Life Sciences Commons^™

Demographic Modeling Of Conservation Strategies For The Yosemite Toad (Anaxyrus Canorus), Corrina Rebecca Kamoroff

Cal Poly Humboldt theses and projects

The Yosemite toad (Anaxyrus canorus) is an anuran species endemic to the Sierra Nevada in California that, like many amphibians globally, has suffered population declines. The documented decline in A. canorus populations across their historic range highlights the need for an effective management strategy to protect the species from future extirpation. For this study, I estimated survival rates of A. canorus using a Cormack-Jolly-Seber model populated with data from a demographic study. I then used a female-only post-birth pulse stochastic Lefkovitch matrix model using vital rates I estimated and from the literature to simulate the effect of different …

Evaluating Moose Alces Alces Population Response To Infestation Level Of Winter Ticks Dermacentor Albipictus, Daniel D. Ellingwood, Peter J. Pekins, Henry Jones, Anthony R. Musante

USDA Wildlife Services: Staff Publications

Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) …

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …

Brave Spaces: Augmenting Interdisciplinary Stem Education By Using Quantitative Data Explorations To Engage Conversations On Equity And Social Justice, John R. Jungck, Jon Manon

Numeracy

In workshops and courses involving in-service teachers, participating teachers can engage in problem posing and exploration of difficult issues when they are asked to quantitatively model alternative scenarios, statistically analyze complex data, and visualize these data in multiple formats. Subsequent to these activities, discussions of sensitive issues, some even considered taboo in classrooms, can open up “brave spaces” in these teachers’ classrooms. Without coaching through elaborate facilitation strategies, the in-service teachers grappled openly with the nuances of such difficult issues and raised many alternatives involving quantitative reasoning as well as considering biological, cultural, economic, social, and political factors influencing social …

Contribution Of Juvenile Estuarine Residency In A Bar-Built Estuary To Recruitment Of Chinook Salmon (Oncorhynchus Tshawytscha), Emily Katherine Chen

Cal Poly Humboldt theses and projects

Estuaries are commonly touted as nurseries for out-migrating salmonids, providing higher prey availability than streams, a physiological transition zone, and refugee from marine predators. Yet the diversity of estuaries makes it difficult to generalize the effect they have on salmonid recruitment. In bar-built estuaries, sandbars form at the mouth of rivers during periods of low flow, closing access to the ocean and disrupting outmigration. In this thesis, I evaluated how residency in a bar-built estuary affects the growth, survival, and ultimately recruitment of Chinook salmon (Oncorhynchus tshawytscha) in Redwood Creek, California. I conducted a mark-recapture experiment on out-migrating …

Understanding The Impact Of Commercial Harvest On White Suckers (Catostomus Commersonii) In Maine, Megan A. Begley

Electronic Theses and Dissertations

The State of Maine issues an unlimited number of commercial permits for the harvest of White Suckers Catostomus commersonii in Maine’s inland waters. The fishery provides a necessary source of fresh lobster Homarus americanus bait to coastal communities at a time when other bait sources are scarce. The impacts of the increasing number of permits and subsequent numbers of fishermen on the white sucker population is unknown. The Maine Department on Inland Fisheries and Wildlife (MDIFW) has closed a number of waters due to concerns that overfishing and incidental catch of other fish species may occur.

In Chapter 1, we …

An Individual-Based Model Of Chaparral Vegetation Response To Frequent Wildfire, Timothy Lucas, Dayna Mann, Reanna Dona

Seaver College Research And Scholarly Achievement Symposium

In recent years, the Santa Monica Mountains (SMM) have been plagued by frequent wildfires which threaten the native chaparral species. Nonsprouting chaparral species are completely killed by a fire, but their seeds germinate in response to fire cues. Facultative sprouters both resprout after a wildfire and release seeds that germinate post-fire. This project is based on data collected since 1986 at a biological preserve adjacent to the Malibu campus of Pepperdine University with an average fire return interval of 7.5 years. We present a spatial model that simulates the growth, seed dispersal and resprouting behavior of individual shrubs that compete …

Modeling Interventions In The Owned Cat Population In Knox County, Tn, Evan Pierce Lancaster

Masters Theses

The rapid growth of cat populations in many communities across the United States has resulted in overpopulation and an increase in euthanasia procedures. To combat these challenges, communities have instituted spay/neuter programs as a preventative strategy. In particular, Knox County, Tennessee, has developed and implemented a program, called the Spay Shuttle, which offers free spays and neuters for owned cats throughout the county.

We develop a discrete time, age-structured model of owned female cats in Knox County to investigate the effects of implementing extra spaying intervention strategies to the population over the course of 5 years. We determine that a …

The Relationship Between Mathematical Expression And Biological Insight: Some Issues In Community Ecology Modeling, Exemplified By The Logistic Equation, Peter J. Taylor

Working Papers on Science in a Changing World

The relationship between mathematical expression and biological insight is a central problem for modelers in community ecology. In this paper I distinguish three interpretations of this relationship: models as redescriptions as observations; models as capturing fundamental or generative biological relations; and models as an aid in exploring how to formulate the inquiries we put to nature. I aim to show that we can reduce ambiguities and confusion and ecological theory if we hold the different interpretations clearly in mind. I conclude by advancing an overall strategy of model building—de/composition—in which each of the interpretations plays a role. The logistic equation, …