Life Sciences Commons^™

Sex-Biased Predation On Taricha By A Novel Predator In Annadel State Park, Amber Noelle Brouillette

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Newts of the genus Taricha have long been studied due to the powerful neurotoxin found in their skin. Tetrodotoxin (TTX) acts by blocking receptors in sodium channels, ultimately resulting in death via asphyxiation. The only documented predators of species in this genus have been snakes of the genus Thamnophis. Recently, predation on Taricha in Ledson Marsh in Annadel State Park, Santa Rosa, CA was discovered. Predation was in the form of laceration or evisceration, and tracking of predation from 1998-2008 showed that it was male-biased. Two species of Taricha were found living sympatrically at this location, the California newt …

Predator-Prey Relationships And Spatial Ecology Of Jaguars In The Southern Pantanal, Brazil: Implications For Conservation And Management, Sandra Maria Cintra Cavalcanti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Pantanal wetland of Brazil is an important area for the conservation of jaguars (Panthera onca) and a stronghold for the species. Although our knowledge of jaguar ecology has increased since the first field studies in the mid 1980’s, a detailed study of this cryptic species remains challenging. In the following chapters, we investigated the ecology of jaguars in the southern Pantanal of Brazil. In Chapter II, we examined the foraging ecology of jaguars, documenting predation rates, patterns, and species killed. We found individual jaguars differed in the selection of their prey. There were differences in the proportion …

Estimating Total Phosphorus And Total Suspended Solids Loads From High Frequency Data, Amber Spackman Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Frequently measured turbidity was examined as a surrogate for total phosphorus (TP) and total suspended solids (TSS) loads at two locations in the Little Bear River, Utah, USA. Using regression techniques, equations were developed for TP and TSS as functions of turbidity. The equations accounted for censored data, and additional explanatory variables to represent hydrological conditions were considered for inclusion in the equations. By using the resulting surrogate relationships with high frequency turbidity measurements, high frequency estimates of TP and TSS concentrations were calculated. To examine the effect of sampling frequency, reference loads were determined from the concentration records for …

Phenotypic Plasticity And The Post-Modern Synthesis: Integrating Evo-Devo And Quantitative Genetics In Theoretical And Empirical Studies, Alison G. Scoville

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mainstream evolutionary biology lacks a mature theory of phenotype. Following from the Modern Synthesis, researchers tend to assume an unrealistically simple mapping of genotype to phenotype, or else trust that the complexities of developmental architecture can be adequately captured by measuring trait variances and covariances. In contrast, the growing field of evolutionary developmental biology (evo-devo) explicitly examines the relationship between developmental architecture and evolutionary change, but lacks a rigorous quantitative and predictive framework. In my dissertation, I strive to integrate quantitative genetics and evo-devo, using both theoretical and empirical studies of plasticity. My first paper explores the effect of realistic …

Evolutionary Genetics Of Tetrodotoxin (Ttx) Resistance In Snakes: Tracking A Feeding Adaptation From Populations Through Clades, Chris R. Feldman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the nature of adaptive evolution has been the recent focus of research detailing the genetic basis of adaptation and theoretical work describing the mechanics of adaptive evolution. Nevertheless, key questions regarding the process of adaptive evolution remain. Ultimately, a detailed description of the ecological context, evolutionary history, and genetic basis of adaptations is required to advance our understanding of adaptive evolution. To address some of the contemporary issues surrounding adaptive evolution, I examine phenotypic and genotypic changes in a snake feeding adaptation.

Adaptations can arise through fixation of novel mutations or recruitment of existing variation. Some populations of the …

Garter Snake (Thamnophis) Natural History: Food Habits And Interspecific Aggression, Michael J. Edgehouse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Communication and recognition are closely intertwined and have been well documented in closely related species over the past several decades. These two types of behaviors often will aid in fostering or disrupting coexistence of similar species. Frequently, it is through different diet patterns that similar species will be able to coexist. This study uses data from 1972 through 2006 to demonstrate the diet of Thamnophis sirtalis, T. atratus, T. elegans, and T. couchii throughout their California range of sympatry with Taricha torosa. Additionally, an in depth examination of the diet of T. sirtalis, T. elegans, …

Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant^-1 s^-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO₂ uptake. Diurnal cycles in ethylene synthesis were present in …

Disturbance As Restoration In The Intermountain Sagebrush Steppe: Effects On Non Target Bird Species, Russell Edward Norvell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes in shrubsteppe passerine bird habitat associations in response to disturbance were investigated at multiple temporal and spatial scales. Spatial measures incorporated the effects of area at different ecological scales (nest site, territory, and landscape) to include ecologically meaningful extents. Temporal measures included seasonal and annual effects, and were designed to detect lagged responses should they occur. Local-to-landscape scale effects of mechanical restoration treatments on local extirpation and abundances of nine species indicated most were insensitive to changes in habitat quality, while abundance models showed only broad declines. Changing the availability of nesting habitat on both the attractiveness and quality …

Diets Of Ladybird Beetles (Coleoptera: Coccinellidae) In Utah Alfalfa Fields, Lynette Nicole Davidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aphidophagous lady beetles rely on multiple sources of food in their environment. Alfalfa fields provide both aphids and many alternate foods, such as other arthropod prey, pollen, and fungi. Alfalfa fields (Medicago sativa L.) in Utah have low aphid densities, which may require lady beetles to consume alternative sources of food. Many methods can be used to determine these diets; frass analysis is used here to compare the diets of the introduced species Coccinella septempunctata L. with two native species, C. transversoguttata richardsoni Brown and Hippodamia convergens Guérin-Méneville, that occur in the Utah alfalfa habitat.

In initial laboratory experiments …

Combining Environmental History And Soil Phytolith Analysis At The City Of Rocks National Reserve: Developing New Methods In Historical Ecology, Lesley Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historical ecology is an emerging and interdisciplinary field that seeks to explain the changes in ecosystems over time through a synthesis of information derived from human records and biological data. The methods in historical ecology cover a wide range of temporal and spatial scales. However, methods for the more recent past (about 200 years) are largely limited to the human archive and dendrochronological evidence which can be subject to human bias, limited in spatial extent or not appropriate for non-forested systems. There is a need to explore new methods by which biological data can be used to understand historic vegetation …

Mountain Pine Beetle Fecundity And Offspring Size Differ Among Lodgepole Pine And Whitebark Pine Hosts, Donovan Gross

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitebark pine (Pinus albicaulis Engelmann) is a treeline species in the central Rocky Mountains. Its occupation of high elevations previously protected whitebark pine from long-term mountain pine beetle outbreaks. The mountain pine beetle, however, is currently reaching outbreaks of record magnitude in high-elevation whitebark pine. We used a factorial laboratory experiment to compare mountain pine beetle (Dendroctonus ponderosae Hopkins) life history characteristics between a typical host, lodgepole pine (Pinus contorta Engelmann), and whitebark pine. We tested the effects of natal host and brood host on beetle fecundity, offspring size, and brood sex-ratio. We reared mountain pine beetles …

The Genetics Of Colonization In Two Amphibian Species After The 1980 Eruption Of Mount St. Helens, Kristin Ann Bakkegard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The genetics of colonization is understudied in salamanders but has large conservation implications as new habitats are formed or restored to their previous condition. The 1980 eruption of Mount St. Helens provided a natural experiment to study the genetic effects of a large infrequent environmental disturbance on two species of salamander, Taricha granulosa (Rough-skinned newt) and Ambystoma gracile (Northwestern salamander). Both these species breed in ponds, and are thought to exhibit high breeding site fidelity and low vagility. I designated three treatments based on the effects of the eruption: new ponds (created by the eruption, immigrants only), recovery lakes (in …

Reproductive Tactics Of Aphidophagous Lady Beetles: Comparison Of A Native Species And An Invasive Species That Is Displacing It, Yukie Kajita

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coccinella septempunctata L. (Coleoptera: Coccinellidae) has been introduced to North America in recent decades, raising concerns of adverse impacts on native lady beetles, including the congeneric C. transversoguttata richardsoni (Brown). The central focus of my dissertation is to understand the importance of reproduction, in particular, in promoting invasion of C. septempunctata and its replacement of native lady beetles in alfalfa fields of western North America.

Studies were conducted to compare reproductive tactics of the invasive C. septempunctata and the native C. transversoguttata, by addressing: 1) maximum rate of reproduction of overwintered lady beetles, 2) population dynamics of the invasive …

A Conceptual Framework For Understanding Effects Of Wildlife Water Developments In The Western United States, Randy T. Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Free water can be a limiting factor to wildlife in arid regions of the world. In the western United States, management agencies have installed numerous, expensive wildlife water developments (e.g. catchments, guzzlers, wells) to: 1) increase the distribution or density of target species, 2) influence animal movements, and 3) mitigate for the loss of available free water. Despite over 50 years as an active management practice, water developments have become controversial for several species. We lack an integrated understanding of the ways free water influences animal populations. In particular, we have not meshed understanding of evolutionary adaptations that reduce the …

Reproductive Biology Of The Coyote (Canis Latrans): Integration Of Behavior And Physiology, Debra Anne Carlson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wild Canis species possess a unique suite of reproductive traits including social monogamy, copulatory lock/tie, and biparental care. Females are seasonally monestrous and experience an obligatory pseudopregnancy after spontaneous ovulation. While these characteristics have been ascribed to coyotes, an integrated profile of behavior and physiology has not yet been described. In this study, temporal correlations between steroid hormone levels and socio-sexual mating behaviors were documented, as were changes in vaginal epithelium. Pseudopregnancy was compared to pregnancy by contrasting hormone (progesterone, estradiol, prolactin and relaxin) profiles of unmated females to patterns obtained in alternate years when they bred. Meanwhile, social interactions …

An Investigation Of The Early Life-History Of Brown Trout (Salmo Trutta) And Potential Influences On Invasion Success In The Logan River, Utah, Jeremiah Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to the significant threats posed by nonnative fish species worldwide, it is important to understand how life-history strategies of individual species interact with environmental conditions to explain the success or failure of nonnative fish invasions. Brown trout are prolific invaders, but often exhibit upstream distributional limits in Intermountain West streams, potentially due to a maladaptive reproductive life-history strategy influenced by hydrologic conditions in high-elevation areas. We used redd counts, egg survival experiments, and temperature modeling to investigate the reproductive life-history strategy of brown trout and its potential for success along an elevational stream gradient. We documented brown trout spawning …

Granivores And Restoration: Implications Of Invasion And Considerations Of Context-Dependent Seed Removal, Steven M. Ostoja

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Granivores are important components of sagebrush communities in western North America. These same regions are being altered by the invasion of the exotic annual Bromus tectorum (cheatgrass) that alters physical and biological dynamics in ways that appear to promote its persistence. This research directly relates to the restoration of B. tectorum-dominated systems in two inter-related ways. First, because these landscapes have large quantities of seeds applied during restoration, it is important to determine the major granivore communities in intact sagebrush communities and in nearby cheatgrass-dominated communities. Second, it is important to develop an understanding of patterns of seed harvest …

Ponderosa Pine Mortality And Bark Beetle-Host Dynamics Following Prescribed And Wildland Fires In The Northern Rocky Mountains, Usa, Ryan Stephen Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ponderosa pine delayed mortality, and bark beetle attacks and emergence were monitored on 459 trees for 3 years following one prescribed fire in Idaho and one wildland fire in Montana. Resin flow volume (ml) was measured on 145 fire-injured ponderosa pine 2 and 3 years post-fire. Logistic regression was used to construct two predictive ponderosa pine mortality models, and two predictive bark beetle-attack models. Post-fire delayed tree mortality was greater with the presence of primary bark beetles independent of diameter at breast height (DBH) (cm), and was greater in smaller diameter trees most likely due to direct effects of fire-caused …

Conservation Implications Of Winter-Feeding Policies For Mule Deer In Utah, Chris C. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Policies regulating wildlife winter-feeding programs may have long-term impacts on conservation and future management of both target and non-target species. In 2000, the Utah Wildlife Board, upon reviewing input from a series of public regional meetings, adopted a Utah Big Game Winter-Feeding Policy. The Utah Division of Wildlife Resources used this policy to regulate winter-feeding programs for mule deer in northern Utah, 2001-2005. I monitored the program effects on mule deer biology, activity and migration, and winter browse utilization and productivity.

While feed rations generally compensated for protein and energy deficiencies, they may overlook mineral deficiencies. To determine if mule …