Bd in the Bay Area: Characterizing Batrachochytrium dendrobatidis Prevalence in Anurans by Physiology, Climate, and Local Environment
Abstract/Contents
- Abstract
- Batrachochytrium dendrobatidis (Bd) is a parasitic waterborne fungus that has recently decimated frog populations worldwide. This Bd-induced loss of frogs has caused harm to both human and natural systems, and is considered a top priority within conservation science. However, the dynamics of Bd are still not fully understood, especially in different geographies and climates. The proportion of frogs infected with Bd –known as the infection prevalence– can vary by physiology, season, and habitat, even within a given region. One ecologically important location where frog Bd prevalence is still unknown is the San Francisco Bay Area. In this honors thesis, I begin to characterize Bd infection prevalence in the Bay Area’s frogs by exploring how the proportion of frogs infected differs by species, sex, age, body condition, month, and habitat type. The diversity of environments across Stanford University-owned lands serve as the focal region of this study. From 2013 to 2019, frogs across this region were captured and non-invasively tested to diagnose infection. My results suggest that the overall Bd infection prevalence is 21.7% within these Bay Area frogs. Among the five species studied, vulnerable Rana draytonii had the lowest infection prevalence (9.62%). Surprisingly, the invasive species Lithobates catesbeianus, known elsewhere to readily contract Bd, also had a low infection prevalence relative to other species studied. Bd-positive frogs exhibited lower mass to body length ratio, a proxy for general health, than their Bd-negative counterparts. When grouped by life stage, tadpoles were least often infected by Bd, with a prevalence of just 1.49%. When comparing habitat type, the lowest infection prevalence was in undeveloped pools (3.64%), followed by semi-urban creeks. Dammed reservoirs demonstrated the highest infection prevalence (69.23%) followed by highly developed ponds and ditches, but were not statistically significant. These findings lay the groundwork for further study and have the potential to inform targeted conservation efforts for the Bay Area’s at-risk species.
Description
| Type of resource | text |
|---|---|
| Date created | May 18, 2020 |
Creators/Contributors
| Author | Drake, Osanna Vivian |
|---|
Subjects
| Subject | Batrachochytrium dendrobatidis |
|---|---|
| Subject | chytridiomycosis |
| Subject | anurans |
| Subject | Bay Area |
| Subject | California |
| Subject | frogs |
| Subject | habitat |
| Subject | environment |
| Subject | Rana draytonii |
| Subject | Earth Systems |
| Genre | Thesis |
Bibliographic information
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- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).
Preferred citation
- Preferred Citation
- Drake, Osanna Vivian. (2020). Bd in the Bay Area: Characterizing Batrachochytrium dendrobatidis Prevalence in Anurans by Physiology, Climate, and Local Environment. Stanford Digital Repository. Available at: https://purl.stanford.edu/tj820rj0492
Collection
Undergraduate Honors Theses, Doerr School of Sustainability
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- Contact
- osanna@stanford.edu
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