Llamas (Lama glama) appear to have predisposing anatomical features for developing
otitis media such as a long and narrow external acoustic meatus and a trabecular
tympanic bulla. However, there is limited information available about the morphology of
the ear in this species. The aim of this study was to evaluate...
Suspensory apparatus breakdown and hyperextension of the metacarpophalangeal and metatarsophalangeal (fetlock) joints is a common condition in the llama and has been observed in llamas of all ages. Llama breeders refer to the condition as "down in the pasterns" or "down in the fetlocks." The condition can result in debilitating...
Managing rangelands with livestock grazing is a tool that can be applied to obtain vegetation management objectives. Animals utilize available resources, which vary in quantity and quality, across the landscape. Their movements are adjusted to the spatial and temporal heterogeneity of resource distribution. Controlling livestock distribution is fundamental to economically...
The known distribution of beluga whales ranges from sub-Arctic to Arctic waters where they migrate in pods in response to environmental factors such as the presence of sea ice and prey. This study uses bivariate and multivariate analysis techniques to measure how environmental covariates are associated with the spatial-temporal distribution...
Plethodontid salamanders have served as an informative vertebrate system for studying the role of chemical signals in facilitating social and reproductive behaviors. Individuals produce complex mixtures of chemicals from multiple glandular regions. In total, these secretions convey a wide variety of information, and are important for numerous inter- and intraspecific...
This thesis examines notions of social unintelligibility produced within queer spaces in two primary texts: Justin Torres' We the Animals and Mario Bellatín's Beauty Salon. Chapter One discusses the racial and queer marginalization of the unnamed narrator and explores his turn towards an "animal language" in his moment of exposure...
Cyprinid herpesvirus 3 (CyHV-3), commonly known as koi herpesvirus (KHV), is a member of the Alloherpesviridae and is a deadly pathogen for koi and common carp, Cyprinus carpio. It causes severe gill necrosis and nephritis, dermal ulceration and hemorrhage, and mass mortality of up to 100% of affected fish. Fish...
Patterns of nest attendance behavior by breeding birds represent a parent-offspring trade-off in which adults balance self-maintenance with parental care decisions.
Incubation, in particular, is of interest because adults must provide an environment
suitable for embryonic development through nest-building and contact-incubation.
We evaluated how adult incubation constancy and nest visitation...
Postcopulatory sexual selection—sperm competition and cryptic female choice—has become a major area of research over the past 40 years. Within this field there are many outstanding questions at every level of analysis, from proximate to ultimate. The fitness consequences for both sexes in the period after copulation and before fertilization...
I monitored demography, movement, and reproductive behavior of gray-tailed voles, Microtus canicaudus, in experimental habitat patches with and without corridors. I tested the hypotheses that reproductive rate, juvenile recruitment, and population size and growth rate would be affected negatively by immigrants that were introduced to resident groups (+ male and...
Index counts for the Pacific Coast race of the band-tailed pigeon (Columba fasciata monilis) have declined by -2% per year since survey efforts began in the 1950's and 60's. Mineral sites, important resources with high ion concentrations, are regularly visited by band-tailed pigeons which nest in surrounding forest lands. I...
Three experiments were conducted in broiler hens to study the influence of dietary n-3 polyunsaturated fatty acids (PUFA) on egg quality, antioxidant status in progeny, and eicosanoid production in tissue. The objective of experiment 1 was to determine the effect of hen age and dietary n-3 PUFA on egg quality...
Commercial hog diets in the United States commonly contain lipid sources high in polyunsaturated fatty acids, most notably linoleic acid (18:2). This may result in greater deposits of linoleic acid in pork adipose tissue, contributing to an increased potential for lipid oxidation, high n-6/n-3 fatty acid ratio and increased fat...
There are more than 87,000 chemicals in current use with little to no toxicity information available. Assessing such a large number of chemicals using traditional methods would take an unreasonable amount of time and money, and require the use a large number of animals. The incorporation of high-throughput in vivo...
Two studies were conducted to evaluate the influence of supplement composition on intake and digestibility of a low-quality (< 6% CP), cool-season forage, as well as cow performance. Treatments included a non-supplemented control (CON), corn (approximately 8% CP), corn and urea (LU = corn + 0.09 mg/kg BW urea, approximately...
Chemoreception is one of the dominant sensory modalities for many species of salamanders (reviewed in Chapter 2). At least seven of the ten currently recognized salamander families are known to respond to some sort of chemical cue. These responses are as varied as delaying hatching, seeking refuge, or initiating aggressive...
Island systems and species are susceptible to extinction because of their small population size and an ecological naiveté from an evolutionary past lacking strong competition and predation. For example, only one-fifth of the world’s bird species occur on islands, yet more than 90% of the avian extinctions witnessed during historic...
I studied sexual segregation in mule deer (Odocoileus
hemionus) and white-tailed deer (Q. virginianus) in
different environments and at different population
densities to test the hypothesis that sexual segregation
occurs in ungulates as the result of different
reproductive strategies; females select habitat and behave
in manners primarily designed to promote...
The mouth of the Columbia River (MCR) is an intersection of more than a river and ocean, but also multiple economically valuable activities including dredging to maintain a deep draft shipping channel and an active Dungeness crab (Metacarcinus magister) fishery. More than three million cubic meters of sediment are annually...
Global Positioning System (GPS) and Geographic Information System (GIS) technologies were employed to evaluate cattle occupancy of three landscape attributes on three different grazing allotments administered by the Wallowa Whitman National Forest in Northeast Oregon. Topographic characteristics of slope; 0-4%, 4-12%, 12-35% and >35% were evaluated as well as north...
The marine environment is under increasing pressure from human activities worldwide, particularly in coastal waters, creating a need to better understand fine-scale distributions of highly mobile species that occur in the area, as they are frequently most threatened. Harbor porpoise (Phocoena phocoena) occur frequently in Oregon’s nearshore habitat, but due...
Laboratories around the world are using the zebrafish model for biomedical research and conducting investigations using morphological, physiological, behavioral, and genomic endpoints. All assays provide information, but physiological and behavioral endpoints or phenotypes are a fast way to understand how an animal is responding to its environment. We investigate the...
Although short-tailed weasels (Mustela erminea) are important predators of small mammals, little is known about their space use, habitat selection, or vulnerability to predation in North America. To evaluate the effects of forest management and social structure on home range size and habitat selection of short-tailed weasels, I conducted a...
Evidence for reduced reproductive success (RS) of wild spawning hatchery-reared fish invites serious consideration with regard to the detrimental effects on subsequent generations of wild populations. Mate choice was evaluated as a potential mechanism contributing to these observed RS differences using a previous pedigree of wild spawning hatchery-reared and wild...
This thesis focuses on the nesting ecology and marine space use of Marbled Murrelets (Brachyramphus marmoratus) during the 2007 and 2008 nesting seasons in and around Port Snettisham, a remote mainland fjord in Southeast Alaska. Marbled Murrelets (murrelets) are a declining species throughout most of their range, and their conservation...
The 100 North Pacific rockfish species in the genus Sebastes are highly diverse. Rockfishes fertilize their eggs internally and release swimming larvae. Complex courting behaviors may allow female rockfish to be selective about their mates and may promote and maintain speciation. In this study, I applied genetic techniques to survey...
The Warm Springs Reservation is located in central Oregon. Livestock production consists of beef (commercial with an Angus, Horned Hereford base) and roping (Corriente and Longhorn) cattle and horses that forage most of the year on the open range within reservation boundaries. Forage consists of annual and perennial grasses and...
The first objective of this study was to quantify the intensity of space use of 70 juvenile (12-26 months old) Steller sea lions (SSLs) from the western Distinct Population Segment (DPS) in the Kenai Fjord(KF)/Prince William Sound (PWS) region of Alaska as derived from externally attached ARGOS satellite transmitter tags....
Developing accurate predictive distribution models requires adequately representing relevant spatial and temporal scales, as these scales are ultimately reflective of the relationships between distributions and influential environmental conditions. In this research, we considered both spatial and temporal scale and the influence each has on predicting broad-scale distributions of two disparate...
The effects of Marine protected areas (MPAs) on adult fish populations depend on the degree of protection provided, which is partly a function of MPA size and the spatial extent of fish movements. The Redfish Rocks Marine Reserve (RRMR) and MPA, located on the south coast of Oregon near Port...
Efficient foraging strategies result in a predator spatially overlapping with its prey, foraging in the most profitable patches, and minimizing the time transiting between patches. Previous studies investigating baleen whale foraging strategies have generally focused on investigating spatial overlap with prey patches, patch profitability or movement within feeding grounds. The...
Concentration ratios are used to determine the transfer of nuclides from soil to biota to fauna. Some nuclides have limited associated data though, this has not prevented predictions from being performed at sites without associated data. These ratios are site specific and are not fully applicable when applied to other...
One second GPS collars were deployed on cattle in three different pastures at three separate times during the year. In each riparian pasture the vegetative communities and stream bank edge were digitally mapped using low elevation aerial photographs and checked in the field for accuracy. A 5 m buffer zone...
We studied the distribution and habitat selection differences between
Spanish breed (Corriente and Longhorn mix) and British breed cattle (Angus,
Hereford). This study was located on the Zumwalt prairie during the spring and
fall and along the Imnaha river for the winter. Each trial ran for two weeks and in...
With continual and worldwide human population growth, our impact on the natural environment expands and intensifies every day. We consume natural resources, burn fossil fuels, and release toxic compounds into the air, water, and earth. We build roads that fragment the landscape, construct new settlements, and develop agricultural lands in...
Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then...
Spatial variation in the diet of the northern spotted owl (Strix occidentalis caurina) influences owl home ranges, and understanding this relationship will aid managers in forest management prescriptions that influence spotted owl recovery. This study describes the spatial variation in owl diet based on 4183 prey collected at 114 owl...