Environmental Sciences Commons^™

The Influence Of Individual Strategies On Cougar Ecology: Insights From Predation, Space Use, And Reproduction, Kristin Nicole Engebretsen

All Graduate Theses and Dissertations, Fall 2023 to Present

Carnivores are ecologically important to global ecosystems because they interact with their prey species and other carnivores in a variety of ways. Many carnivores have suffered habitat loss and persecution by humans, which has led some populations to become imperiled or locally extirpated. Despite these challenges, cougars (Puma concolor) continue to exist across North, Central, and South America. They exhibit behavioral adaptation across their wide range, thriving in terrain that ranges from temperate forests, to steppe scrub, to rainforest, to rugged deserts. Across these diverse ecosystems, cougars can successfully establish territories, hunt prey, and raise young to persist …

Livestock Producers' Perceptions Of The American Black Vulture Conflict In The Midwestern United States, Marian L. Wahl, Brooke Mcwherter, Patrick A. Zollner, Zhao Ma, Grant C. Burcham, Lee A. Humberg, Brian M. Kluever

USDA Wildlife Services: Staff Publications

Human‐wildlife interactions are present wherever both humans and wildlife are found. Interactions can be positive or negative for humans and can include impacts that range from damage to property, agriculture, health and human safety, to emotional effects. Livestock‐wildlife interactions form a major component of human‐wildlife conflicts with foci often centered on the implications of livestock predation by wildlife. While most vulture species are obligate scavengers, several species, including the American black vulture (Coragyps atratus), may attack weak or newborn livestock. Black vulture populations and distributions are expanding in the Midwestern U.S., and attacks create a novel problem for …

Predator Telemetry Informs Temporal And Spatial Overlap With Stocked Salmonids In Lake Huron, David G. Fielder, Todd A. Hayden, Thomas R. Binder, Brian S. Dorr, Heidi A. Currier

USDA Wildlife Services: Staff Publications

Double-Crested Cormorants (Phalacrocorax auratus), Walleyes (Sander vitreus), and Lake Trout (Salvelinus namaycush) are migratory predators that undergo extensive movements in Lake Huron. Stocking of juvenile salmonid fish (Oncorhynchus and Salmo sp.) is an important component of fishery management in Lake Huron and assessing the spatial and temporal extent of predator movements is a useful consideration for determining when and where to stock juvenile fish to reduce predation and maximize survival. Previous investigation indicated that some Walleyes migrate to the main basin of Lake Huron in spring from Saginaw Bay. Similarly, telemetry studies of Lake Trout movement in Lake Huron have …

Science‐Driven Guidelines Needed To Better Manage And Conserve Black Vultures In North America, Scott A. Rush, Neil J. Buckley, Patrick A. Zollner, Bryan M. Kluever, Brooke Mcwherter, Grant C. Burcham, Zhao Ma, Marian L. Wahl, Adrián Naveda‐Rodríguez

USDA Wildlife Services: Staff Publications

Black vultures (Coragyps atratus) provide invaluable ecological services through disposal of carrion and the mobilization of energy within the landscape. Human‐wildlife conflicts with these birds have increased as populations have grown and the species distribution has expanded. We identify critical science needed to understand conflict between black vultures and humans to inform effective management of this species in North America. It is imperative that diagnostic criteria supporting the identification of the impacts of black vulture on livestock be standardized and verified. Management guidelines that take these criteria into account will enable reduction in the potential for black‐vulture‐farmer conflict …

Stress And Predation Impacts On North American Quail Translocations, Curt A. Vandenberg, Sarah A. Currier, Jeffrey G. Whitt, Kelly S. Reyna

National Quail Symposium Proceedings

Translocations have been used in attempts to bolster or restore native quail populations for >150 years, often with little success. However, with some northeastern United States quail populations undetectable or extirpated, and others across the United States on the extreme decline, translocation as a tool for quail population restoration is becoming increasingly popular. Two factors contributing to translocation failure are physiological stress and predation. Chronic stress associated with translocations can result in weight loss, reduced immune system function, suppressed reproduction, and an altered fight-or-flight response. These stress-induced responses increase vulnerability to predation, the primary cause of quail mortality. Here, we …

Diurnal Occurrence Of Great-Horned Owls On Northern Bobwhite Hunting Properties In Southwest Georgia, Justin A. Rectenwald, Philip M. Coppola, Theron M. Terhune Ii, D. Clay Sisson, James A. Martin

National Quail Symposium Proceedings

Understanding interactions between prey species and their predators is essential to discerning the ecology and management fundamentals of a species. Great-horned owls (Bubo virginianus) have long been considered an opportunistic predator of northern bobwhite (Colinus virginianus; hereafter, bobwhite) and recent studies have demonstrated that bobwhite survival is reduced at higher great-horned owl densities (Rectenwald et al. 2021). Managers on quail properties often mechanically remove live oak (Quercus virginiana) hammocks as part of larger predation management plans to reduce the amount of suitable predator habitat. While scattered live oaks are typically left for aesthetic purposes, …

Comparing Molecular Methods To Estimate Fish Stomach Contents And Gastric Evacuation Rates: Implications For Measuring The Impacts Of Predation On Central Valley Chinook Salmon, Cory M. Dick

Cal Poly Humboldt theses and projects

Juvenile Chinook Salmon (Oncorhynchus tshawytscha) migrating through the Sacramento – San Joaquin Delta (the Delta) in central California have higher mortality rates than salmonids migrating through other west coast estuaries. Some hypotheses for high mortality rates include entrainment into water export facilities, physical alterations of the river system, and predation. Of these factors, predation is considered the least understood but may have the largest impact. Predation from large populations of non-native piscivorous fishes in the Delta is believed to effect abundances of Central Valley Chinook salmon, however sufficient data supporting this hypothesis is scarce. In this study, I …

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

USDA 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 …

Economic Effects Of Predation By Scaup On Baitfish And Sportfish Farms, Carole R. Engle, Stephen Clements, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Anita M. Kelly

USDA Wildlife Services: Staff Publications

Fish-eating birds have been found to consume baitfish and sportfish raised on farms in the United States. Understanding the on-farm economic effects of such wildlife conflicts is essential for wildlife management agencies to make informed decisions. Lesser scaup, while not widely considered a fisheating bird, will consume farmed fish. Baitfish and sportfish farms in Arkansas (the major baitfish and sportfish producingstate in the U.S.) were surveyed to gather data on the cost of protecting farm crops from scaup. The values of lost sales revenue from the various species of baitfish and sportfish consumed by scaup were estimated based on a …

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

USDA 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 …

Effects Of Freshwater Crayfish On Influenza A Virus Persistence In Water, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner

USDA Wildlife Services: Staff Publications

Several investigations have recently assessed the ability of some aquatic invertebrates to act as tools for avian influenza A virus (IAV) surveillance as well as their potential role(s) in IAV ecology. Because of this, as well as the high IAV seroprevalence rates noted in select mesocarnivores that commonly inhabit aquatic and semi-aquatic habitats, we evaluated the effects that freshwater crayfish have on IAV in water at three dose levels and monitored for the presence of IAV in crayfish tissues (gill and green gland) and haemolymph at multiple time points. At relatively high, medium 432 and low (approximately 10 , 10 …

Cats And Conservationists: The Debate Over Who Owns The Outdoors, Dara M. Wald, Anna L. Peterson

New Directions in the Human-Animal Bond

Cats and Conservationists is the first multidisciplinary analysis of the heated debate about free-roaming cats. The debate pits conservationists against cat lovers, who disagree both on the ecological damage caused by the cats and the best way to manage them. An impassioned and spirited conflict, it also sheds light on larger questions about how we interpret science, incorporate diverse perspectives, and balance competing values in order to encourage constructive dialogue on contentious social and environmental issues.

On one side of the cat debate stand many environmentalists, especially birders and conservation organizations, who believe that outdoor cats seriously threaten native wildlife. …

Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon

Cal Poly Humboldt theses and projects

Survival of juvenile ungulates is known to be highly variable, yet it is fundamental to understanding the dynamics and trends of wildlife populations. Factors influencing calf survival are poorly understood in northwestern California where Roosevelt elk (Cervus canadensis roosevelti) are known to exist. The objectives of this study were 1) to estimate summer and annual survival rates and determine recruitment rates for Roosevelt elk calves in the area, 2) to evaluate differences in calf survival by examining the effects of individual and population level covariates on summer and annual calf survival, 3) to identify factors influencing the timing …

Resurgence Of An Apex Marine Predator And The Decline In Prey Body Size, Jan Ohlberger, Daniel E. Schindler, Eric J. Ward, Timothy E. Walsworth, Timothy E. Essington

Watershed Sciences Faculty Publications

In light of recent recoveries of marine mammal populations worldwide and heightened concern about their impacts on marine food webs and global fisheries, it has become increasingly important to understand the potential impacts of large marine mammal predators on prey populations and their life-history traits. In coastal waters of the northeast Pacific Ocean, marine mammals have increased in abundance over the past 40 to 50 y, including fish-eating killer whales that feed primarily on Chinook salmon. Chinook salmon, a species of high cultural and economic value, have exhibited marked declines in average size and age throughout most of their North …

Experimental Assessment Of Predation Risk For Juvenile Green Sturgeon, Acipenser Medirostris, By Two Predatory Fishes, S. Baird, A. E. Steel, D. E. Cocherell, Jamilynn B. Poletto, R. Follenfant, N. A. Fangue

School of Natural Resources: Faculty Publications

No abstract provided.

Changes In Hatchery Subsidies Of Chinook Salmon In The Salish Sea: Implications For Predators, Fisheries, And Conservation, Benjamin Nelson, Eric John Ward, Ole Shelton, Joseph H. Anderson

Salish Sea Ecosystem Conference

Historically, salmon hatcheries were designed to increase fishery production and to recover depleted native populations. As demands of human protein consumption increase and wild populations continue to decline due to anthropogenic impacts like climate change and habitat loss, hatcheries and stocking programs will be called on to provide food security and to supplement threatened populations. Since 1950 over 3.7 billion Chinook salmon have been released into the Salish Sea and its tributaries in Washington State and southern British Columbia. However, relatively little research has been conducted that considers the impact of hatchery subsidies on estuarine and nearshore marine ecosystems in …

Interannual Variation In Early Marine Survival Patterns Of Puget Sound Steelhead Smolts Indicates Shifting Predation Pressures, Barry A. Berejikian, Megan Moore, Steve Jeffries

Salish Sea Ecosystem Conference

Marine survival of steelhead smolts during their two week migration from river mouths to the Strait of Juan de Fuca has been estimated at 20% or less for several populations originating in Puget Sound. Low survival rates likely reduce overall smolt-to-adult return rates and limit recovery of Puget Sound steelhead populations. Harbor seals are generalist predators known to eat juvenile salmon in the Salish Sea. Harbor seals were captured in 2014 (12 seals) and 2016 (16 seals) and outfitted with acoustic telemetry receivers and GPS tags to quantify likely predation events and estimate foraging area overlap with acoustically tagged steelhead …

Foraging Opportunity: A Method Of Monitoring Shorebird Migration And Overwintering Sites In A Changing Environment, James Rourke, Wendell Challenger, Ron Ydenberg

Salish Sea Ecosystem Conference

Roberts Bank within the Fraser River estuary, BC contains important migratory stopover and overwintering habitat for shorebirds such as the western sandpiper (Calidris mauri) and the Pacific dunlin (Calidris alpina pacifica). Shorebirds are especially abundant during northward migration, with single-day counts numbering into the hundreds of thousands of birds. Previous research and ecological theory have demonstrated that site usage by shorebirds is influenced by numerous factors, including prey availability and predation risk. We developed a concept termed “foraging opportunity” that quantifies shorebird food availability (biofilm, meiofauna, and macrofauna) in relation to predation danger from hunting falcons. Foraging opportunity was determined …

Patch Size And Nest Density Influence Nest Survival, Victoria L. Simonsen, Joseph J. Fontaine

National Quail Symposium Proceedings

Nest predation is the primary cause of avian nest failure and therefore an important driver of avian population growth. Studies indicate that landscape context plays an important role in nest success, and although this is widely attributed to changes in nest predator communities, landscape context also influences nest density which affects predator search area and effort. Much debate remains as to whether specifically the size of a habitat patch or the density of nests has the greatest effect on nest predation rates. We explored the interactions between landscape context, predator efficiency, and nest survival. Northern bobwhite quail (Colinus virginianus …

Survival And Cause-Specific Mortality Of White-Tailed Deer (Odocoileus Virginianus) Neonates In A Southeastern Kentucky Population, Joseph R. Mcdermott

Theses and Dissertations--Forestry and Natural Resources

Maintaining desired numbers of wildlife species requires an understanding of species-specific population dynamics. For ungulate species such as the white-tailed deer (Odocoileus virginianus), understanding the neonatal survival rate of a population and factors that influence that survival rate, may be two of the most important factors to successful deer management. We examined neonatal survival in an eastern Kentucky population of deer living in relatively low densities (/ km²), with adequate habitat and supposedly poor population growth. Neonates (102) were captured in the summer birth periods of 2014 - 2016 and radio-monitored until the beginning of the …

Mink Predation Of Brown Trout In A Black Hills Stream, Jake Davis, Jerry W. Wilhite, Steven R. Chipps

The Prairie Naturalist

In the early 2000’s, declines in the brown trout (Salmo trutta) fishery in Rapid Creek, South Dakota, caused concern for anglers and fisheries managers. We conducted a radio telemetry study in 2010 and 2011 to identify predation mortality associated with mink, using hatchery-reared (2010) or wild (2011) brown trout. Estimated predation rates by mink (Mustela vison) on radio-tagged brown trout were 30% for hatchery fish and 32% for wild fish. Size frequency analysis revealed that the size distribution of brown trout lost to predation was similar to that of other, radio-tagged brown trout. In both years, a higher proportion of …

Potential Direct And Indirect Effects Of Climate Change On A Shallow Natural Lake Fish Assemblage, Jason J. Breeggemann, Mark A. Kaemingk, Timothy J. Debates, Craig P. Paukert, Jacob R. Krause, Alexander P. Letvin, Tanner M. Stevens, David W. Willis, Steven R. Chipps

School of Natural Resources: Faculty Publications

Much uncertainty exists around how fish communities in shallow lakes will respond to climate change. In this study, we modelled the effects of increased water temperatures on consumption and growth rates of two piscivores (northern pike [Esox lucius] and largemouth bass [Micropterus salmoides]) and examined relative effects of consumption by these predators on two prey species (bluegill [Lepomis macrochirus] and yellow perch [Perca flavescens]). Bioenergetics models were used to simulate the effects of climate change on growth and food consumption using predicted 2040 and 2060 temperatures in a shallow Nebraska Sandhill lake, …

Recolonizing Wolves And Mesopredator Suppression Of Coyotes:Impacts On Pronghorn Population Dynamics, Kim Murray Berger, Mary M. Conner

Wildland Resources Faculty Publications

Food web theory predicts that the loss of large carnivores may contribute toelevated predation rates and, hence, declining prey populations, through the process ofmesopredator release. However, opportunities to test predictions of the mesopredator releasehypothesis are rare, and the extent to which changes in predation rates influence preypopulation dynamics may not be clear due to a lack of demographic information on the preypopulation of interest. We utilized spatial and seasonal heterogeneity in wolf distribution andabundance to evaluate whether mesopredator release of coyotes (Canis latrans), resulting fromthe extirpation of wolves (Canis lupus) throughout much of the United States, contributes tohigh rates of …

Potential For Biocontrol Of Environmental Vibrio Spp. By Predatory Bacteria Bacteriovorax, Patrick Tennis

OES Theses and Dissertations

The scale of predator-prey interactions varies from the iconic (e.g., lions and gazelles) to the microscopic (e.g., protists and bacteria). Bdellovibrio-and-like-organisms (BALOs) are bacteria that prey upon other Gram-negative bacteria, including pathogens. In particular, the halophilic genus Vibrio, many species of which are disease agents, has been shown to be susceptible to attack by BALOs. One motivation of the present research is to assess the potential for biocontrol of Vibrio by Bacteriovorax. This investigation is the first to test the susceptibility of Vibrio strains (n = 26) originating from a variety of geographic locations to predation by …

Does Human Predation Risk Affect Harvest Susceptibility Of White-Tailed Deer During Hunting Season?, Andrew R. Little, Stephen Demarais, Kenneth L. Gee, Stephen L. Webb, Samuel K. Riffell, Joshua A. Gaskamp, Jerrod L. Belant

School of Natural Resources: Faculty Publications

Large carnivores are considered a primary source of mortality for many ungulate populations, but harvest by hunters is the primary means of population management. However, research is needed to evaluate how human predation risk influences observability (a surrogate to harvest susceptibility) of ungulates. We determined how hunting intensity and duration influence observation rates of white-tailed deer (Odocoileus virginianus) and how deer behavior (i.e., movement rate and resource selection) affects observation rates. We sampled 37 adult (≥2 yr) male deer at 2 levels of risk (i.e., low-risk = 1 hunter/101 ha; and high-risk = 1 hunter/30 ha) during 3 …

Determining Impacts Of Mountain Lions On Bighorn Sheep And Other Prey Sources In The Black Hills, Joshua B. Smith

Electronic Theses and Dissertations

From 2009 to 2013, we assessed cougar (Puma concolor) feeding habits and bighorn sheep (Ovis canadensis) population dynamics in the Black Hills, South Dakota. We used Global Positioning System (GPS) telemetry to locate 1,506 cougar feeding events and found deer (Odocoileus spp.; 83%), primarily white-tailed deer (O. virginianus), dominated cougar diets. Overall ungulate kill rate averaged 0.79 ungulates/week (range = 0.13–1.75 ungulates/week), and was significantly higher (P < 0.001) in summer (xˉ = 0.92; SE = 0.06) than in winter (xˉ = 0.62; SE = 0.06). In contrast, biomass consumed was significantly higher (P = 0.033) in winter (xˉ = 8.23 kg/day; SE = 0.96) than in summer (xˉ = 5.45 kg/day; SE = 0.43), primarily as a result of increased scavenging (winter = 0.21 events/week; summer = 0.08 events/week), which represents the highest documented rate for cougar populations studied. We also documented a relatively high rate of chronic wasting disease- (CWD) infected elk in 2 cougar (1 male; 1 female) diets (64%; 95% CI = 50.3–78.3%) and speculate that CWD infection likely increased elk predation risk. Annual lamb survival was 0.02 (SE = 0.01) with pneumonia (36%) and predation (30%) the leading causes of mortality. We found pneumonia and predation were temporally heterogeneous with lambs most susceptible to predation during the first 2–3 weeks of life, while the greatest risk from pneumonia occurred from weeks 4–8. Annual ewe survival was 0.81 (SE = 0.04) with pneumonia (19%) and predation (19%) the leading causes of documented mortality; 48% were unknown. Additionally, we used vaginal implant transmitters (VITs) to assess capture efficiency and document parturition and neonate lamb bed site selection for bighorn sheep. We found successful VITs increased capture efficiency (95%) over unsuccessfully-vitted ewes (81%) and ewes not equipped with VITs (70%). Bighorn ewes selected for rugged terrain at both macro- and microhabitat scales, while at the macrohabitat scale ewes selected for areas that were close to perennial streams on south and west facing slopes and against anthropogenic disturbance. At the microhabitat scale, neonate lambs tended to select for greater cover and against north facing slopes.

Nest Success And Habitat Choice Of Wilson's Plovers In Tom Yawkey Wildlife Center Heritage Preserve, South Carolina, Elizabeth Zinsser

All Theses

Little is known about the reproductive ecology of Wilson's Plover (Charadrius wilsonia). I conducted a study of nest site selection and nest success at a critical breeding area in South Carolina, USA. Data from other coastal nesting birds in the region suggest that a suite of environmental factors including flooding and predation may limit nest success in this region. To assess nest success rates of Wilson's Plovers in an area with limited human disturbance I monitored 72 nests during 2012 and 2013 on South Island and Sand Island located in Tom Yawkey Wildlife Center and Heritage Preserve. I measured environmental …

Cougar Predation Behavior In North-Central Utah, Dustin L. Mitchell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Today’s ability to apply global positioning systems (GPS) collars to wild animals and track their movements, without inadvertently disrupting their daily routine, is a major benefit to wildlife research. Cougars are carnivorous predators that have been identified as being one of several possible causes for recent mule deer population declines throughout the Western United States. Past cougar predation studies have relied on snow tracking, radio-collar tracking, and modeling techniques to estimate cougar prey use and predation rates. These methods rely heavily on weather conditions, logistical availabilities, and broad assumptions, which have led to a wide range of predation rate estimates. …

Review Of The Negative Influences Of Non-Native Salmonids On Native Fish Species, Kelly C. Turek, Mark A. Pegg, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Non-native salmonids are often introduced into areas containing species of concern, yet a comprehensive overview of the short- and long-term consequences of these introductions is lacking in the Great Plains. Several authors have suggested that non-native salmonids negatively influence species of concern. The objective of this paper is to review known interactions between non-native salmonids and native fishes, with a focus on native species of concern. After an extensive search of the literature, it appears that in many cases non-native salmonids do negatively influence species of concern (e.g., reduce abundance and alter behavior) via different mechanisms (e.g., predation and competition). …

Predation, Herbivory, And Parasitism, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.