Life Sciences Commons^™

Winter Diet Of Bobolink, A Long-Distance Migratory Grassland Bird, Inferred From Feather Isotopes, Rosalind B. Renfrew, Jason M. Hill, Daniel H. Kim, Christopher Romanek, Noah G. Perlut

Biology Faculty Publications and Presentations

Effective conservation of migratory bird populations depends on advancements in our understanding of processes throughout the life cycle. Fundamental information about wintering ecology (e.g., habitat use and diet composition) remains limited, which limits assessment of threats to populations during winter. Bobolink (Dolichonyx oryzivorus) is a year-round grassland obligate and Nearctic-Neotropical migrant that undergoes 2 complete molts each year, including a complete prealternate molt on the South American wintering grounds. This unusual winter molt provides a rare opportunity to examine, using stable isotope analysis, the timing and contribution of foraging resources in the Bobolink diet prior to northbound migration from disparate …

Intestinal Microbiota Diversity Of Pre-Smolt Steelhead (Oncorhynchus Mykiss) Across Six Oregon And Washington Hatcheries, Christina Carrell Yildirimer

Dissertations and Theses

The Pacific Northwest is known for its once-abundant wild salmonid populations that have been in decline for more than 50 years due to habitat destruction and commercial overexploitation. To compensate, federal and state agencies annually release hundreds of thousands of hatchery-reared fish into the wild. However, accumulating data indicate that hatchery fish have lower fitness in natural environments, and that hatchery rearing negatively influences return rates of anadromous salmonids. Recently, mounting evidence revealed that the richness and diversity of intestinal microbial species influence host health. We examined the gut microbiota of pre-migratory hatchery-reared steelhead (Oncorhynchus mykiss) to assess …

Predicting Parturition In A Long-Gestating Species: Behavioral And Hormonal Indicators In The Asian Elephant (Elephas Maximus), Heather Kelly Velonis

Dissertations and Theses

Captive populations of Asian elephants (Elephas maximus) in North America are not self-sustaining, and increasing reproductive success within captive populations is a high priority. The ability to accurately predict parturition can have a direct impact on elephant welfare. Elephants in captivity often require significant preparation and management throughout the birthing process, and complications during labor and delivery can necessitate immediate intervention, including stillbirth, protracted labor, maternal aggression towards a newborn calf, and dystocia. Being able to predict when parturition will commence can ensure appropriate staff is available and adequate monitoring is performed. Routine endocrine sampling can be used …

Columbia River Basin Salmon And Steelhead Long-Term Recovery Situation Assessment, Oregon Solutions, William D. Ruckelshaus Center

National Policy Consensus Center Publications and Reports

In the fall of 2012, after consulting with a wide range of salmon recovery partners, NOAA Fisheries asked Oregon Consensus and the William D. Ruckelshaus Center (university-based, neutral, third-party institutions devoted to promoting collaborative governance and consensusbased public policy) to conduct an independent, impartial situation assessment to explore regional views about how best to approach comprehensive, long-term salmon and steelhead recovery in the Basin. The centers assembled an Assessment Team comprised of practitioners and academics from Washington, Oregon and Idaho.

The Assessment Team conducted 206 semi-structured interviews with individuals selected for their knowledge of, engagement in, and/or concern for salmon …

Why Do Animals Do What They Do, When They Do It? Characterizing The Role Of The Hypothalamus-Pituitary-Adrenal Axis In Seasonal Life-History Transitions, Catherine Anne Dayger Forbes

Dissertations and Theses

Resource availability follows seasonal cycles in environmental conditions. To align physiology and behavior with prevailing environmental conditions, seasonal animals integrate cues from the environment with their internal state. One of the systems animals use to integrate those cues is the hypothalamus-pituitary-adrenal (HPA) axis and its primary effector, glucocorticoid hormones. The HPA axis has wide-ranging effects on physiology and behavior and, in the context of a glucocorticoid stress response, is known to mediate tradeoffs between immediate survival and future fitness. The HPA axis also plays an important role in facilitating predictable life-history events. Variation in HPA axis activity has been reported …

Transcriptomic Analysis Of Maternally Provisioned Cues For Phenotypic Plasticity In The Annual Killifish, Austrofundulus Limnaeus, Amie L. Romney, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Background: Genotype and environment can interact during development to produce novel adaptive traits that support life in extreme conditions. The development of the annual killifsh Austrofundulus limnaeus is unique among vertebrates because the embryos have distinct cell movements that separate epiboly from axis formation during early development, can enter into a state of metabolic dormancy known as diapause and can survive extreme environmental conditions. The ability to enter into diapause can be maternally programmed, with young females producing embryos that do not enter into diapause. Alternately, embryos can be programmed to “escape” from diapause and develop directly by both maternal …

Quantifying The Impacts Of A Novel Predator: The Distinctive Case Of The Oregon Spotted Frog (Rana Pretiosa) And The Invasive American Bullfrog (Rana (Aquarana) Catesbeiana), Kyle Scott Tidwell

Dissertations and Theses

The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat degradation and loss. The introduced American Bullfrog (Rana (Aquarana) catesbeiana) has been widely implicated in those declines, but the basis of that contention has been difficult to characterize. The bullfrog occurring at every site of recent Oregon Spotted Frog extirpation has focused concern about its impact.

Here, I present a suite of interconnected studies that examine the behavioral ecology of both species to better understand the potential …

Factors Affecting Snowy Plover Chick Survival In A Managed Population, Stephen J. Dinsmore, Eleanor P. Gaines, Scott F. Pearson, David J. Lauten, Kathleen J. Castelein

Institute for Natural Resources Publications

Understanding survival of precocial chicks in the period immediately following hatching has important conservation implications because population growth is often sensitive to post-hatching survival. We studied federally threatened Western Snowy Plover (Charadrius nivosus nivosus) broods at the northern limit of their range in coastal Oregon (n ¼ 1,157) and Washington (n ¼ 84) from 1991 to 2011 in an attempt to understand seasonal, annual, and spatial patterns of chick survival. In Oregon, plover chick survival increased with age, varied between sites, and was greater at sites with predator management. The mean probability of surviving from hatch to fledging at 28 …