Life Sciences Commons^™

Intraspecific Variation In Prey Susceptibility Mediates The Consumptive Effect Of Predation: A Case Study Of Yellowstone Elk And Wolves, Lacy M. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The reintroduction of wolves (Canis lupus) to Yellowstone National Park starting in 1995 is an important case study for understanding the consequences of predation on a prey population. Simulation studies conducted prior to and shortly after wolf reintroduction predicted that wolf predation of elk (Cervus canadensis) would have a modest influence on elk abundance. Predation of elk by wolves has been well documented and elk have remained the primary prey for wolves despite a decline in elk abundance. I used two quantitative approaches to estimate the influence of wolf predation on adult female elk survival and …

Influence Of Environmental Variables On Survival Rates Of Pronghorn (Antilocapra Americana) Neonates Across Idaho, Brett R. Panting

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was completed to better understand pronghorn antelope (Antilocapra americana) populations found throughout Idaho. Antelope were studied in three separate and distinct study areas. The Big Desert, Camas Prairie, and Little Lost and Pahsimeroi valleys were all selected as study sites. Idaho Department of Fish and Game (IDFG) is concerned with current pronghorn populations found throughout Idaho. Pronghorn are a valued big game species found in Idaho. Increasing pronghorn populations in Idaho is a focus of IDFG.

We captured and VHF-collared pronghorn fawns found in our three study areas. Fawns were monitored daily with telemetry equipment for …

Efficacy Of Translocation As A Management Tool For Urban Mule Deer In Utah, Channing R. Howard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An increase in urbanization in the United States has led to an increase in human-wildlife interactions with deer (Odocoileus spp.) which have been able to adapt and thrive in these urban environments. In Utah, urbanization has occurred along the Wasatch Front which was once traditional mule deer (Odocoileus hemionus) winter range habitat. This urban expansion coupled with an increasing use of these urban areas by mule deer, have led to increasing conflicts with deer. Overabundant urban deer have led to increased concerns over safety from deer-vehicle collisions, and damage to personal property including gardens and landscaping. …

Comparative Ecology Of Narrowly Sympatric Horned Lizards Under Variable Climatic Conditions, Kevin V. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We studied the Flat-tailed Horned Lizard, Phrynosoma mcallii, and the Sonoran Horned Lizard, P. goodei, in an area of narrow sympatry near Yuma, Arizona, and found they overlapped broadly in use of available food resources, body size, and growth rates. We compared diet (Chapter 2), growth and reproduction (Chapter 3), and survivorship (Chapter 4) of P. mcallii and P. goodei during two years of drought followed by a year of higher-than-average rainfall. We predicted that P. mcallii would be more tolerant of drought conditions than its congener, since P. mcalliiis found only in an extremely arid region while …

Reproductive Allocation And Survival In Grasshoppers: Effects Of Resource Availability, Grasshopper Density, And Parasitism, David Heath Branson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major challenge in ecology is to understand intraspecific variation in life histories. Variation in resource availability can lead to differences in reproductive allocation and life histories. Grasshoppers are a good organism for the study of variation in life histories, since they exhibit life history plasticity in response to biotic and environmental factors. An optimality model for grasshoppers was developed that predicts optimal total allocation to reproduction and optimal effort-per-offspring as functions of resource availability and mortality. Relative allocation to reproduction is predicted to increase with resource availability, while relative allocation to survival declines. A resource-based trade-off between egg size …

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 …

Effect Of Spring Grazing By Cattle On Growth And Survival Of Shrub Seedlings Interplanted In Crested Wheatgrass, Lynn M. Mcconville

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A short duration-high intensity grazing trial was conducted in spring of 1985 to determine whether shrub establishment in crested wheatgrass pastures could be enhanced through spring grazing by cattle, or by fertilization of shrub seedlings. Data was collected on diet selection by cattle during spring grazing, and on subsequent shrub growth and survival. Shrubs studied were transplants of sagebrush, Artemisia tridentata, fourwing saltbush, Atriplex canescens, bitterbrush, Purshia tridentata, and one year old bitterbrush seedlings.

Cattle did not browse sagebrush or fourwing saltbush transplants, but utilization of bitterbrush transplants and seedlings averaged 15 and 42 percent, respectively. Shrub …