Influence of cannibalism on Arizona tiger salamander (Ambystoma mavortium nebulosum) stress physiology

Project Abstract

Cannibalism (intraspecific predation) is common in many species because it provides nutritional advantages and reduces within-population competition. Cannibalism is favored in populations with fast growth rates, which leads to opportunistic larger individuals preying on smaller animals of their own species. In the presence of cannibals, small amphibian larvae that are not eaten experience reduced growth rates and activity levels. Such sublethal effects can impact population dynamics and have subsequent cascading effects on surrounding communities. Cannibalism may cause variation in stress responses of individuals; smaller animals may have elevated or chronic stress, as they have a higher risk of becoming consumed by their own species. Chronic stress has adverse effects on long-term individual health that can result in increased mortality. Corticosterone is the primary hormone produced by amphibians in response to stress, and stress can be quantified through measurement of this hormone. Thus, the objective of my study is to assess how the interaction of body size, body condition, and cannibalism causes corticosterone variation in the well-studied population of Arizona tiger salamanders (Ambystoma mavortium nebulosum) at the Mexican Cut Nature Preserve, Colorado. Within 3 minutes of capturing the animal, I will use a non-invasive skin swabbing method to collect corticosterone samples from at least 20 larvae of variable sizes from each pond. Samples will be stored in ethanol at 4°C until they can be processed within the laboratory at Murray State University. Samples will be processed using Arbor Assays corticosterone ELISA kits. A general linear mixed effects model will be used to determine variation in corticosterone samples relative to predation (no cannibalism vs. cannibalism) and predator density. My study will provide a better understanding of the ecological importance of cannibalism among top predators in aquatic ecosystems, as well as the influence of cannibalism and subsequent risk of predation on stress levels in larval salamanders.

Funding Type

Research Grant

Academic College

Jesse D. Jones College of Science, Engineering and Technology


Wildlife and Conservation Biology


Bachelor of Science




Howard H. Whiteman, PhD

Academic College

Jesse D. Jones College of Science, Engineering and Technology

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