A worldwide decline in amphibian populations has intensified the need for data comparing the influence of habitats on population dynamics and the potential for local extinction. From a conservation perspective it is important to understand the connections between ecology, geography, and genetics across landscapes that are increasingly affected by human influences and other uncontrollable environmental events such as climate change. The purpose of this study is to examine the landscape-level genetic patterns of Western toads, Bufo (Anaxyrus) boreas, and to conclude if gene flow is occurring between ponds. This will allow conservation practitioners to understand geographic features that might impede connectivity among ponds, and increase the risk of extinction. For this study, 143 individuals from 12 ponds in the Central Valley of California were genotyped using 10 microsatellite loci. Population genetic software (e.g., GENEPOP, STRUCTURE) was utilized to describe the genetic diversity of populations and to evaluate hypotheses relating to population structure. Results indicate ample genetic variation across the study landscape, high levels of gene flow between ponds, and a lack of a strong distance effect on genetic structure. The data suggest that over short timescales (one breeding season) western toads are resilient to low levels of disturbance to habitat adjacent to breeding ponds. These data are important, considering the potential for increasing anthropogenic stress faced by these populations.
Advisor(s) or Committee Chair
Dr. Jarrett Johnson, Dr. Ajay Srivastava
Murrell, Morgan, "Population Genetics of the Western Toad (Bufo boreas) in the Central Valley of California" (2013). Honors College Capstone Experience/Thesis Projects. Paper 440.