Life Sciences Commons^™

Genetic Structure And Connectivity Of The Endangered Giant Kangaroo Rat (Dipodomys Ingens) In A Heterogeneous Environment, Nathan Alexander

Cal Poly Humboldt theses and projects

Movement ecology and dispersal are important aspects of species’ life histories that can inform conservation and management. Dispersal is often cryptic and difficult to detect, but recent advances genetic technology and applications have provided new approaches to identifying and describing dispersal patterns. Giant kangaroo rats (Dipodomys ingens) are an endangered heteromyid that appear to persist in small subpopulations in a heterogeneous environment of their northern range, the Ciervo-Panoche Natural Area, California. Previous work suggested high levels of genetic diversity between populations with genetic distances not being correlated to geographic distances. Here, I identified landscape population structure through clustering …

Evaluation Of Parameter Estimation And Field Application Of Transgenerational Genetic Mark-Recapture, Ryan W. Whitmore

Cal Poly Humboldt theses and projects

Use of a genetic-based analogue of the traditional mark-recapture method (transgenerational genetic mark-recapture, tGMR) is rapidly expanding as a means to estimate total escapement of Pacific salmon. The tGMR approach is similar to the simple Lincoln-Peterson mark-recapture method. In tGMR, adults returning to fresh water to spawn are collected in the first sampling occasion and their juvenile offspring that are migrating out to sea are collected during the second sampling occasion. Recaptures are determined by the number of parent-offspring pairs identified through genetic parentage analysis of the adult and juvenile collections. Two versions of tGMR are currently in use, referred …

Molt In Individuals: A Description Of Prealternate Molt Phenology In A Population Of Snowy Plovers In Humboldt County, California, Alexa Dejoannis

Cal Poly Humboldt theses and projects

Molt in birds is an essential physiological process. Intrinsic and extrinsic conditions, such as age, sex, location, or food stress, may cause individual variation in molt phenology. This study describes the timing of prealternate molt in western snowy plovers (Charadrius nivosus nivosus) wintering in Humboldt County, California, USA. Between July 2014 and April 2015, I photographed uniquely marked plovers twice a month and assigned dates of initiation and completion. I modeled sex, age, hatch date, and breeding location as predictors of molt phenology. I observed prealternate molt from October to April, which is earlier than previously described. Males …

Performance And Morphology In Sequoiadendron Genotypes Outside Of Their Range, Christopher M. Valness

Cal Poly Humboldt theses and projects

In its current fragmented distribution in 75 groves along the western slope of the Sierra Nevada, Sequoiadendron giganteum (SEGI) may be vulnerable to extreme shifts in environmental conditions such as warming temperatures and drought stress, which may reduce the already limited habitat for SEGI in native groves. Interest in outplanting of this iconic species for the objectives of genetic conservation and timber utilization due to decay resistance of heartwood would be supported by information on population variation to inform seed collection for these plantings. To that end, I assessed three SEGI common-garden trials which had been planted in spring 1981 …

Ninety-Two Years Of Tree Growth And Death In A Second-Growth Coast Redwood Forest, Benjamin Iberle

Cal Poly Humboldt theses and projects

Mature second-growth coast redwood (Sequoia sempervirens) forests are an important and uncommon resource in the redwood region. Development of second-growth redwood forests beyond rotation age (~50 years) is not well understood. Continuous long-term data are especially lacking, considering that the maximum possible age of second-growth stands is now over 150 years. Two permanent observation plots in Arcata, CA, established in 1923 by Woodbridge Metcalf and last measured in 1990, provide a unique opportunity to examine the development of coast redwood forest regenerating after logging in ~1880. We surveyed the Metcalf plots using modern methods and assembled a complete …

Baseline Monitoring And Characterization Of Rocky Intertidal Fish Communities In Northern California, Kevin D. Hinterman

Cal Poly Humboldt theses and projects

A network of new Marine Protected Areas (MPAs) has been established in northern California, covering 137 square miles of coastline, with the goal of maintaining commercially and recreationally important species and to preserve biodiversity. This is the first study in California to create a biodiversity and phylogenetic baseline of rocky intertidal fish communities within MPAs and nearby reference sites. Diversity, abundance, and size structure of intertidal fishes were compared among seven sites from Fort Bragg to Crescent City, CA during the summers and winters of 2014 and 2015. A total of 34 species were collected throughout sampling, just three less …

Seasonal Habitat Selection Of The North American Porcupine (Erethizon Dorsatum) In A Coastal Dune Forest, Cara L. Appel

Cal Poly Humboldt theses and projects

Wildlife-habitat relationship studies are important for understanding the factors that determine where species occur in space and time. Habitat selection by generalist species should be studied on fine spatial and temporal scales to avoid masking important differences between seasons, localities, or orders of selection. I conducted the first study of habitat use and general ecology of North American porcupines (Erethizon dorsatum) in a coastal dune environment. Specifically, I assessed changes in body mass, home range size, and habitat selection in relation to the potential for seasonal nutritional and survival bottlenecks as reported elsewhere. Although they are considered generalists, …

Evaluating Brandt’S Cormorant (Phalacrocorax Penicillatus) Reproductive Success: Effects Of Parental Care Behaviors And Estimating Individual Chick Survival, Shannon Murphy

Cal Poly Humboldt theses and projects

Variation in reproductive success is widely measured in seabird biology in an effort to indicate changes in the marine environment, or understand basic questions about ecology or conservation of seabirds. When variation in seabird reproductive success is suggested to indicate changes in the marine environment without identifying the proximate causes of such variation, inference is limited to association, and the proximate causes themselves could prove more effective as indicators. My study informs this problem by examining and quantifying proximate causes of variation in reproductive success, at the level of nests and individual chicks.

I used video of Brandt’s Cormorant ( …

Early Seral Mixed-Conifer Forest Structure And Composition Following A Wildfire Reburn In The Sierra Nevada, Erin Alvey

Cal Poly Humboldt theses and projects

Before the era of modern fire suppression, California’s northern Sierra Nevada mixed-conifer and yellow pine forests were self-regulating; recurring short-interval, low-mixed severity wildfires maintained forest structure and composition, which in turn exerted bottom-up controls on subsequent wildfires. As a result of fire suppression, and coupled with the effects of climate warming and other anthropogenic disturbances, the fundamental structure of mixed-conifer and yellow pine forests has shifted. Wildfires may now be increasing in size, severity, and frequency across western North America. However, little is known about the post-fire impacts of repeat wildfire on a forest after a long era of suppression. …

An Experimental Test Of Response By Common Ravens To Nest Exclosures, Teresa R. King

Cal Poly Humboldt theses and projects

Common ravens (Corvus corax) are intelligent generalists and a principal predator affecting population recovery of several threatened and endangered species, including the threatened western snowy plover (Charadrius nivosus nivosus). In Humboldt County, raven predation is a primary cause of low nest survival. Nest exclosures, cages around eggs that preclude entry by predators but allow plovers access to incubate, are known to increase nest success. However, speculation exists that exclosures may attract predators. The aims of this study were to summarize corvid distribution on Clam Beach County Park and Little River State Beach, evaluate habitat features associated …

Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman

Cal Poly Humboldt theses and projects

The Scott and Shasta rivers, Klamath River tributaries, experience spatial disparity in habitat quality in spring and summer as a result of historical and current land-use. Juvenile Coho Salmon (Oncorhynchus kisutch) born in the upper tributary reaches often rear in natal streams before migrating to sea. However, those born in the lower reaches often encounter unsuitable habitat and emigrate during their first spring to seek non-natal rearing habitats. It is assumed that these early outmigrants are population losses. This study evaluated first-summer survival, and contribution to the adult population, of non-natal rearing juveniles in the Klamath River Basin. …

Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest

Cal Poly Humboldt theses and projects

Soil carbon (C) affects the active gases in the atmosphere, nutrient cycling, and diversity of flora and fauna. Soil organic matter (SOM) is partially comprised of C, and a widely-accepted ratio of 0.58 organic carbon (OC) to organic matter (OM) is used to measure soil C on a landscape scale. However, this ratio varies according to vegetation, depth, hydrology, and may lead to miscalculations of soil C and SOM estimates. Soil C and SOM are inherently complex and it is not completely understood which environmental factors have the most influence in their formation, which occurs on a time scale of …

The Effectiveness Of Physical Activity Interventions On Young Individuals With Autism Spectrum Disorder: A Meta-Analysis, Adam Nacario

Cal Poly Humboldt theses and projects

Objective: The purpose of the study is to examine the efficacy of physical activity interventions and practices on psychomotor, cognitive, or affective outcomes on young individuals diagnosed with Autism Spectrum Disorder (ASD).

Methods: Standard meta-analytical procedures determining inclusion criteria, literature searches in electronic databases, coding procedures, and statistical methods were used to identify and synthesize articles retained for analysis. Cohen’s d (1988) will be utilized in order to interpret effect sizes and quantify research findings. The impact was assessed using coding procedures that categorize independent variables.

Results: A total of 23 independent samples (N=896) were utilized in this analysis. Results …