosphorus, promote algal or cyanobacterial growth. This growth also leads to increased organic matter production and decomposition, a process that can reduce oxygen concentration in the water. When this happens, species diversity declines, transparency of the water declines, and anoxia may lead to fish kills . Of particular concern is the possibility of cyanobacteria blooms that create compounds toxic for humans. Many of the waters across Nebraska receive excessive nutrients from human activities, largely related to agriculture (Dickey 1982). However, there is one river, the Niobrara River, …

Understanding Sportsperson Retention And Reactivation Through License Purchasing Behavior, Matthew P. Hinrichs, Nathaniel B. Price, Matthew P. Gruntorad, Kevin L. Pope, Joseph J. Fontaine, Christopher J. Chizinski

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Most state and provincial fish and wildlife agencies have access to important information about patterns in sportsperson participation through their license databases. Using transaction data from Nebraska Game and Parks Commission’s electronic hunting and fishing license system, we tracked license purchases of Nebraska, USA, resident license holders in 2010 through 2017. We categorized sportspersons by gender and yearly purchases as hunting only (Hunter), fishing only (Angler), a combination of hunting and fishing (Hunter–Angler), or no purchases (Inactive). The probability of movement among active sportsperson groups was limited and varied little based on initial group participation. The Angler group had the …

Exploring How Graduates Of The Nebraska Water Leaders Academy Influence Community Capitals: Two Case Studies, Dakota Staggs

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

Natural resources are foundational to any community and so leadership regarding those resources is a key factor to consider in order to understand communities. The vitality and strength of a community, however, is not solely dependent upon the natural resources available to it but depends on the collection of assets and individuals within it. This study sought to understand how individual leaders, graduates of the Nebraska Water Leaders Academy, influence each of the seven community capitals outlined by Flora, Flora, and Gasteyer (2016), and how their individual civic capacity, as defined by Sun and Anderson (2012), contribute to community capacity. …

Transect Survey Biases And Correction Methods In Southern Africa, Erika Swenson, Larkin Powell

UCARE: Research Products

In southern Africa, transect surveys and distance-based analyses are often used to obtain density and population estimates for species in large reserves or management zones. However, these estimates may be biased by unnaturally large concentrations of animals at waterholes that are on or near the path of the transect. We used empirical survey data from the Namibrand Nature Reserve in southwest Namibia to parameterize spatial simulations in which we distributed gemsbok (Oryx gazella) on a grid along a 50-kilometer transect. We created multiple simulations with and without waterholes to determine how the proportion of animals clumped at the …

Talking Trash In The Big Apple: Mitigating Bird Strikes Near The North Shore Marine Transfer Station, Stephan J. Beffre, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Anthropogenic activities that concentrate wildlife near airports increases the risk of wildlife–aircraft collisions. Placing waste management facilities, natural areas, golf courses, and other landscape features near airports have the potential to attract wildlife hazardous to aviation. We conducted a 3-year study (March 2013–February 2016) to determine if the implementation of a Wildlife Hazard Mitigation Program (WHMP) would influence the bird use of a waste transfer station located near LaGuardia Airport, New York City, New York, USA. We conducted wildlife surveys during 3 phases: (1) no mitigation program and no waste transfer station, (2) active mitigation and no waste transfer station, …

Collective Effect Of Landfills And Landscape Composition On Bird–Aircraft Collisions, Morgan Pfeiffer, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Ninety-three percent of all reported bird strikes occur below 1,067 m, which based on the typical approach and departure angles of aircraft is within 8–13 km of an airport. Concomitantly, the Federal Aviation Administration and the International Civil Aviation Organization recommend that any feature that would attract hazardous wildlife to the approach and departure airspace be restricted. Thus, preventing the establishment of wildlife attractants, such as municipal solid waste landfills (MSWLFs) within 8 km or 13 km extents (U.S. and international recommendations, respectively) of airports, has been recommended to mitigate the risk of bird–aircraft collisions (strikes). However, robust evidence linking …

Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale

Daugherty Water for Food Global Institute: Faculty Publications

Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …

Weather And Exposure Period Affect Coyote Detection At Camera Traps, Anastasia E. Madsen, Lucia Corral Hurtado, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Abstract Camera traps are an increasingly popular means to monitor wildlife populations. However, like other techniques for measuring populations, camera traps are subject to sources of error that may bias population estimates. Past studies accounting for detection error have failed to account for a simple but potentially widely pervasive source of environmental error: weather conditions. Using 5,108,416 photographs from 804 scent‐lured camera traps deployed in western Nebraska, USA, during spring and autumn of 2014 and 2015, we analyzed the relationship between weather conditions (barometric pressure, wind speed, precipitation, and temperature) and coyote (Canis latrans) detection probability. Using binomial …

Testing A Key Assumption Of Using Drones As Frightening Devices: Do Birds Perceive Drones As Risky?, Conor C. Egan, Bradley Blackwell, Esteban Fernández-Juricic, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife managers have recently suggested the use of unmanned aircraft systems or drones as nonlethal hazing tools to deter birds from areas of human-wildlife conflict. However, it remains unclear if birds perceive common drone platforms as threatening. Based on field studies assessing behavioral and physiological responses, it is generally assumed that birds perceive less risk from drones than from predators. However, studies controlling for multiple confounding effects have not been conducted. Our goal was to establish the degree to which the perception of risk by birds would vary between common drone platforms relative to a predator model when flown at …

Friendship At The Feeding Station, Anisha Pokharel

Zea E-Books Collection

A young steppe eagle and his mother fly to Nepal from Mongolia, where Griffy, a Himalayan griffon, chases the hungry Steppe from the feeding station, but Garuda, a white-rumped vulture, intervenes and becomes Steppe's friend. Steppe's mother is angered at first, but learns the lesson that each species has its role to play.

Designed by Breanna Epp with Maeve Lausch

Factors Affecting Bait Site Visitation: Area Of Influence Of Baits, Jacquelyn E. Mcrae, Peter E. Schlichting, Nathan P. Snow, Amy J. Davis, Kurt C. Vercautern, John C. Kilgo, David A. Keiter, James C. Beasley, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

ABSTRACT Baiting is a fundamental strategy for the global management of wild pigs (Sus scrofa); however, little information exists on how anthropogenic bait affects wild pig movements on a landscape. We investigated factors that are important in determining the spatial area of attraction for wild pigs to bait (‘area of influence’ of a bait site) using data from Global Positioning System (GPS) collars and locations of bait sites. We monitored movements of wild pigs in 2 distinct study areas in the United States from February to September 2016 and used locational data using GPS collars to analyze the influence of …

A Rapid Population Assessment Method For Wild Pigs Using Baited Cameras At 3 Study Site, Peter E. Schlichting, James C. Beasley, Raoul K. Boughton, Amy J. Davis, Kim M. Pepin, Michael P. Glow, Ryan S. Miller, Kurt C. Vercautern, Jesse S. Lewis

United States Department of Agriculture Wildlife Services: Staff Publications

Reliable and efficient population estimates are a critical need for effective management of invasive wild pigs (Sus scrofa). We evaluated the use of 10‐day camera grids for rapid population assessment (RPA) of wild pigs at 3 study sites that varied in vegetation communities and wild pig densities. Study areas included Buck Island Ranch, Florida; Tejon Ranch, California; and the Savannah River Site, South Carolina, USA, during 2016–2018. Rapid population assessments grids were composed of baited camera traps spaced approximately 500 or 750 m apart. Two RPA grids were deployed per study site and each grid was deployed twice (4–6 months …

Relationships Between Survival And Habitat Suitability Of Semi- Aquatic Mammals, Isidro Barela, Leslie M. Burger, Jimmy Taylor, Kristine O. Evans, Ryo Ogawa, Lance Mcclintic, Guiming Wang

United States Department of Agriculture Wildlife Services: Staff Publications

Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche-based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), …

Effects Of Inactivated Mycobacterium Bovis Vaccination On Molokai-Origin Wild Pigs Experimentally Infected With Virulent M. Bovis, Pauline Nol, Morgan Wehte, Richard A. Bowen, Suelee Robbe-Austerman, Tyler Thacker, Kristina Lantz, Jack Rhyan, Laurie A. Baeten, Ramón A. Juste, Iker A. Sevilla, Christian Gortazar, Joaquín Vicente

United States Department of Agriculture Wildlife Services: Staff Publications

The wild pig population on Molokai, Hawaii, USA is a possible reservoir for bovine tuberculosis, caused by Mycobacterium bovis, and has been implicated in decades past as the source of disease for the island’s domestic cattle. Heat-inactivated vaccines have been effective for reducing disease prevalence in wild boar in Spain and could prove useful for managing M. bovis in Molokai wild pigs. We designed an experiment to test this vaccine in wild pigs of Molokai genetics. Fifteen 3–4-month-old pigs were orally administered 10⁶–10⁷ colony forming units (cfu) of heat-inactivated M. bovis (Vaccinates; n = 8; 0.2 …

Recharge Seasonality Based On Stable Isotopes: Nongrowing Season Bias Altered By Irrigation In Nebraska, Mikaela Cherry, Troy E. Gilmore, Aaron R. Mittelstet, Didier Gastmans, Vinicius Santos, John Gates

School of Natural Resources: Faculty Publications

The sustainability of groundwater resources for agricultural and domestic use is dependent on both the groundwater recharge rate and groundwater quality. The main purpose of this study was to improve understanding of the timing, or seasonality, of groundwater recharge through the use of stable isotopes. Based on 659 groundwater samples collected from aquifers underlying Natural Resources Districts in Nebraska, the isotopic composition of groundwater (δ 2H, δ 18O) was compared to that of precipitation by (a) mapping the isotopic composition of groundwater samples and (b) mapping a seasonality index for groundwater. Results suggest that for the majority of the state, …

Rabies Management Implications Based On Raccoon Population Density Indexes, Dennis Slate, Brandi D. Saidy, Ashlee Simmons, Kathleen M. Nelson, Amy Davis, Timothy P. Algeo, Stacey A. Elmore, Richard B. Chipman

United States Department of Agriculture Wildlife Services: Staff Publications

An estimate or index of target species density is important in determining oral rabies vaccination (ORV) bait densities to control and eliminate specific rabies variants. From 1997–2011, we indexed raccoon (Procyon lotor) densities 253 times based on cumulative captures on 163 sites from Maine to Alabama, USA, near ORV zones created to prevent raccoon rabies from spreading to new areas. We conducted indexing under a common cage trapping protocol near the time of annual ORV to aid in bait density decisions. Unique raccoons (n = 8,415) accounted for 68.0% of captures (n = 12,367). We recaptured raccoons 2,669 times. We …

Economic Estimates Of Invasive Wild Pig Damage To Crops In 12 Us States, Sophie Mckee, Aaron Anderson, Keith Carlisle, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

We report the results of a survey on invasive wild pig (Sus scrofa L.) damage and control in 12 US states (Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, and Texas). The crops chosen for this study represent the “second-tier” in terms of economic importance after the six crops that were the subject of Anderson et al. (2016). The survey was distributed by the USDA National Agricultural Statistical Service (NASS) in the summer of 2019 to a sample of producers in each of the states (except California) of the following six crops: hay, pecans (Carya …

Habitat Patchiness, Ecological Connectivity And The Uneven Recovery Of Boreal Stream Ecosystems From An Experimental Drought, Amelie Truchy, Romain Sarremejane, Timo Muotka, Heikki Mykra, David G. Angeler, Kaisa Lehosmaa, Ari Huusko, Richard K. Johnson, Ryan A. Sponseller, Brendan G. Mckie

School of Natural Resources: Faculty Publications

Ongoing climate change is increasing the occurrence and intensity of drought episodes worldwide, including in boreal regions not previously regarded as drought prone, and where the impacts of drought remain poorly understood. Ecological connectivity is one factor that might influence community structure and ecosystem functioning post-drought, by facilitating the recovery of sensitive species via dispersal at both local (e.g. a nearby habitat patch) and regional (from other systems within the same region) scales. In an outdoor mesocosm experiment, we investigated how impacts of drought on boreal stream ecosystems are altered by the spatial arrangement of local habitat patches within stream …

Individual And Population Fitness Consequences Associated With Large Carnivore Use Of Residential Development, Heather Johnson, David L. Lewis, Stewart W. Breck

United States Department of Agriculture Wildlife Services: Staff Publications

Large carnivores are negotiating increasingly developed landscapes, but little is known about how such behavioral plasticity influences their demographic rates and population trends. Some investigators have suggested that the ability of carnivores to behaviorally adapt to human development will enable their persistence, and yet, others have suggested that such landscapes are likely to serve as population sinks or ecological traps. To understand how plasticity in black bear (Ursus americanus) use of residential development influences their population dynamics, we conducted a 6-yr study near Durango, Colorado, USA. Using space-use data on individual bears, we examined the influence of use of residential …

Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

This study combines empirical predictive and economics models to estimate the cost of remediation for domestic wells exceeding suggested treatment thresholds for nitrates. A multiple logistic regression model predicted the probability of well contamination by nitrate, and a life cycle costing methodology was used to estimate costs of nitrate contamination in groundwater in two areas of Nebraska. In south-central Nebraska, 37% of wells were estimated to be at risk of exceeding a threshold of 7.5 mg/L as N, and 17% were at risk of exceeding 10 mg/L as N, the legal limit for human consumption in the United States. In …

Agricultural Drought Assessment In East Asia Using Satellite-Based Indices, Dong-Hyun Yoon, Won-Ho Nam, Hee-Jin Lee, Eun-Mi Hong, Song Feng, Brian D. Wardlow, Tsegaye Tadesse, Mark D. Svoboda, Michael Hayes, Dae-Eui Kim

School of Natural Resources: Faculty Publications

Drought is the meteorological phenomenon with the greatest impact on agriculture. Accordingly, drought forecasting is vital in lessening its associated negative impacts. Utilizing remote exploration in the agricultural sector allows for the collection of large amounts of quantitative data across a wide range of areas. In this study, we confirmed the applicability of drought assessment using the evaporative stress index (ESI) in major East Asian countries. The ESI is an indicator of agricultural drought that describes anomalies in actual/reference evapotranspiration (ET) ratios that are retrieved using remotely sensed inputs of land surface temperature (LST) and leaf area index (LAI). The …

Effects Of Deepwater Horizon Oil On Feather Structure And Thermoregulation In Gulls: Does Rehabilitation Work?, Katherine Horak, Nicole L. Barrett, Jeremy W. Ellis, Emma M. Campbell, Nicholas G. Dannemiller, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Impacts of large-scale oil spills on avian species are far-reaching.While media attention often focuses on lethal impacts, sub-lethal effects and the impacts of rehabilitation receive less attention. The objective of our study was to characterize effects of moderate external oiling and subsequent rehabilitation on feather structure and thermoregulation in gulls. We captured 30 wild ring-billed gulls (Larus delawarensis) and randomly assigned each individual to an experimental group: 1) controls, 2) rehabilitated birds (externally oiled, rehabilitated by washing), or 3) oiled birds (externally oiled, not rehabilitated). We externally oiled birds with weathered MC252 Deepwater Horizon oil (water for controls) …

Migratory Flyways May Affect Population Structure In Double‐Crested Cormorants, Steven J.A. Kimble, Brian S. Dorr, Katie C. Hanson-Dorr, Olin E. Rhodes Jr., Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Double‐crested cormorants (Phalacrocorax auritus) recovered from a demographic bottleneck so well that they are now considered a nuisance species at breeding and wintering grounds across the United States and Canada. Management of this species could be improved by refining genetic population boundaries and assigning individuals to their natal population. Further, recent radio‐telemetry data suggest the existence of Interior and Atlantic migratory flyways, which could reduce gene flow and result in substantial genetic isolation. In this study, we used 1,784 individuals collected across the eastern United States, a large panel of microsatellite markers developed for this species, and individuals banded as …

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is a fundamental method for delivering toxicants to pest species. Planning baiting strategies is challenging because bait-consumption rates depend on dynamic processes including space use and demographics of the target species. To determine cost-effective strategies for optimizing baiting, we developed a spatially explicit model of population dynamics using field-based measures of wild-pig (Sus scrofa) space use, bait consumption, and mortality probabilities. The most cost-effective baiting strategy depended strongly on the population reduction objective and initial density. A wide range of baiting strategies were cost-effective when the objective was 80% population reduction. In contrast, only a narrow range of …

Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat’s home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 …

Primary Atmospheric Drivers Of Dry And Wet Periods Over The U.S. Great Plains Within Cmip5 Models, Paul Flanagan, Jeffrey B. Basara, Elinor Martin, Rezaul Mahmood, Jason C. Furtado

School of Natural Resources: Faculty Publications

Precipitation variability is critical to the economic and ecosystem health of the United States Great Plains (GP). Whether from wet or dry extremes, changes in annual precipitation can lead to impacts on the health of the ecosystem and overall crop yield in a given year. To this end, wet and dry extremes have been investigated using the ERA-20C and CMIP5 dataset on an annual timescale to determine the ability of climate-scale simulations to resolve atmospheric drivers of precipitation variability. Results from the ERA-20C analysis show that specific atmospheric circulation anomalies can be detected which relate eddy geopotential height (EGH) anomalies …

The American Association Of State Climatologists' Recommendations And Best Practices For Mesonets, Christopher Fiebrich, Kevin R. Benson, Nathan L. Edwards, Stuart A. Foster, Rezaul Mahmood, Christopher A. Redmond, Megan Schargorodski, Jeffrey A. Andresen, Xiaomao Lin

School of Natural Resources: Faculty Publications

Over recent decades, mesoscale networks of automated, in-situ stations for weather monitoring have been developed across diverse regional settings. These networks, commonly referred to as mesonets, have originated independently, are funded at various levels and through various mechanisms, and serve a variety of constituencies and needs. While sharing commonalities, each network has unique strategic, design, and operational elements. As sensor and communications technologies evolve and the demand for environmental data to support decision making grows, mesonets are expected to play an increasing role in support of weather and climate services. Currently, there exists inconsistent functional practices and metadata reporting among …