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Articles 1741 - 1770 of 6306

Full-Text Articles in Terrestrial and Aquatic Ecology

Impact Of Covid-19 On The Us And Texas Economy: A General Equilibrium Approach, Lirong Liu, Steven S. Shwiff, Stephanie A. Shwiff, Maryfrances Miller Jan 2021

Impact Of Covid-19 On The Us And Texas Economy: A General Equilibrium Approach, Lirong Liu, Steven S. Shwiff, Stephanie A. Shwiff, Maryfrances Miller

United States Department of Agriculture Wildlife Services: Staff Publications

This paper examines the impact of COVID-19 on the US and Texas economy using a computable general equilibrium model, REMI PI+. We consider three scenarios based on economic forecasts from various sources, including the University of Michigan’s RSQE (Research Seminar in Quantitative Economics), IMF, and the Wi orld Bank. We report a GDP loss of $106 million (a 6% decline) with 1.2 million jobs lost (6.6%) in Texas in 2020. At the national level, GDP loss is $996 billion (a 5% decline) with 11.5 million jobs lost (5.5%) in the same year. By 2026, the aggregate total GDP loss in …


Conflict, Coexistence, Or Both? Cougar Habitat Selection, Prey Composition, And Mortality In A Multiple-Use Landscape, David C. Stoner, Mark A. Ditmer, Dustin L. Mitchell, Julie K. Young, Michael L. Wolfe Jan 2021

Conflict, Coexistence, Or Both? Cougar Habitat Selection, Prey Composition, And Mortality In A Multiple-Use Landscape, David C. Stoner, Mark A. Ditmer, Dustin L. Mitchell, Julie K. Young, Michael L. Wolfe

United States Department of Agriculture Wildlife Services: Staff Publications

Western North America is experiencing remarkable human population growth and land-use change. Irrigation and associated cultivation have led to colonization of urban-wildland interface (UWI) environments by mule deer (Odocoileus hemionus), and consequently, cougars (Puma concolor). In the wake of these changes, human-wildlife conflicts have increased in tandem with questions about long-term species conservation. To address these concerns, we fit 79 cougars with radio-telemetry collars in the Oquirrh Mountains near Salt Lake City, Utah (2002–2010). Our goal was to evaluate variation in cougar habitat selection, diet, and cause-specific mortality in a landscape dominated by urban, military, and industrial activities. We used …


Analyzing Interactions Among Migratory Elk And Semi-Permeable Fences Amongst A Highly Fragmented Landscape On The Blackfeet Reservation, Landon J. Magee Jan 2021

Analyzing Interactions Among Migratory Elk And Semi-Permeable Fences Amongst A Highly Fragmented Landscape On The Blackfeet Reservation, Landon J. Magee

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Large scale fences pose a threat to ungulate movement on the Blackfeet Reservation. Since the beginning of the last decade, the Blackfeet Reservation has experienced intense habitat fragmentation in the northern regions of the reservation, particularly in prime elk habitat that is believed to be along a migration corridor. One source of fragmentation has been the erection of a semi-permeable fence associated with a large bison ranch. The purpose of this study was to preliminarily assess potential interactions of elk (Cervus canadensis) and the semi-permeable bison fence as a precursor for further study. I worked in collaboration with …


Environmental Gradients And Physical Barriers Drive The Basin-Wide Spatial Structuring Of Mediterranean Sea And Adjacent Eastern Atlantic Ocean Prokaryotic Communities, Marta Sebastián, Eva Ortega-Retuerta, Laura Gómez-Consarnau, Marina Zamanillo, Marta Álvarez, Javier Arístegui, Josep M. Gasol Jan 2021

Environmental Gradients And Physical Barriers Drive The Basin-Wide Spatial Structuring Of Mediterranean Sea And Adjacent Eastern Atlantic Ocean Prokaryotic Communities, Marta Sebastián, Eva Ortega-Retuerta, Laura Gómez-Consarnau, Marina Zamanillo, Marta Álvarez, Javier Arístegui, Josep M. Gasol

Research outputs 2014 to 2021

The Mediterranean Sea is a miniature ocean divided by the Sicily Strait into two basins with a marked west to east trophic gradient and separated of the nearby eastern Atlantic Ocean by the Strait of Gibraltar. Here, we test the hypothesis that these physical and environmental barriers favor the development of specific prokaryotic assemblages, leading to changes in community structure both in the vertical and horizontal spatial scales. By analyzing taxonomic and phylogenetic diversity using amplicon sequence variants (ASVs) of the 16S rRNA gene, we show that there is indeed marked vertical segregation of prokaryotic groups, similar to that found …


Controls On Autotrophic Respiration, Heterotrophic Respiration, And Decomposition In Northern Forested Rivers, Renn Schipper Jan 2021

Controls On Autotrophic Respiration, Heterotrophic Respiration, And Decomposition In Northern Forested Rivers, Renn Schipper

Dissertations, Master's Theses and Master's Reports

Autotrophic respiration (AR), heterotrophic respiration (HR), and decomposition are important contributors to the carbon cycle in streams. It is important to understand how different environmental factors, such as canopy cover and dissolved organic carbon (DOC), influence these processes. DOC concentrations in northern forested streams are increasing, which may affect light and carbon availability. To examine the effects of DOC and canopy cover on these processes we measured gross primary production, ecosystem respiration and decomposition at 8 sites in 4 streams in the Upper Peninsula of Michigan and used quantile regression to estimate AR and HR. Among sites, AR and decomposition …


Metagenomic Identification And Classification Of The Mercury-Methylating Gene Hgca In Response To Water Table And Plant Functional Group Manipulations In Peat Soil, Madeline Peterson Jan 2021

Metagenomic Identification And Classification Of The Mercury-Methylating Gene Hgca In Response To Water Table And Plant Functional Group Manipulations In Peat Soil, Madeline Peterson

Dissertations, Master's Theses and Master's Reports

Methyl-mercury (MeHg) is a potent neurotoxin that threatens the health of humans and wildlife alike. Climate warming threatens to shift regional precipitation and climate regimes in peatland environments, which could destabilize northern peatlands and accelerate both Hg release from soil and MeHg production. Peatlands are among the leading hotspots for MeHg, yet little is known about the community composition or functional relationship of mercury-methylating microbes in response to varying environmental conditions. The recognized mercury-methylating genes responsible for this activity are the obligatory gene pair hgcA and hgcB. Metagenomic data from the full-factorial peatland mesocosm experiment PEATcosm was obtained to …


Denitrification And Nitrogen Fixation Commonly Co-Occur But Rates Vary Throughout The Year And In Different Environments, Kevin Nevorski Jan 2021

Denitrification And Nitrogen Fixation Commonly Co-Occur But Rates Vary Throughout The Year And In Different Environments, Kevin Nevorski

Dissertations, Master's Theses and Master's Reports

Denitrification and nitrogen fixation are nitrogen cycling processes that can occur simultaneously in streams but are rarely studied together. The overarching goal of this dissertation was to quantify temporal and spatial variation of these processes in streams across the USA, characterize the environmental drivers of that variation, and determine the role that denitrification plays in the carbon cycle. To characterize temporal variation in these processes, a 2-year study in the Pilgrim River in Michigan’s Upper Peninsula found no difference in rates among seasons but high day-to-day variation in rates of both processes (maximum daily change 4,390 μg N/m2/hr …


Regional Impacts Of Invasive Species And Climate Change On Black Ash Wetlands, Joseph Shannon Jan 2021

Regional Impacts Of Invasive Species And Climate Change On Black Ash Wetlands, Joseph Shannon

Dissertations, Master's Theses and Master's Reports

For more than a decade intensive research on the ecohydrology of black ash wetland ecosystems has been performed to understand these systems before they are drastically altered by the invasive species, emerald ash borer (EAB). In that time there has been little research aimed at the scale and persistence of the alterations. Three distinct but related research articles will be presented to demonstrate a method for moderate resolution mapping of black ash across its entire range, understand the relative impacts of EAB and climate change on probable future wetland conditions, and develop an experimental and modeling approach to quantify and …


Conservation Status And Natural History Of Ctenomys, Tuco-Tucos In Bolivia, Scott Lyell Gardner, Sebastian Botero-Cañola, Enzo Aliaga Rossel, Altangerel Tsogtsaikhan Dursahinhan, Jorge A. Salazar-Bravo Jan 2021

Conservation Status And Natural History Of Ctenomys, Tuco-Tucos In Bolivia, Scott Lyell Gardner, Sebastian Botero-Cañola, Enzo Aliaga Rossel, Altangerel Tsogtsaikhan Dursahinhan, Jorge A. Salazar-Bravo

Scott L. Gardner Publications

The genus Ctenomys consists of about 70 species and in addition to the Geomyidae of the Nearctic, Neotropical tuco-tucos represent a well-documented case of diversification in the subterranean biotype. Here we will: i) Provide an updated summary of the natural history of the 12 species of extant tuco-tucos from Bolivia; ii) Update information on distributions of each species; and iii) Using ecological niche modeling, evaluate recent and projected habitat transformation or habitat degradation within the known range of each species to provide a preliminary assessment of the preservation or conservation status of ctenomyids within Bolivia. We follow Gardner et al. …


Spatial Transferability Of Expert Opinion Models For American Beaver Habitat, Isidro Barela, Leslie M. Burger, Guiming Wang, Kristine O. Evans, Qingmin Meng, Jimmy D. Taylor Jan 2021

Spatial Transferability Of Expert Opinion Models For American Beaver Habitat, Isidro Barela, Leslie M. Burger, Guiming Wang, Kristine O. Evans, Qingmin Meng, Jimmy D. Taylor

United States Department of Agriculture Wildlife Services: Staff Publications

Species distribution models and habitat suitability models (HSMs) have become a popular tool in the conservation of biodiversity. However, the ability to predict species spatial distributions at sites beyond the data source sites (i.e., spatial transferability) is critical for the applications of HSMs in the management and conservation of rare or endangered species. The main objective of our study was to assess the predictive performance and spatial transferability of expert opinion models (EOMs). To build EOMs, we identified through extensive literature reviews 17 key landscape variables to characterize habitat use by American beaver (Castor canadensis). We developed 31 pairwise opinion …


Evidence For Continental-Scale Dispersal Of Antimicrobial Resistant Bacteria By Landfill-Foraging Gulls, Christina A. Ahlstrom, Mariëlle L. Van Toor, Hanna Woksepp, Jeffrey C. Chandler, John A. Reed, Andrew B. Reeves, Jonas Waldenström, Alan B. Franklin, David C. Douglas, Jonas Bonnedahl, Andrew M. Ramey Jan 2021

Evidence For Continental-Scale Dispersal Of Antimicrobial Resistant Bacteria By Landfill-Foraging Gulls, Christina A. Ahlstrom, Mariëlle L. Van Toor, Hanna Woksepp, Jeffrey C. Chandler, John A. Reed, Andrew B. Reeves, Jonas Waldenström, Alan B. Franklin, David C. Douglas, Jonas Bonnedahl, Andrew M. Ramey

United States Department of Agriculture Wildlife Services: Staff Publications

Anthropogenic inputs into the environment may serve as sources of antimicrobial resistant bacteria and alter the ecology and population dynamics of synanthropic wild animals by providing supplemental forage. In this study, we used a combination of phenotypic and genomic approaches to characterize antimicrobial resistant indicator bacteria, animal telemetry to describe host movement patterns, and a novel modeling approach to combine information fromthese diverse data streams to investigate the acquisition and long-distance dispersal of antimicrobial resistant bacteria by landfill-foraging gulls. Our results provide evidence that gulls acquire antimicrobial resistant bacteria from anthropogenic sources, which they may subsequently disperse across and between …


Food Habits Of Wintering Double-Crested Cormorants In The Mississippi Delta, Terrel W. Christie, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Carole R. Engle, Katie Hanson-Dorr, Anita M. Kelly Jan 2021

Food Habits Of Wintering Double-Crested Cormorants In The Mississippi Delta, Terrel W. Christie, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Carole R. Engle, Katie Hanson-Dorr, Anita M. Kelly

United States Department of Agriculture Wildlife Services: Staff Publications

Given its ubiquity, it is not surprising that agriculture, including fin fish aquaculture, contributes to food webs worldwide and is used by numerous wildlife for foraging and meeting other needs. Double-crested Cormorants (Phalacrocorax auritus) impact United States commercial aquaculture and are considered the primary avian predator in catfish (Ictalurus spp.) aquaculture facilities in the Mississippi Delta. Recent changes in aquaculture practices, regulatory policies, and decreased overall hectares in production prompted this study that assessed cormorant consumption of catfish in relation to their night roosts through surveys and diet analysis. Cormorants were collected from night roosts from October …


Environmental Correlates Of Genetic Variation In The Invasive European Starling In North America, Natalie R. Hofmeister, Scott J. Werner, Irby J. Lovette Jan 2021

Environmental Correlates Of Genetic Variation In The Invasive European Starling In North America, Natalie R. Hofmeister, Scott J. Werner, Irby J. Lovette

United States Department of Agriculture Wildlife Services: Staff Publications

Populations of invasive species that colonize and spread in novel environments may differentiate both through demographic processes and local selection. European starlings (Sturnus vulgaris) were introduced to New York in 1890 and subsequently spread throughout North America, becoming one of the most widespread and numerous bird species on the continent. Genome-wide comparisons across starling individuals and populations can identify demographic and/or selective factors that facilitated this rapid and successful expansion. We investigated patterns of genomic diversity and differentiation using reduced-representation genome sequencing of 17 winter-season sampling sites. Consistent with this species' high dispersal rate and rapid expansion history, …


Population Genomic Transformations Induced By Isolation Of Wild Bird Avian Influenza Viruses (Orthomyxoviridae) In Embryonated Chicken Eggs, Matthew W. Hopken, Antoinette J. Piaggio, K. L. Pabilonia, James Pierce, Theodore Anderson, Courtney Pierce, Zaid Abdo Jan 2021

Population Genomic Transformations Induced By Isolation Of Wild Bird Avian Influenza Viruses (Orthomyxoviridae) In Embryonated Chicken Eggs, Matthew W. Hopken, Antoinette J. Piaggio, K. L. Pabilonia, James Pierce, Theodore Anderson, Courtney Pierce, Zaid Abdo

United States Department of Agriculture Wildlife Services: Staff Publications

Isolation and cultivation of wild-type viruses in model organism cells or tissues is standard practice in virology. Oftentimes, the virus host species is distantly related to the species from which the culture system was developed. Thus, virus culture in these tissues and cells basically constitutes a host jump, which can lead to genomic changes through genetic drift and/or adaptation to the culture system. We directly sequenced 70 avian influenza virus (Orthomyxoviridae) genomes from oropharyngeal/cloacal swabs collected from wild bird species and paired virus isolates propagated from the same samples following isolation in specific-pathogen-free embryonated chicken eggs. The data were analyzed …


Estimation Of Wildlife Damage From Federal Crop Insurance Data, Sophie Mckee, Stephanie A. Shwiff, Aaron M. Anderson Jan 2021

Estimation Of Wildlife Damage From Federal Crop Insurance Data, Sophie Mckee, Stephanie A. Shwiff, Aaron M. Anderson

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Wildlife damage to crops is a persistent and costly problem for many farmers in the USA. Most existing estimates of crop damage have relied on direct assessment methods such as field studies conducted by trained biologists or surveys distributed to farmers. In this paper, we describe a new method of estimating wildlife damage that exploits federal crop insurance data. We focused our study on four crops: corn, soybean, wheat, and cotton, chosen because of their economic importance and their vulnerability to wildlife damage.

RESULTS: We determined crop-raiding hot spots across the USA over the 2015–2019 period and identified the …


Inefficiency Of Anthraquinone-Based Avian Repellents When Applied To Sunflower: The Importance Of Crop Vegetative And Floral Characteristics In Field Applications, Brandon Kaiser, Burton L. Johnson, Mike Ostlie, Scott J. Werner, Page E. Klug Jan 2021

Inefficiency Of Anthraquinone-Based Avian Repellents When Applied To Sunflower: The Importance Of Crop Vegetative And Floral Characteristics In Field Applications, Brandon Kaiser, Burton L. Johnson, Mike Ostlie, Scott J. Werner, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Blackbirds (Icteridae) cause significant damage to sunflower (Helianthus annuus L.) prompting the need for effective management tools. Anthraquinone-based repellents can reduce feeding by > 80% in laboratory settings, but require birds to learn the negative association through repellent ingestion. We evaluated an anthraquinone-based repellent applied directly to mature sunflower plants for its ability to reduce bird damage. We used captive male red-winged blackbirds (Agelaius phoeniceus) to evaluate efficacy of two anthraquinone-based formulations in varying concentrations and applied in a manner attainable by sunflower producers. We also assessed field application methods for repellent coverage and anthraquinone residues when …


Anthraquinone Repellent Seed Treatment On Corn Reduces Feeding By Wild Pigs, Nathan P. Snow, Joseph M. Halseth, Scott J. Werner, Kurt C. Vercauteren Jan 2021

Anthraquinone Repellent Seed Treatment On Corn Reduces Feeding By Wild Pigs, Nathan P. Snow, Joseph M. Halseth, Scott J. Werner, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are a destructive invasive species that cause extensive damage to agriculture throughout many regions of the world. In particular wild pigs damage corn more than any other crop, and most of that damage occurs immediately after planting when wild pigs excavate and consume planted seeds. We evaluated whether anthraquinone (AQ), a repellent, could be useful for protecting seed corn from consumption by wild pigs. Specifically, we conducted cafeteria-style tests at 16 bait sites for 6 nights using concentrations of: untreated, 0.5, 1.5, and 3.0% AQ by weight sprayed on whole-kernel corn in AL and …


The Evolutionary Consequences Of Human–Wildlife Conflict In Cities, Christopher J. Schell, Lauren Stanton, Julie K. Young, Lisa Angeloni, Joanna E. Lambert, Stewart W. Breck, Maureen H. Murray Jan 2021

The Evolutionary Consequences Of Human–Wildlife Conflict In Cities, Christopher J. Schell, Lauren Stanton, Julie K. Young, Lisa Angeloni, Joanna E. Lambert, Stewart W. Breck, Maureen H. Murray

United States Department of Agriculture Wildlife Services: Staff Publications

Human–wildlife interactions, including human–wildlife conflict, are increasingly common as expanding urbanization worldwide creates more opportunities for people to encounter wildlife. Wildlife–vehicle collisions, zoonotic disease transmission, property damage, and physical attacks to people or their pets have negative consequences for both people and wildlife, underscoring the need for comprehensive strategies that mitigate and prevent conflict altogether. Management techniques often aim to deter, relocate, or remove individual organisms, all of which may present a significant selective force in both urban and nonurban systems. Managementinduced selection may significantly affect the adaptive or nonadaptive evolutionary processes of urban populations, yet few studies explicate the …


Modeling Mongoose Rabies In The Caribbean: A Model-Guided Fieldwork Approach To Identify Research Priorities, Caroline C. Sauvé, Erin E. Rees, Amy T. Gilbert, Are R. Berentsen, Agathe Allibert, Patrick A. Leighton Jan 2021

Modeling Mongoose Rabies In The Caribbean: A Model-Guided Fieldwork Approach To Identify Research Priorities, Caroline C. Sauvé, Erin E. Rees, Amy T. Gilbert, Are R. Berentsen, Agathe Allibert, Patrick A. Leighton

United States Department of Agriculture Wildlife Services: Staff Publications

We applied the model-guided fieldwork framework to the Caribbean mongoose rabies system by parametrizing a spatially-explicit, individual-based model, and by performing an uncertainty analysis designed to identify parameters for which additional empirical data are most needed. Our analysis revealed important variation in output variables characterizing rabies dynamics, namely rabies persistence, exposure level, spatiotemporal distribution, and prevalence. Among epidemiological parameters, rabies transmission rate was the most influential, followed by rabies mortality and location, and size of the initial infection. The most influential landscape parameters included habitat-specific carrying capacities, landscape heterogeneity, and the level of resistance to dispersal associated with topography. Movement …


A Framework For Surveillance Of Emerging Pathogens At The Human-Animal Interface: Pigs And Coronaviruses As A Case Study, Kim M. Pepin, Ryan S. Miller, Mark Q. Wilber Jan 2021

A Framework For Surveillance Of Emerging Pathogens At The Human-Animal Interface: Pigs And Coronaviruses As A Case Study, Kim M. Pepin, Ryan S. Miller, Mark Q. Wilber

United States Department of Agriculture Wildlife Services: Staff Publications

Pigs (Sus scrofa) may be important surveillance targets for risk assessment and risk-based control planning against emerging zoonoses. Pigs have high contact rates with humans and other animals, transmit similar pathogens as humans including CoVs, and serve as reservoirs and intermediate hosts for notable human pandemics. Wild and domestic pigs both interface with humans and each other but have unique ecologies that demand different surveillance strategies. Three fundamental questions shape any surveillance program: where, when, and how can surveillance be conducted to optimize the surveillance objective? Using theory of mechanisms of zoonotic spillover and data on risk factors, …


Serological Responses Of Raccoons And Striped Skunks To Ontario Rabies Vaccine Bait In West Virginia During 2012–2016, Shylo R. Johnson, Dennis Slate, Kathleen M. Nelson, Amy J. Davis, Samual A. Mills, John T. Forbes, Kurt Vercauteren, Amy T. Gilbert, Richard B. Chipman Jan 2021

Serological Responses Of Raccoons And Striped Skunks To Ontario Rabies Vaccine Bait In West Virginia During 2012–2016, Shylo R. Johnson, Dennis Slate, Kathleen M. Nelson, Amy J. Davis, Samual A. Mills, John T. Forbes, Kurt Vercauteren, Amy T. Gilbert, Richard B. Chipman

United States Department of Agriculture Wildlife Services: Staff Publications

Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial inWest Virginia. Our objective was to evaluate raccoon …


Understanding Tolerance For An Invasive Species: An Investigation Of Hunter Acceptance Capacity For Wild Pigs (Sus Scrofa) In Texas, Hailey E. Mclean, Tara L. Teel, Alan Bright, Lauren M. Jaebker, John M. Tomecek, Maureen G. Frank, Rachael L. Connally, Stephanie A. Shwiff, Keith M. Carlisle Jan 2021

Understanding Tolerance For An Invasive Species: An Investigation Of Hunter Acceptance Capacity For Wild Pigs (Sus Scrofa) In Texas, Hailey E. Mclean, Tara L. Teel, Alan Bright, Lauren M. Jaebker, John M. Tomecek, Maureen G. Frank, Rachael L. Connally, Stephanie A. Shwiff, Keith M. Carlisle

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species and their establishment in new areas have significant impacts on the ecological, economic, and social well-being of our planet. Wild pigs (Sus scrofa) are one of the world’s most formidable invasive species, particularly in the United States. They cause significant damage to agriculture and ecosystems, and can transmit diseases to livestock, wildlife, and people. There is an inherent social dimension to the issue of wild pigs due in part to the fact that people hunt them. Hunting contributes to both the control and spread of this species. The objectives of this study were to: 1) determine hunters’ overall …


Factors Influencing Survival Rates Of Pronghorn Fawns In Idaho, Brett R. Panting, Eric M. Gese, Mary M. Conner, Scott Bergen Jan 2021

Factors Influencing Survival Rates Of Pronghorn Fawns In Idaho, Brett R. Panting, Eric M. Gese, Mary M. Conner, Scott Bergen

United States Department of Agriculture Wildlife Services: Staff Publications

Pronghorn (Antilocapra americana) occur throughout western North America. In Idaho, USA, following intensive hunting to reduce crop depredations in the late 1980s, pronghorn populations have not rebounded to desired levels. Because neonatal survival in ungulates is one factor limiting population growth, we evaluated cause‐specific mortality and the influence of intrinsic and extrinsic factors on survival rates of 217 radio‐collared pronghorn fawns across 3 study areas in Idaho during 2015–2016. For intrinsic variables, we determined the sex and body mass index (BMI) for each fawn. For extrinsic variables, we determined the abundance of predators and alternate prey, estimated the …


Avian Influenza A Viruses Reassort And Diversify Differently In Mallards And Mammals, Ketaki Ganti, Anish Bagga, Juliana Dasilva, Samuel S. Shepard, John R. Barnes, Susan A. Shriner, Katia Koelle, Anice C. Lowen Jan 2021

Avian Influenza A Viruses Reassort And Diversify Differently In Mallards And Mammals, Ketaki Ganti, Anish Bagga, Juliana Dasilva, Samuel S. Shepard, John R. Barnes, Susan A. Shriner, Katia Koelle, Anice C. Lowen

United States Department of Agriculture Wildlife Services: Staff Publications

Reassortment among co-infecting influenza A viruses (IAVs) is an important source of viral diversity and can facilitate expansion into novel host species. Indeed, reassortment played a key role in the evolution of the last three pandemic IAVs. Observed patterns of reassortment within a coinfected host are likely to be shaped by several factors, including viral load, the extent of viral mixing within the host and the stringency of selection. These factors in turn are expected to vary among the diverse host species that IAV infects. To investigate host differences in IAV reassortment, here we examined reassortment of two distinct avian …


Impacts Of A Large Invasive Mammal On Water Quality In Riparian Ecosystems, Sara Bolds, B. Graeme Lockaby, Stephen S. Ditchkoff, Mark D. Smith, Kurt C. Vercauteren Jan 2021

Impacts Of A Large Invasive Mammal On Water Quality In Riparian Ecosystems, Sara Bolds, B. Graeme Lockaby, Stephen S. Ditchkoff, Mark D. Smith, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are a highly invasive species in many regions of the world and can act as ecosystem engineers in areas where they are established. In riparian ecosystems, wild pigs may affect water quality parameters and introduce fecal bacteria, although previous studies have reported conflicting results. We propose four conditions that we believe are needed for an accurate assessment of wild pig impacts on water quality and address each one in our study. Water samples were collected between May 2018 and June 2019 in riparian watersheds on a privately owned property in Alabama that was densely populated by …


European Starling Nest‐Site Selection Given Enhanced Direct Nest Predation Risk, Bradley Blackwell, Thomas W. Seamans, Morgan Pfeiffer, Bruce N. Buckingham Jan 2021

European Starling Nest‐Site Selection Given Enhanced Direct Nest Predation Risk, Bradley Blackwell, Thomas W. Seamans, Morgan Pfeiffer, Bruce N. Buckingham

United States Department of Agriculture Wildlife Services: Staff Publications

The European starling (Sturnus vulgaris) is recognized, outside its native range, as an invasive species, and efforts to deter its nesting have generally been unsuccessful. Enhancing perceived risk at the nest site is a little‐explored route in developing a nest deterrent. Specifically, nest predation risk affects site selection, reproduction, antipredator behavior, and fitness in nesting birds. We questioned whether perceived predation risk as related to a snake model positioned inside a nest box, in striking form, moving, and present throughout the period of cavity site selection would induce European starlings to avoid or delay nest construction. We conducted our study …


A Framework To Evaluate Whether To Pool Or Separate Behaviors In A Multilayer Network, Annemarie Van Der Marel, Sanjay Prasher, Chelsea Carminito, Claire L. O'Connell, Alexa Phillips, Bryan M. Kluever, Elizabeth A. Hobson Jan 2021

A Framework To Evaluate Whether To Pool Or Separate Behaviors In A Multilayer Network, Annemarie Van Der Marel, Sanjay Prasher, Chelsea Carminito, Claire L. O'Connell, Alexa Phillips, Bryan M. Kluever, Elizabeth A. Hobson

United States Department of Agriculture Wildlife Services: Staff Publications

A multilayer network approach combines different network layers, which are connected by interlayer edges, to create a single mathematical object. These networks can contain a variety of information types and represent different aspects of a system. However, the process for selecting which information to include is not always straightforward. Using data on 2 agonistic behaviors in a captive population of monk parakeets (Myiopsitta monachus), we developed a framework for investigating how pooling or splitting behaviors at the scale of dyadic relationships (between 2 individuals) affects individual- and group-level social properties. We designed 2 reference models to test whether randomizing the …


Invasive Species In Puerto Rico: The View From El Yunque, Jess Zimmerman, Julissa Rojas-Sandoval, Aaron B. Shiels Jan 2021

Invasive Species In Puerto Rico: The View From El Yunque, Jess Zimmerman, Julissa Rojas-Sandoval, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Native flora and fauna of Puerto Rico have a long biogeographic connection to South America. Theory and empirical evidence suggest that islands, particularly those distantly isolated from the mainland, should be more susceptible to naturalizations and invasions of non-native species than continental areas. Anthropogenic disturbances can facilitate accidental and deliberate introductions of non-native species. In this study, we asked: What is the current status of introduced species within El Yunque National Forest (EYNF), the largest and most well-conserved forest area of Puerto Rico? To address this question, we reviewed the literature and surveyed local experts to identify introduced plant and …


Powassan Virus Experimental Infections In Three Wild Mammal Species, Nicole M. Nemeth, J. Jeffrey Root, Airn E. Hartwig, Richard A. Bowen, Angela M. Bosco-Lauth Jan 2021

Powassan Virus Experimental Infections In Three Wild Mammal Species, Nicole M. Nemeth, J. Jeffrey Root, Airn E. Hartwig, Richard A. Bowen, Angela M. Bosco-Lauth

United States Department of Agriculture Wildlife Services: Staff Publications

Powassan virus (POWV) is a tick-borne virus maintained in sylvatic cycles between mammalian wildlife hosts and ticks (primarily Ixodes spp.). There are two currently recognized lineages, POWV-lineage 1 (POWV-L1) and deer tick virus (DTV; lineage 2), both of which can cause fatal neurologic disease in humans. Increased numbers of human case reports in the northeastern and north central United States in recent years have fueled questions into POWV epidemiology. We inoculated three candidate wildlife POWV reservoir hosts, groundhogs (Marmota monax), striped skunks (Mephitis mephitis), and fox squirrels (Sciurus niger), with either POWV-L1 or DTV. …


Evaluating Lethal Toxicant Doses For The Largest Individuals Of An Invasive Vertebrate Predator With Indeterminate Growth, Shane R. Siers, Scott M. Goetz, Rachel M. Volsteadt, Melia G. Nafus Jan 2021

Evaluating Lethal Toxicant Doses For The Largest Individuals Of An Invasive Vertebrate Predator With Indeterminate Growth, Shane R. Siers, Scott M. Goetz, Rachel M. Volsteadt, Melia G. Nafus

United States Department of Agriculture Wildlife Services: Staff Publications

The brown treesnake (Boiga irregularis) was accidentally introduced to Guam and caused severe ecological and economic damages. Acetaminophen is an effective, low-risk oral toxicant for invasive brown treesnakes, and an automated aerial delivery system (ADS) has been developed for landscape-scale toxic bait distribution. A fixed dose of 80 mg of acetaminophen within a tablet inserted into a dead neonatal mouse (DNM) was lethal for all brown treesnakes in previous trials; however, these trials did not include very large individuals which are difficult to acquire for testing. Because most reptiles continue to grow throughout their lifespan, a small number …