Pick your poison : assessing dietary preference & alkaloids in South American poison frogs
Abstract/Contents
- Abstract
- Poison frogs (Family Dendrobatidae) are native to Central and South America, and many carry small molecule alkaloids in their skin for defense against predation. These chemical defenses are acquired through their diets, but dietary prey availability and consumption have never been directly compared. In order to fill this gap, my dissertation work takes an integrative approach to understand which arthropods dendrobatids consume and what motivates them to do so. We found that leaf litter of forest and pasture habitats differed significantly in ant community structure and that forest and pasture frogs (Oophaga sylvatica) differed significantly in diet and alkaloid profiles.. Finally, ant species composition of frog diets resembled the surrounding leaf litter, but diets were less variable, which suggests that frogs tend to consume particular ant species within each habitat. Our next study's results validated our previous study's findings, as frog alkaloid content and ant consumption and availability all differed between the five localities. Further, we compared the diets of a sympatric and non defended, cryptic Dendrobatid species, Hyloxalus infraguttatus, to those of Oophaga sylvatica and found that defended O. sylvatica eats more ants and mites. Overall, our findings suggest that poison frogs have dietary preferences for certain ants. Finally, supplemented our field-based chapters with lab-based Chapter 4, where we conducted dietary preference assays in a controlled laboratory setting, along with nutritional evaluations of ecologically relevant prey items (ants, beetles, flies, larvae). We used Dyeing Poison frog (Dendrobates tinctorius) to test how prior alkaloid consumption and prey traits (size, taxon) would influence dietary preferences, and found that frogs preferred interacting with small prey items. Taxonomic prey preferences were further tested as we experimentally increased their chemical defense load by feeding frogs decahydroquinoline (DHQ), an alkaloid compound similar to those naturally found in their diet. Contrary to our expectations, overall preferences did not change during alkaloid consumption. Finally, we assessed the protein and lipid content of the prey items used in our assays, and found that small ants have the highest lipid content while large larvae have the highest protein content. Our mutually informative studies provide insights into the evolutionary history of diet-acquired defenses by combining manipulative, individual-level behavioral data with ecologically relevant field studies. More generally, these studies have broader implications for our general understanding of community ecology and the evolution of adaptive traits.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Moskowitz, Nora |
|---|---|
| Degree supervisor | O'Connell, Lauren A |
| Thesis advisor | O'Connell, Lauren A |
| Thesis advisor | Dirzo, Rodolfo |
| Thesis advisor | Gordon, Deborah (Deborah M.) |
| Thesis advisor | Peay, Kabir |
| Degree committee member | Dirzo, Rodolfo |
| Degree committee member | Gordon, Deborah (Deborah M.) |
| Degree committee member | Peay, Kabir |
| Associated with | Stanford University, Department of Biology |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Nora A. Moskowitz. |
|---|---|
| Note | Submitted to the Department of Biology. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/pd079td9505 |
Access conditions
- Copyright
- © 2022 by Nora Moskowitz
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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