The influence of abiotic and biotic factors on patterns of consumption across a range of consumer body sizes
October 2021 - September 2022
- Ferguson College of Agriculture/
A fundamental goal of ecology is determining the role of consumers in ecosystems, and identifying drivers of consumer resource use is a crucial component of achieving this goal. Both inter- and intraspecific variation in body size are known to drive aspects of consumer resource use, and understanding patterns of resource use with increasing body size is important for understanding macroecological patterns of ecosystem structure. In addition to body size, patterns of consumption may be influenced by environmental heterogeneity. Abiotic factors may influence resource use directly through their effects on metabolism, performance, and visibility, or indirectly through their influence on prey availability, predator density, and prey refugia. Streams are an ideal system to test the effects of environmental heterogeneity on consumer resource use because abiotic and biotic characteristics vary along longitudinal gradients (the river continuum) and streams host diverse consumer communities that feed on a wide variety of resources. We compared the diet variability of Green Sunfish (Lepomis cyanellus) across a gradient of body sizes and stream sizes. This research contributes a first step in developing a unified perspective of foraging patterns by combining prevailing theories in foraging ecology and incorporating the influence of abiotic and biotic factors.