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Full-Text Articles in Life Sciences

You Can Lead A Horse To Water: Mapping Seasonal Water Resources To Predict Wild Horse Movements On Utah Rangelands, David C. Stoner, Eric Thacker, Linden Greenhalgh, Mark Nelson Dec 2023

You Can Lead A Horse To Water: Mapping Seasonal Water Resources To Predict Wild Horse Movements On Utah Rangelands, David C. Stoner, Eric Thacker, Linden Greenhalgh, Mark Nelson

All Current Publications

All wild horse herd management areas in Utah overlap BLM grazing allotments. Although horses and cattle have similar dietary habits, both species rely heavily on predictable water sources during dry periods. The concentration of wildlife and livestock in mesic areas during droughts can become problems for farmers and livestock producers. We aimed to map the annual distribution of temporary surface water across Utah that cattle, horses, and wildlife could use. Herein we analyzed an 18-year record of satellite imagery to create a statewide map of seasonal surface-water availability for agricultural and wildlife management purposes.


Anthropogenic Factors Affecting Common Raven Occurrence And Depredation Of Artificial Nests Within Greater Sage‐Grouse Habitat In Southern Utah, Zoë S. Moffett Aug 2023

Anthropogenic Factors Affecting Common Raven Occurrence And Depredation Of Artificial Nests Within Greater Sage‐Grouse Habitat In Southern Utah, Zoë S. Moffett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain species of wildlife are more generalist and adaptive than others. These species often flourish when supported by human activities that provide additional food and habitat for them. The common raven (Corvus corax; hereafter raven) is one such species; their populations have risen and spread throughout the Intermountain West. As generalist scavengers and predators, ravens have been found to pose a severe threat to several threatened or sensitive species, including the greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse). The purpose of my research was to determine the specific anthropogenic and habitat factors that may increase the threat …


Assessing The Needs Of Utah Dairy Farmers To Inform Extension Programming, Bruce F. Richards, Lendel Narine, Justin Clawson, Kalen Taylor, Jacob Hadfield, Jody Gale Jul 2023

Assessing The Needs Of Utah Dairy Farmers To Inform Extension Programming, Bruce F. Richards, Lendel Narine, Justin Clawson, Kalen Taylor, Jacob Hadfield, Jody Gale

Outcomes and Impact Quarterly

A needs assessment was conducted by the Utah State University Dairy Extension Team to identify the most urgent issues faced by Utah dairy farmers. The assessment found that the top five priority needs were implementing new technology, improving public perception of water use, managing risk, succession planning, and reducing feed costs. The results will guide dairy Extension programming in Utah. Several workshops and events have already been planned to address these needs. Overall, the assessment will help USU Extension provide research-based educational programs to meet the needs of the dairy industry in Utah.


The Impacts Of A Quagga And Zebra Mussel Infestation, Casey Silva Dec 2022

The Impacts Of A Quagga And Zebra Mussel Infestation, Casey Silva

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Invasive species issues have been on the rise in the United States for decades. These organisms can disrupt the natural flow of an ecosystem and overtake native species, altering an environment as a whole. The introduction of the zebra mussel (Dreissena polymorpha) in 1988, followed by the quagga mussel (Dreissena rostriformis) in 1989 is arguably the most prolific aquatic infestation the nation is currently up against (Hoddle, 2022). Beginning in the Great Lakes, both quagga and zebra mussels quickly spread their infestations through the Midwest and the East coast. The potential invasion of these species across …


Forest Grouse Ecology And Management In The Bear River Range Northern Utah, Skyler Y. Farnsworth May 2020

Forest Grouse Ecology And Management In The Bear River Range Northern Utah, Skyler Y. Farnsworth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To better manage dusky grouse (Dendragapus obscurus) and ruffed grouse (Bonasa umbellus), hereafter forest grouse, managers require better information on forest grouse population status and habitat selection. To address this need, from 2015-2017, I conducted research on a sympatric populations inhabiting the Bear River Range of northern Utah to develop a breeding survey protocol, assess habitat selection, evaluate dusky grouse response to livestock grazing, and determine hunter harvest rates.

The breeding census protocol that I developed compared listening intervals with and without electronic playback calls at designated survey stop locations. Using digital mapping software, I plotted …


Predicting Black Bear Activity At Backcountry Campsites In Bryce Canyon National Park, Utah, Wesley G. Larson, Tom Smith Jan 2019

Predicting Black Bear Activity At Backcountry Campsites In Bryce Canyon National Park, Utah, Wesley G. Larson, Tom Smith

Human–Wildlife Interactions

Developing the capacity to predict black bear (Ursus americanus; bear) activity in a diversity of habitats will help conserve bear populations and their habitats and minimize human–bear conflicts. This capacity will be particularly important in areas that provide bear habitat and offer backcountry hiking and camping experiences. Bryce Canyon National Park (BRCA), located on the edge of the Paunsaugunt Plateau in southern Utah, USA, provides important bear habitat and offers visitors 12 backcountry campsites. To effectively manage these areas to minimize human–bear conflicts, park managers will need better information about black bear use of these campsites and other …


The Three Creeks Allotment Consolidation: Changing Western Federal Grazing Paradigms, Taylor Payne Jan 2018

The Three Creeks Allotment Consolidation: Changing Western Federal Grazing Paradigms, Taylor Payne

Human–Wildlife Interactions

The federal government owns approximately 47% of all land in the western United States. In the state of Utah, about 64% of the land base is managed by the federal Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The government has historically issued permits to owners of private lands to allow the owners to graze their livestock on public lands. The permits (allotments) are generally of 10-year duration and allow for an annual season of use. In some cases, continued and repeated historical annual grazing practices may not be ideal for permit holders and their communities nor …


Influence Of Transmission Line Construction On Winter Sage-Grouse Habitat Use In Southern Utah, Erica P. Hansen, A. Cheyenne Stewart, S. Nicole Frey Jan 2016

Influence Of Transmission Line Construction On Winter Sage-Grouse Habitat Use In Southern Utah, Erica P. Hansen, A. Cheyenne Stewart, S. Nicole Frey

Human–Wildlife Interactions

The construction and operation of electric power transmission lines (“power lines”) and their associated infrastructure has been identified as a conservation threat to the greater sage-grouse (Centrocercus urophasianus; sage-grouse). The conservation buff er zones recommended by state and federal agencies to avoid potential impacts on breeding populations diff er because information regarding the effects of power lines on sage-grouse is lacking. Little information is available regarding sage-grouse responses to power lines placed in winter habitat. Hence, we evaluated sage-grouse habitat use before and after construction of the Sigurd-Red Butte (SRB) 345-kilovolt (kV) transmission line in winter habitat. The …


Ecology Of Greater Sage-Grouse Populations Inhabiting The Northwestern Wyoming Basin, Casey J. Cardinal, Terry A. Messmer Jan 2016

Ecology Of Greater Sage-Grouse Populations Inhabiting The Northwestern Wyoming Basin, Casey J. Cardinal, Terry A. Messmer

Human–Wildlife Interactions

Range-wide population declines of greater sage-grouse (Centrocercus urophasianus; sage-grouse) have been largely attributed to habitat loss and fragmentation. However, the specific conservation threats affecting the ecology of sage-grouse populations may diff er by region. Although the status of the Bear Lake Plateau and Valley (BLPV) sagegrouse populations in the Wyoming Basin has been monitored using male lek counts since the 1960s, little was known about their ecology, seasonal movements, and habitat use patterns. From 2010–2012, we radio-marked 153 sage-grouse (59 females and 94 males) with very high frequency necklace-style radio-collars throughout the BLPV study area, which encompassed parts …


An Analysis Of Human–Black Bear Conflict In Utah, Julie Ann Miller, Tom S. Smith, Janene Auger, Hal Black, Loreen Allphin Jan 2016

An Analysis Of Human–Black Bear Conflict In Utah, Julie Ann Miller, Tom S. Smith, Janene Auger, Hal Black, Loreen Allphin

Human–Wildlife Interactions

Conflict between black bears (Ursus americanus) and humans has occurred in Utah, but the records are largely incomplete. To document these events, the Utah Division of Wildlife Resources initiated a black bear sightings and encounters database in 2003, and we updated it. From 2003–2013, there were 224 recorded events, with 10 attacks, 208 property damages, and 6 vehicle collisions. Most events took place at campsites (40%). The most common season for events was summer (78%). Most conflict occurred at night. The number of events has not increased over the last 10 years, with no significant relationship between the …


Assessing Vehicle-Related Mortality Of Mule Deer In Utah, Daniel D. Olson May 2013

Assessing Vehicle-Related Mortality Of Mule Deer In Utah, Daniel D. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Roads are essential in modern societies, but as populations grow and traffic volumes rise, roads will continue to be built and expanded. As a result, the effects that roads have on wildlife will likely intensify, making it imperative that managers understand those effects so mitigation can be directed accordingly. In Utah, considerable areas of mule deer (Odocoileus hemionus) habitat have been bisected by roads. Mule deer are commonly involved in vehicle collisions and there is concern that roads and vehicle traffic are impacting populations. This project was conducted to determine the number and demographic effects of deer-vehicle collisions, …


Winter Ecology Of Waterfowl On The Great Salt Lake, Utah, Josh L. Vest May 2013

Winter Ecology Of Waterfowl On The Great Salt Lake, Utah, Josh L. Vest

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I designed a suite of studies in coordination with Utah Division of Wildlife Resources (UDWR) to evaluate waterfowl use of the GSL in winter and ecological aspects associated with GSL use. These studies provided insight into key information gaps previously identified by UDWR regarding management of GSL resources. Population surveys indicated total duck abundance was low when GSL surface elevations were low and wetland resources diminished because of persistent drought in the system. Also, ducks appear to use hypersaline parts of GSL more when freshwater habitats are limited from either drought or ice conditions. Common goldeneye, northern shoveler, and green-winged …


Habitat Characteristics And Occupancy Rates Of Lewis's Woodpecker In Aspen, Amy M. Vande Voort May 2011

Habitat Characteristics And Occupancy Rates Of Lewis's Woodpecker In Aspen, Amy M. Vande Voort

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lewis‘ woodpeckers (Melanerpes lewis) are generally associated with open ponderosa pine (Pinus ponderosa), open riparian, and burned pine habitats in the West; however, this species has recently been found to nest in aspen (Populus tremuloides) stands in Utah. This study describes the habitat characteristics of Lewis‘ woodpecker nest sites in aspen and investigates how well aspen stand characteristics predict Lewis‘ woodpecker occupancy. I surveyed for Lewis‘ woodpeckers at previously occupied nesting locations in aspen and took habitat measurements at nest sites. In addition, nest-centered Forest Inventory and Analysis (FIA)-type plots provided stand-level habitat characteristics. I used logistic regression to …


Application Of Habitat And Occupancy Modeling To A Wood Duck Next Box Program, Jason D. Carlisle May 2011

Application Of Habitat And Occupancy Modeling To A Wood Duck Next Box Program, Jason D. Carlisle

Undergraduate Honors Capstone Projects

Programs to augment wood duck (Aix sponsa) nesting habitat by providing artificial nest boxes are commonly implemented. In northern Utah, where such programs are relatively new, I proposed a method to identify sites suitable for deployment of next boxes through a combination of habitat and occupancy modeling using site-specific, biotic, and abiotic, data collected from 105 next boxes over one nesting season in Cache County, Utah. An inductive habitat model was first developed which identified possibly suitable habitat (8.74% of county) based on proximity to hydrologic features. Next, based on comparing competing single-species, single-season, occupancy models using a modified Akaike's …


Greater Sage-Grouse Response To Sagebrush Reduction Treatments In Rich County, Utah, Roger Blair Stringham May 2010

Greater Sage-Grouse Response To Sagebrush Reduction Treatments In Rich County, Utah, Roger Blair Stringham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Management of greater sage-grouse (Centrocercus urophasianus) in the west has changed over the last several decades in response to environmental and anthropogenic causes. Many land and wildlife management agencies have begun manipulating sagebrush with herbicides, machinery, and fire. The intent of these manipulations (treatments) is to reduce sagebrush canopy cover and increase the density of grass and forb species, thus providing higher quality sage-grouse brood-rearing habitat. However, monitoring of sage-grouse response to such manipulations has often been lacking or non-existent. The objective of our study was to determine the response of sage-grouse to sagebrush reduction treatments that have …


The Influence Of Landscape And Weather On Foraging By Olfactory Meso-Predators In Utah, Rebekah E. Dritz May 2010

The Influence Of Landscape And Weather On Foraging By Olfactory Meso-Predators In Utah, Rebekah E. Dritz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Predation by olfactory meso-predators has a large impact on avian nest success, particularly for ground-nesting waterfowl. Olfactory predators rely on odors to locate their prey. Weather conditions (e.g. wind speed, humidity, and temperature), vegetation, and landscape features affect the dissipation rate of odors and could affect the foraging efficiency of olfactory predators. I conducted 2 studies to determine if weather and landscape impact predator foraging ability and behavior: a predator survey study and an artificial nest study. The objective of the predator survey was to investigate how landscape and weather conditions interact to influence the distribution of olfactory meso-predators [e.g. …


Effects Of Waterfowl Hunting On Raccoon Movements, Shandra Nicole Frey, Michael R. Conover Jan 2010

Effects Of Waterfowl Hunting On Raccoon Movements, Shandra Nicole Frey, Michael R. Conover

Human–Wildlife Interactions

Nontarget wildlife may react to hunters with avoidance, ambivalence, or attraction, depending upon the frequency of contact and the consequences of past contacts. We studied raccoons (Procyon lotor) located within the Bear River Migratory Bird Refuge, Utah, before and during waterfowl hunting seasons to assess changes in the size of their distributions, locations, and travel distances. Raccoon distribution size did not change with the onset of hunting. Once hunting began, raccoons were located more frequently in areas with lower densities of hunters and less frequently in areas with higher densities of hunters. Raccoons also responded to the presence …


Assessment Of Costs Associated With Deer–Vehicle Collisions: Human Death And Injury, Vehicle Damage, And Deer Loss, John A. Bissonette, Christine A. Kassar, Lawrence J. Cook Jan 2008

Assessment Of Costs Associated With Deer–Vehicle Collisions: Human Death And Injury, Vehicle Damage, And Deer Loss, John A. Bissonette, Christine A. Kassar, Lawrence J. Cook

Human–Wildlife Interactions

Collisions between large vertebrates and vehicles along roadways are an increasing concern, not only because of ecological consequences, but also because of associated economic and social costs. We used a large-scale, long-term data set comprising several databases from Utah to summarize and analyze these costs. The overall cost for 13,020 collisions from 1996 to 2001 in Utah was approximately $45,175,454, resulting in an estimated average per year cost of about $7,529,242 and a mean collision cost of $3,470. These figures include human fatality costs of $24 million (53% of total costs); vehicle damage costs of $18 million (39%); loss of …


Factors Influencing Epiphytic Lichen Communities In Aspen-Associated Forests Of The Bear River Range, Idaho And Utah, Paul C. Rogers May 2007

Factors Influencing Epiphytic Lichen Communities In Aspen-Associated Forests Of The Bear River Range, Idaho And Utah, Paul C. Rogers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing habitat, thereby threatening their long-term local and regional viability. Though lichens have a rich history as air pollution indicators, I believe that they may also be useful as a metric of community diversity associated with habitat change. To date, few studies have specifically examined the status of aspen's epiphytic lichen …


Utah Prairie Dog Habitat Evaluation Guide, Natural Resources Conservation Service, Environmental Defense Jan 2007

Utah Prairie Dog Habitat Evaluation Guide, Natural Resources Conservation Service, Environmental Defense

All U.S. Government Documents (Utah Regional Depository)

The Utah prairie dog (Cynomys parvidens) (UPD) is listed as a threatened species under the Endangered Species Act (ESA) and exists only in southwestern Utah. UPD numbers and range have declined dramatically since settlement of Utah because of conversion of rangeland to cropland, urban development, fire suppression, improper grazing, drought, and introduced sylvatic plague (Yersina pestis). As of this writing, approximately 75% of all Utah prairie dogs inhabit private lands. This fact highlights the need to encourage farmers and ranchers to manage UPD habitat on their property in order to move the species closer to recovery. This guide provides technical …


Salinity Controls Phytoplankton Response To Nutrient Enrichment In The Great Salt Lake, Utah, Usa, Amy M. Marcarelli, Wayne A. Wurtsbaugh, O. Griset Jan 2006

Salinity Controls Phytoplankton Response To Nutrient Enrichment In The Great Salt Lake, Utah, Usa, Amy M. Marcarelli, Wayne A. Wurtsbaugh, O. Griset

Watershed Sciences Faculty Publications

To examine how salinity and nutrient supply interact to control phytoplankton community composition, nutrient limitation, and dinitrogen (N2) fixation rates in the Great Salt Lake (Utah, USA), we conducted a series of bioassay experiments with plankton from both Gilbert Bay, where salinities are near 160 g·L–1, and Farmington Bay, where salinities range from 10 to 90 g·L–1. Six-day nutrient addition bioassay experiments showed that the extant phyto plankton communities in both bays were limited by nitrogen (N). However, in 28- to 30-day factorial bioassay experiments in which both salinities and nutrient supply were manipulated, phosphorus stimulated chlorophyll a as much …


Wildlife-Vehicle Collisions In Utah: An Analysis Of Wildlife Road Mortality Hotspots, Economic Impacts And Implications For Mitigation And Management, Christine A. Kassar May 2005

Wildlife-Vehicle Collisions In Utah: An Analysis Of Wildlife Road Mortality Hotspots, Economic Impacts And Implications For Mitigation And Management, Christine A. Kassar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the US, the roaded landscape has had serious ecological effects. We studied wildlife-vehicle collisions occurring on the 248 state routes in Utah from 1992 to 2002. We tracked trends and patterns in deer-vehicle collisions, evaluated all routes for frequency of deer kills, and identified "hotspots" (segments of road with high concentrations of collisions per mile). We found pronounced patterns: e.g., 61.15% of all collisions occurred on only 10 routes. We studied the effects of posted speed limit and annual average daily traffic flow and found that no relationship existed between traffic volume and/or posted speed limit and the number …


Fall 1998 Raptor Migrations Study In The Wellsville Mountains Of Northern Utah, United States Department Of Agriculture, Forest Service Jan 1999

Fall 1998 Raptor Migrations Study In The Wellsville Mountains Of Northern Utah, United States Department Of Agriculture, Forest Service

Elusive Documents

The Wellsville Mountains raptor migration study in northern Utah is an ongoing effort to monitor longterm trends in populations of raptors using this northern Rocky Mountain migratory flyway. Raptors feed atop food pyramids, inhabit most ecosystems, occupy large home ranges, and are sensitive to environmental contamination and other human disturbances. Therefore, they serve as important biological indicators of ecosystem health (Cade et al. 1988; Bednarz et al. 1990a; Bildstein and Zalles 1995). For example, long-term migration counts in the eastern United States documented declines in several raptor species and helped us understand the deleterious effects of organochlorine pesticides (Spofford 1969, …


Endangered And Threatened Animals Of Utah, Utah State University Extension Jan 1998

Endangered And Threatened Animals Of Utah, Utah State University Extension

All Archived Publications

No abstract provided.


Physical Factors Influencing Survival To Emergence And Time Of Emergence Of Shoreslope-Spawned Kokanee Salmon In Flaming Gorge Reservoir, Utah-Wyoming, Randall J. Jeric May 1996

Physical Factors Influencing Survival To Emergence And Time Of Emergence Of Shoreslope-Spawned Kokanee Salmon In Flaming Gorge Reservoir, Utah-Wyoming, Randall J. Jeric

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I used incubation baskets containing viable eggs and spawning substrate to estimate the survival to emergence and time of emergence of kokanee salmon Oncorhynchus nerka at depths to 20 m in Flaming Gorge Reservoir, Utah-Wyoming. Traps on the incubation baskets captured fry emerging from a known quantity of eggs. Water drawn into a syringe from an intragravel pipe buried near each incubation basket was used to determine intragravel dissolved oxygen concentrations throughout the intragravel period. Water from control baskets without eggs did not have significantly greater dissolved oxygen concentrations than adjacent water. A jar associated with each incubation basket collected …


Assessment Of Kokanee Salmon, Oncorhynchus Nerka, Genetic Stocks In Flaming Gorge Reservoir, Utah-Wyoming, Michael F. Canning May 1996

Assessment Of Kokanee Salmon, Oncorhynchus Nerka, Genetic Stocks In Flaming Gorge Reservoir, Utah-Wyoming, Michael F. Canning

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I investigated the relative abundance, spatial distributions, return to the creel, and growth rates of two genetic stocks of kokanee salmon, Oncorhynchus nerka, in Flaming Gorge Reservoir, Utah-Wyoming. The two genetic stocks consist of fish from the two major spawning populations of kokanee in the reservoir. One population, Shore Spawners, spawns along the eastern shoreline of the Open Hills area of the reservoir. The other population, Sheep Creek, spawns in Sheep Creek, a tributary located in the Canyon area of the reservoir.

Mitochondrial DNA of kokanee from each population was analyzed to determine haplotype differences between stocks. These haplotype …


Effects Of Daphnia Availability On Growth And Food Consumption Of Rainbow Trout In Two Utah Reservoirs, R. Tabor, Chris Luecke, Wayne A. Wurtsbaugh Jan 1996

Effects Of Daphnia Availability On Growth And Food Consumption Of Rainbow Trout In Two Utah Reservoirs, R. Tabor, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We monitored the diet and growth of stocked rainbow trout Oncorhynchus mykiss in two Utah reservoirs during 1986 and 1989–1990. For the first month after stocking, juvenile rainbow trout in both reservoirs fed extensively on large Daphnia spp. In East Canyon Reservoir where Daphnia were abundant, this pattern continued throughout the summer, fall, and winter. Growth of rainbow trout in East Canyon Reservoir was generally good throughout 1989–1990. In Causey Reservoir, where Daphnia were less abundant and smaller, rainbow trout fed progressively less on smaller Daphnia throughout the summer, fall, and winter, while other prey items (snails, aquatic insects, and …


Strutting Sounds And Strutting Posturing Of Two Utah Sage Grouse Populations, United States Department Of Agriculture, Forest Service Jan 1995

Strutting Sounds And Strutting Posturing Of Two Utah Sage Grouse Populations, United States Department Of Agriculture, Forest Service

Wildlife Conservation and Management

Sound and video tape recordings and still pictures were taken of two populations of strutting male sage grouse (Centrocercus urophasianus). The two populations studied were from the Strawberry Valley and Parker Mountains. Sixteen elements of sounds were identified in the strutting sequence. These elements were the same for both populations. Video tape and still picture analysis revealed that both populations were similar in posturing during the strutting sequence. We concluded that the Parker Mountains sage grouse population is suitable in terms of breeding display behavior to augment the Strawberry Valley population. Sexual compatibility would need to be determined in future …


Investigations Of Forage Fish And Lake Trout Salvelinus Namaycush Interactions In Flaming Gorge Reservoir, Wyoming-Utah, Daniel L. Yule Jan 1992

Investigations Of Forage Fish And Lake Trout Salvelinus Namaycush Interactions In Flaming Gorge Reservoir, Wyoming-Utah, Daniel L. Yule

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I investigated the interaction of lake trout (Salvelinus namaycush) and their dominant forage fish populations, Utah chub (Gila atraria) and kokanee salmon (Oncorhynchus nerka), in Flaming Gorge Reservoir, Wyoming-Utah. Through bioenergetics modeling, I quantified the consumption dynamics of the lake trout population. From hydroacoustics analyses, I quantified the density and biomass of the two dominant forage fish populations.

In Chapter II, I report the results of the energetics analysis. The objective of this chapter was to understand the role of lake trout predation in recent changes in fish assemblage structure of the reservoir. Through …


Nitrogen And Energy Budgets Of Production Ewes On Summer Range In Southwestern Utah, John W. Halpop May 1988

Nitrogen And Energy Budgets Of Production Ewes On Summer Range In Southwestern Utah, John W. Halpop

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen (N) and energy budgets for free-roaming ewes were quantified on mountain summer range in southwestern Utah in 1986 and 1987. Diet quality (%N), in vitro organic matter digestibility (IVOMD), and energy were estimated with the use of five esophageally fistulated ewes. Excretion rates of N and energy to feces and urine were measured by total collection from five nonfistualted ewes.

Total intake N(gN/(MBW*d-1) tracked intraseasonal changes of dietary N percent but was apparently buffered by fluctuations in dry matter intake. In each year, total urine N was closely related to dietary N concentration, r2=0.97 (1986) …