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Visual Marking Of Ground Nests Might Attract Corvids, Emily M. O'Donovan, Mark S. Boyce

Human–Wildlife Interactions

For ground-nesting birds such as waterfowl, estimating nest survival is a crucial step in assessing population dynamics, and marking nests facilitates continuous monitoring. A conventional method for marking ground nests is to use an inconspicuous rod at the nest bowl and a wooden lathe 10 m away. Nests are visually marked to allow for greater efficiency when revisiting nests and to facilitate subsequent nest searching sessions. Anecdotal evidence suggests that common ravens (Corvus corax) and American crows (C. brachyrhynchos) might learn to recognize these nest markers, resulting in artificially inflated rates of nest predation. In 2017 …

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Human–Wildlife Interactions

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A Desert Tortoise–Common Raven Viable Conflict Threshold, Kerry L. Holcomb, Peter S. Coates, Brian G. Prochazka, Timothy Shields, William I. Boarman

Human–Wildlife Interactions

Since 1966, common raven (Corvus corax; raven) abundance has increased throughout much of this species’ Holarctic distribution, fueled by an ever-expanding supply of anthropogenic resource subsidies (e.g., water, food, shelter, and nesting substrate) to ecoregion specific raven population carrying capacities. Consequently, ravens are implicated in declines of both avian and reptilian species of conservation concern, including the California (USA) endangered and federally threatened Mojave desert tortoise (Gopherus agassizii; desert tortoise). While ravens are a natural predator of desert tortoises, the inter-generational stability of desert tortoise populations is expected to be compromised as annual juvenile survival is …

Common Raven Impacts On Nesting Western Snowy Plovers: Integrating Management To Facilitate Species Recovery, Cheryl Strong, Kriss K. Neuman, Jenny L. Hutchinson, Jamie K. Miller, Amber L. Clark, Lena Chang, Joanna Iwanicha, Elizabeth Feucht, Matthew J. Lau, David J. Lauten, Sarah Markegard, Benjamin Pearl, David L. Sherer, Rachel Tertes, Susie Tharratt, Travis Wooten

Human–Wildlife Interactions

The U.S. Pacific coast population of the western snowy plover (Charadrius nivosus nivosus; plover) has declined due to loss and degradation of coastal habitats, predation, and anthropogenic disturbance. The U.S. Fish and Wildlife Service listed the subspecies in 1993 as threatened under the Endangered Species Act due to the population declines and habitat loss. Predation of nests and chicks has been identified as an important cause of historic population declines, and thus, most predator management actions for this subspecies are focused on reducing this pressure. In recent years, common ravens (Corvus corax; ravens) have become the most …

A Rapid Assessment Function To Estimate Common Raven Population Densities: Implications For Targeted Management, Brianne E. Brussee, Peter S. Coates, Shawn T. O'Neil, Seth J. Dettenmaier, Pat J. Jackson, Kristy B. Howe, David Delehanty

Human–Wildlife Interactions

Common raven (Corvus corax; raven) populations have increased over the past 5 decades within the western United States. Raven population increases have been largely attributed to growing resource subsidies from expansion of human enterprise. Concomitantly, managers are becoming increasingly concerned about elevated adverse effects on multiple sensitive prey species, damage to livestock and agriculture, and human safety. Managers could benefit from a rapid but reliable method to estimate raven densities across spatiotemporal scales to monitor raven populations more efficiently and inform targeted and adaptive management frameworks. However, obtaining estimates of raven density is data- and resource-intensive, which renders …

Efficacy Of Manipulating Reproduction Of Common Ravens To Conserve Sensitive Prey Species: Three Case Studies, Corina A. Sanchez, Brianne E. Brussee, Peter S. Coates, Kerry L. Holcomb, Seth M. Harju, Timothy A. Shields, Mercy Vaughn, Brian G. Prochazka, Steven R. Mathews, Steffen Cornell, Chad V. Olson, David J. Delehanty

Human–Wildlife Interactions

Expansion of human enterprise across western North America has resulted in an increase in availability of anthropogenic resource subsidies for generalist species. This has led to increases in generalists’ population numbers across landscapes that were previously less suitable for their current demographic rates. Of particular concern are growing populations of common ravens (Corvus corax; ravens), because predation by ravens is linked to population declines of sensitive species. Ecosystem managers seek management options for mitigating the adverse effects of raven predation where unsustainable predator–prey conflicts exist. We present 3 case studies examining how manipulating reproductive success of ravens influences …

Thinking Like A Raven: Restoring Integrity, Stability, And Beauty To Western Ecosystems, John M. Marzluff, Matthias-Claudio Loretto, Cameron K. Ho, Georgia W. Coleman, Marco Restani

Human–Wildlife Interactions

Common ravens (Corvus corax; ravens) are generalist predators that pose a threat to several rare wildlife species in the western United States. Recent increases in raven populations, which are fueled by increased human subsidies—notably food, water, and nest sites—are concerning to those seeking to conserve rare species. Due to the challenges and inefficiencies of reducing or eliminating subsidies, managers increasingly rely on lethal removal of ravens. Over 125,000 ravens were killed by the U.S. Government from 1996 to 2019, and annual removals have increased 4-fold from the 1990s to mid-2010s. We contend that lethal removal of ravens, while capable …

Evaluating Common Raven Take For Greater Sage-Grouse In Oregon’S Baker County Priority Conservation Area And Great Basin Region, Frank F. Rivera-Milán, Peter S. Coates, Jacqueline B. Cupples, Michael Green, Patrick K. Devers

Human–Wildlife Interactions

The common raven (Corvus corax; raven) is a nest predator of species of conservation concern, such as the greater sage-grouse (Centrocercus urophasianus). Reducing raven abundance by take requires authorization under the Migratory Bird Treaty Act. To support U.S. Fish and Wildlife Service’s take decisions (e.g., those that authorize killing a specified proportion or number of individuals annually in a defined area), including the most recent one for Oregon’s Baker County Priority Area for Conservation (PAC), we modeled raven population dynamics under hypothetical scenarios with take rates ranging from below to above the maximum sustained yield (MSY; …

Increased Abundance Of The Common Raven Within The Ranges Of Greater And Gunnison Sage-Grouse: Influence Of Anthropogenic Subsidies And Fire, Jonathan B. Dinkins, Lindsey R. Perry, Jeffrey L. Beck, Jimmy D. Taylor

Human–Wildlife Interactions

The common raven (Corvus corax; raven) is native to North America and has increased in abundance, especially throughout western North America, during the last century. Human subsidies have facilitated raven dispersal into less suitable habitats and enabled these populations to maintain higher annual survival and reproduction. Concomitantly, overabundant raven populations are impacting other native at-risk species such as the greater sage-grouse (Centrocercus urophasianus) and potentially the Gunnison sage-grouse (C. minimus). Using Breeding Bird Survey data from 1995–2014, we evaluated raven count data to quantitatively describe changes in abundance and expansion into sagebrush (Artemisia …

Monograph Reduced Box Price: Managing Human–Deer Conflicts

Human–Wildlife Interactions

Order form for HWI monograph, Methods for Managing Human–Deer Conflicts in Urban, Suburban, and Exurban Areas. This monograph identifies challenges and benefits associated with many human–deer conflict mitigation actions as well as methods to monitor the response of deer populations to management actions. Deer exploit urban, suburban, and exurban areas where human populations provide anthropogenic attractants, either intentionally or inadvertently, which often leads to human–deer conflicts. Mitigating actions have varying degrees of efficacy and may not be effective or accepted in every situation. Wildlife and municipal managers must work together to seek methods to reduce attractants, mitigate conflicts, and perpetuate …

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Human–Wildlife Interactions

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Common Raven Impacts On The Productivity Of A Small Breeding Population Of Snowy Plovers, Matthew J. Lau, Benjamin H. Becker, David T. Press

Human–Wildlife Interactions

Common ravens (ravens; Corvus corax), an adaptable, synanthropic generalist, have thrived coincident with increasing human landscape modifications and fragmentation, consequently affecting their prey, which are often sensitive native and protected species. Ravens are a conservation concern for the protected western snowy plover (plover; Charadrius nivosus nivosus), causing low nest and chick survival in some breeding areas along the Pacific coast of North America. We used a long-term dataset from a breeding snowy plover monitoring program in Point Reyes National Seashore (PRNS) to investigate potential impacts of ravens on snowy plover nest and fledging success. Between 2002 and 2020, …

Estimating Trends Of Common Raven Populations In North America, 1966–2018, Seth M. Harju, Peter S. Coates, Seth J. Dettenmaier, Jonathan B. Dinkins, Pat J. Jackson, Michael P. Chenaille

Human–Wildlife Interactions

Over the last half century, common raven (Corvus corax; raven) populations have increased in abundance across much of North America. Ravens are generalist predators known to depredate the eggs and young of several sensitive species. Quantifying raven population increases at multiple spatial scales across North America will help wildlife resource managers identify areas where population increases present the greatest risk to species conservation. We used a hierarchical Bayesian modeling approach to analyze trends of standardized raven counts from 1966 to 2018 using Breeding Bird Survey data within each Level I and II ecoregion of the United States and Canada. …

A Novel Technique To Improve Capture Success Of Common Ravens, Lindsey R. Perry, Terrah M. Owens, Zachary T. Slick, Jimmy D. Taylor, Jonathan B. Dinkins

Human–Wildlife Interactions

Traditional trapping techniques for common ravens (Corvus corax; raven) require significant effort, often produce low capture rates, and cannot be used in some situations. We designed a 3-m noose pole to secure ravens from nocturnal roost locations while using a strobe spotlight to temporarily disorient them. We collected measures of trapping efficiency and contrasted them with padded leghold traps also used in the study. We effectively implemented our noose pole method in July and August of 2018, 2019, and 2020 in the Baker and Cow Lakes sage-grouse (Centrocercus urophasianus) Priority Areas of Conservation in eastern Oregon, …

Raven Control From A Conservation Biology Perspective, David J. Delehanty

Human–Wildlife Interactions

The common raven (Corvus corax; raven) is a large, highly intelligent passerine songbird with a Holarctic distribution attributable to a high degree of plasticity in its foraging and nesting behavior. Historically, ravens have received special attention in human culture, being either respected or vilified. In the western United States, ravens are exploiting the expanding human enterprise, which provides them with unintended subsidies of food, water, and breeding locations, allowing ravens to expand their range and increase in population density and resulting in raven depredation threatening species of conservation concern. From a conservation biology perspective, increased raven populations present …

Inter- And Intra-Annual Effects Of Lethal Removal On Common Raven Abundance In Nevada And California, Usa, Shawn T. O'Neil, Peter S. Coates, Julia C. Brockman, Pat J. Jackson, Jack O. Spencer Jr., Perry J. Williams

Human–Wildlife Interactions

Populations of common ravens (Corvus corax; ravens) have increased rapidly within sagebrush (Artemisia spp.) ecosystems between 1960 and 2020. Although ravens are native to North America, their population densities have expanded to levels that negatively influence the population dynamics of other wildlife species of conservation concern, such as greater sage-grouse (Centrocercus urophasianus) and desert tortoises (Gopherus agassizii). For this reason, lethal removal, such as the application of the avicide DRC-1339, has been used to manage raven numbers at local scales and under certain circumstances. Because the relative effectiveness of DRC-1339 in reducing raven …

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Human–Wildlife Interactions

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Smart: A Science-Based Tiered Framework For Common Ravens, Seth J. Dettenmaier, Peter S. Coates, Cali L. Roth, Sarah C. Webster, Shawn T. O'Neil, Kerry L. Holcomb, John C. Tull, Pat J. Jackson

Human–Wildlife Interactions

Large-scale increases and expansion of common raven (Corvus corax; raven) populations are occurring across much of North America, leading to increased negative consequences for livestock and agriculture, human health and safety, and sensitive species conservation. We describe a science-based adaptive management framework that incorporates recent quantitative analyses and mapping products for addressing areas with elevated raven numbers and minimizing potential adverse impacts to sensitive species, agricultural damage, and human safety. The framework comprises 5 steps: (1) desktop analysis; (2) field assessments; (3) comparison of raven density estimates to an ecological threshold (in terms of either density or density …

In The News, Ike Ionel, Jessica Tegt

Human–Wildlife Interactions

Items in the news.

Sharing Science Through Shared Values, Goals, And Stories: An Evidence-Based Approach To Making Science Matter, Bethann Garramon Merkle, Evelyn Valdez-Ward, Priya Shukla, Skylar R. Bayer

Human–Wildlife Interactions

Scientists in and beyond academia face considerable challenges to effectively sharing science, including lack of time and training, systemic disincentives, and the complexity of the modern media/attention landscape. Considering these constraints, 3 achievable shifts in mindset and practice can substantively enhance science communication efforts. Here, we provide evidence-based and experientially informed advice on how to center shared values, articulate science communication goals, and leverage the power of stories to advance our communication goals in connection with the values we share with our stakeholders. In addition to a discussion of relevant, foundational principles in science communication, we provide actionable recommendations and …

Common Raven Nesting And Spatial Distancing On Power Lines In Southeast Idaho, Usa, Quinn R. Shurtliff, Jericho C. Whiting

Human–Wildlife Interactions

Common raven (Corvus corax; raven) abundance and distribution have increased in western North America in recent decades, facilitated by anthropogenic subsidies and other environmental changes. Electrical power transmission line structures provide nesting substrates for ravens. When these structures transect landscapes where natural nest substrates are limited, they may facilitate raven predation on eggs and juveniles of sensitive avian and reptile species. Little information is available regarding raven nest density trends on adjacent power lines or how raven territorial behavior influences spatial partitioning of nests, and hence, nest density. This knowledge would be valuable for managers of sensitive prey …

Synthesis Of Nest Predation Impacts Of Common Ravens On Sensitive Avian Species, Peter S. Coates, William C. Webb, Seth J. Dettenmaier, Seth M. Harju, David J. Delehanty

Human–Wildlife Interactions

Decades of mounting scientific evidence have revealed that common raven (Corvus corax; raven) population numbers have been increasing across nearly all regions of their geographic range in North America. Concomitantly, numerous native wildlife species have experienced elevated predation rates from ravens as populations have increased and expanded their range. Managers are concerned that increased raven predation of many threatened and endangered avian species in the U.S. and Canada during nesting periods may be hampering species recovery. We explored the literature to aggregate existing knowledge and evaluate the impacts of raven predation on nests and young of sensitive avian …

A Decision Tool To Identify Population Management Strategies For Common Ravens And Other Avian Predators, Andrea F. Currylow, Brenda J. Hanley, Kerry L. Holcomb, Timothy Shields, Stephen Boland, William I. Boarman, Mercy Vaughn

Human–Wildlife Interactions

Some avian species have developed the capacity to leverage resource subsidies associated with human manipulated landscapes to increase population densities in habitats with naturally low carrying capacities. Elevated corvid densities and new territory establishment have led to an unsustainable increase in depredation pressure on sympatric native wildlife prey populations as well as in crop damage. Yet, subsidized predator removal programs aimed at reducing densities are likely most effective longer-term when conducted in tandem with subsidy control, habitat management, and robust assessment monitoring programs. We developed decision support software that leverages stage structured Lefkovitch population matrices to compare and identify treatment …

Frontier: Autonomy In Detection, Actuation, And Planning For Robotic Weeding Systems, Piyush Pandey, Hemanth Narayan Dakshinamurthy, Sierra N. Young

Civil and Environmental Engineering Faculty Publications

Weeds are a persistent and significant problem in agricultural production. Weeds, which tend to grow and produce very rapidly, compete with crops for critical resources, which can significantly reduce crop yields (Zimdahl, 2007). Herbicides are one of the most common and inexpensive approaches to controlling weeds; however, their continued and widespread use has prompted concerns due to off-target movement and steadily rising herbicide-resistant weed populations (Westwood et al., 2018). Given the significance of increasing herbicide-resistant weed populations and economic pressures to reduce costs associated with weeding, there is a need to implement more sustainable weed management approaches. Integrated weed management …

Spatial Modeling Of Common Raven Density And Occurrence Helps Guide Landscape Management Within Great Basin Sagebrush Ecosystems, Sarah C. Webster, Shawn T. O'Neil, Brianne E. Brussee, Peter S. Coates, Pat J. Jackson, John C. Tull, David J. Delehanty

Human–Wildlife Interactions

Common ravens (Corvus corax; ravens) are a behaviorally flexible nest predator of several avian species, including species of conservation concern. Movement patterns based on life history phases, particularly territoriality of breeding birds and transiency of nonbreeding birds, are thought to influence the frequency and efficacy of nest predation. As such, predicting where on the landscape territorial resident and non-territorial transient birds may be found in relation to the distribution of sensitive prey is of increasing importance to managers and conservationists. From 2007 to 2019, we conducted raven point count surveys between mid-March and mid-September across 43 different field …

Identification And Mitigation Of Harmful Algal Blooms In Mantua Reservoir, Jeffrey Kennedy, Timothy Place, Tyler Wallace, Steven White, Carolina Williams

Civil and Environmental Engineering

Cyanobacteria, also known as blue-green algae, are capable of emitting cyanotoxins which are harmful to humans and animals. Harmful Algal Blooms (HABs) occur when cyanobacteria multiply to great densities. Mantua Reservoir in Box Elder County, UT, experiences seasonal HABs, which has resulted in seasonal reservoir closures.

The EnVision team investigated the cause of HABs at Mantua Reservoir by collecting samples from the reservoir’s known point sources and frequently visited recreation areas. The samples were analyzed to determine total phosphorus, nitrate, and cyanotoxin concentrations. The team concluded that excessive phosphorus loading in the reservoir is most culpable for the annual HABs …

Comparison And Evaluation Of Two Sensors For Dynamic Measuring Of Foam Level In Single-Use Bioreactors, Alyssa Cisneros, Harley Cragun, Crystal Rain Fowler, Mikelle Kearnes, Annika Saunders

Biological Engineering

Single Use Bioreactors (SUBs) are used for microbial cell culture for many industries, such as cell cultures of pilot-studies, food, and cosmetics¹. Foaming in bioreactors is common and is responsible for the fouling of equipment.

• The goal of the project is to test and develop two possible dynamic foam level sensors for the 30 and 300L SUBs

Objectives:

1. Manufacture a scalable foam sensor housing unit

2. Create a program that allows for ease of sensor use when implemented into controller

3. Safe for biological cultures

4. Test the system to ensure accurate and simple sensor output …

Computational Model Of Angiogenesis In Wet Age-Related Macular Degeneration, Kelsey Bradshaw, Michael Cotner, Jacilyn Fielding, Andrew Kjar, Teren Teeples

Biological Engineering

Age-Related Macular Degeneration (AMD)

• Leads to vision loss and blindness

• Localized to subretinal layers (Figure 1.)

Electrocoagulation For Removal Of Nitrates From Fgd Wastewater, Jacob Watkins, Julissa Van Renselaar, Amanda Moravek, Tallon Beckstrom, Shaylynn Cannon

Biological Engineering

Flue gas desulfurization (FGD) processes are often utilized to mitigate pollution from coal-based plants by removing sulfur oxides¹. However, FGD wastewater streams still contain pollutants such as nitrates that must undergo further treatment². The Environmental Protection Agency (EPA) has Effluent Limitation Guidelines (ELG) that dictate the allowable concentrations of the contaminants in FGD wastewater effluent. While common treatment approaches can meet these requirements, efficiency drops with chemical concentration flux, which is a common situation with FGD wastewater. A novel method that could both meet ELG requirements and handle chemical concentration flux is electrocoagulation (EC). EC is able to target a …

Study Protocol For A Randomized Controlled Trial Comparing Two Low-Intensity Weight Loss Maintenance Interventions Based On Acceptance And Commitment Therapy Or Self-Regulation, Jason Lillis, Leah Schumacher, J. Graham Thomas, Michael E. Levin, Shira Dunsiger, Jessica L. Unick, Erin Evans, Jacqueline F. Hayes, Rena R. Wing

Psychology Faculty Publications

Background: Weight regain is common following behavioral obesity treatment and attenuates many of the benefits of initial weight loss. This paper describes a randomized controlled trial that will evaluate the efficacy of two low-contact weight loss maintenance interventions based on Acceptance and Commitment Therapy (ACT) and self-regulation (SR). Potential mechanisms of action and moderators of treatment effects will also be evaluated.

Methods: Adults (anticipated N=480)with overweight or obesity will complete an initial 3-monthonline weight loss program (Phase 1). Participants who achieve ≥4 kg weight loss (anticipated N=288) will then be randomized to an ACT or SR weight loss maintenance intervention. …