Graduation Date
Fall 2022
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Wildlife
Committee Chair Name
Dr. Daniel Barton
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
Dr. Barbara Clucas
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
Dr. Erik Jules
Third Committee Member Affiliation
HSU Faculty or Staff
Fourth Committee Member Name
Robert Grasso
Fourth Committee Member Affiliation
Community Member or Outside Professional
Keywords
Yosemite toad, Demographic, Modeling, Conservation, Strategies
Subject Categories
Wildlife
Abstract
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 management scenarios and to optimize a supplementation or reintroduction management plan. Without any management action, small populations of A. canorus populations have ≥50% risk of quasi-extinction over the next 13 years. The implementation of effective management strategies is critical to prevent further extinction of existing small populations. My results suggest that the effectiveness of a supplementation or a reintroduction management plan is dependent on the initial population size of the receiving population, life stage at release and number of individuals released into a wild population. I found that supplementing small toad populations with female adults is the most effective supplementation strategy to increase the stochastic growth rate and minimize the risk of quasi-extinction. This thesis suggests that modeling A. canorus population dynamics and trends of extant populations can help inform conservation strategies.
Citation Style
APA
Recommended Citation
Kamoroff, Corrina Rebecca, "Demographic modeling of conservation strategies for the Yosemite toad (Anaxyrus canorus)" (2022). Cal Poly Humboldt theses and projects. 612.
https://digitalcommons.humboldt.edu/etd/612