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Garter Snake (Thamnophis) Natural History: Food Habits And Interspecific Aggression, Michael J. Edgehouse Dec 2008

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, …


A Conceptual Framework For Understanding Effects Of Wildlife Water Developments In The Western United States, Randy T. Larsen Dec 2008

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 …


Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen Dec 2008

Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, …


The Genetics Of Colonization In Two Amphibian Species After The 1980 Eruption Of Mount St. Helens, Kristin Ann Bakkegard Dec 2008

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 …


Sex-Biased Predation On Taricha By A Novel Predator In Annadel State Park, Amber Noelle Brouillette Dec 2008

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 …


On Estimating The Exponent Of Power-Law Frequency Distributions, Ethan P. White, B. J. Enquist, J. L. Green Jan 2008

On Estimating The Exponent Of Power-Law Frequency Distributions, Ethan P. White, B. J. Enquist, J. L. Green

Biology Faculty Publications

Power-law frequency distributions characterize a wide array of natural phenomena. In ecology, biology, and many physical and social sciences, the exponents of these power-laws are estimated to draw inference about the processes underlying the phenomenon, to test theoretical models, and to scale up from local observations to global patterns. Therefore, it is essential that these exponents be estimated accurately. Unfortunately, the binning-based methods traditionally utilized in ecology and other disciplines perform quite poorly. Here we discuss more sophisticated methods for fitting these exponents based on cumulative distribution functions and maximum likelihood estimation. We illustrate their superior performance at estimating known …


Influence Of Pocket Gopher Mounds On Nonnative Plant Establishment In A Shrubsteppe Ecosystem, G. P. Kyle, Andrew Kulmatiski, Karen H. Beard Jan 2008

Influence Of Pocket Gopher Mounds On Nonnative Plant Establishment In A Shrubsteppe Ecosystem, G. P. Kyle, Andrew Kulmatiski, Karen H. Beard

Wildland Resources Faculty Publications

Soil disturbances across a wide range of spatial scales have been found to promote the establishment of invasive plant species. This study addresses whether mounds built by northern pocket gophers (Thomomys talpoides) in the shrubsteppe environment of north central Washington are facilitating plant invasions into native-dominated fields. Research was conducted in native-dominated plant communities adjacent to ex-arable, nonnative-dominated fields. To determine the effect of mounds on plant growth, we recorded new establishment and persistence of all plant species over 2 growing seasons on 10–19 mound and intermound areas in 10 fields. Nonnative plant establishment was not affected by mounds, but …


Quantitative-Genetic Variation In Morphological And Physiological Traits Within A Quaking Aspen (Populus Tremuloides) Population, Megan K. Kanaga, Ronald J. Ryel, Karen E. Mock, Michael E. Pfrender Jan 2008

Quantitative-Genetic Variation In Morphological And Physiological Traits Within A Quaking Aspen (Populus Tremuloides) Population, Megan K. Kanaga, Ronald J. Ryel, Karen E. Mock, Michael E. Pfrender

Wildland Resources Faculty Publications

Genetic diversity within populations is an important component of adaptive evolution, and recent research has demonstrated that genetic variation within plant populations can have important ecological effects. In this study, we investigate quantitative-genetic variation in several traits within a quaking aspen (Populus tremuloides Michx.) population. A common garden experiment was planted with replicates of 13 aspen genotypes collected from wet and dry sites within a population in southern Utah, USA. Ten growth, leaf, physiological, and structural traits were measured. There were significant, heritable phenotypic differences among genotypes in every measured trait and differences in 4 of the 10 traits among …