Ripe fleshy fruits contain an enormous diversity of metabolites that influence ecological interactions with mutualistic and antagonistic species. This dissertation investigates the impact of fruit secondary metabolites on the foraging behavior and digestive physiology of bats (Chapters 2-4) while applying insights from basic chemical ecology to inform forest regeneration strategies (Chapter 5). The studies were conducted in northeastern Costa Rica at La Selva Biological Station. Chapter Two examines the variability and associations between nutrients and secondary metabolites within ripe Piper sancti-felicis fruits, showing that intraindividual variation of chemical traits can surpass interindividual variation and associations between chemical traits are scale-dependent, varying in strength and direction. Chapter Three explores how bats balance nutrient acquisition with defensive metabolite avoidance and the impact of metabolite consumption on bat nutrient absorption. It reveals that nutrient composition is the primary driver of bat foraging behavior and that defensive metabolites can interfere with protein absorption. Chapter Four further uses untargeted metabolomics to explore the influence of secondary metabolites on nutrient absorption, demonstrating that four commercial secondary metabolites induce dose-dependent changes in bat fecal metabolome, altering essential nutrient absorption. Chapter Five translates principles of chemical ecology into practical use by demonstrating the effectiveness of synthetic volatiles in attracting fruit bats and increasing seed rain. Taken together, this dissertation shows the impact of defensive metabolites on a key seed disperser while demonstrating the potential application of chemical ecology to address forest regeneration challenges. / Doctor of Philosophy / Fleshy fruits exhibit a remarkable chemical complexity. Fruit pulp is not only rich in essential nutrients (sugars, proteins, and lipids) but also contains a diverse array of other chemicals collectively known as secondary metabolites. These metabolites shape ecological interactions between fruits and frugivores. This dissertation focuses on understanding the ecological and physiological effects of fruit chemistry on frugivores. The studies were conducted at La Selva Biological Station in northeastern Costa Rica, focusing on fruit bats and pepper plants. Chapter two examines the relationships and variation between nutrients and toxins within ripe fruits of pepper plants (Piper sancti-felicis), finding that the chemical variation within a single plant can exceed the differences between separate plants. Also, depending on the scale studied, toxins and nutrients can be positively or negatively associated. Chapters Three and Four describe the preferences of a fruit bat (Carollia perspicillata) for nutrients and toxins, showing that nutrients are the primary driving force behind food choices and demonstrating that certain fruit toxins alter the ability of bats to absorb nutrients, including different sugars, proteins, and lipids. Chapter Five demonstrates the potential of synthetic chemical lures to attract fruit bats and enhance seed dispersal, offering a promising strategy to promote forest regeneration in degraded areas. Overall, this research demonstrates how fruit chemicals can significantly impact fruit bats, which play a crucial role in dispersing seeds and maintaining forest diversity.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/118651 |
| Date | 22 April 2024 |
| Creators | Gelambi Desiato, Mariana |
| Contributors | Biological Sciences, Whitehead, Susan, Moore, Ignacio T., Langwig, Kate Elizabeth, Tholl, Dorothea Berta Christine |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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