Predicting Predator Nutrient Intake From Prey Body Contents

Abstract

Predator-prey interactions can have important consequences for the flow of nutrients through food webs and ecosystems. Given the diversity of predator-prey interactions, it is infeasible to directly measure predator nutrient intake when feeding on each potential prey. Elements are an important measure of nutrient flow through food webs but do not fully account for variation in the quality of nutrients in which they are present. The overall goal of this study was to test if measures of macronutrients, metabolizable protein and lipid, could be used to improve measures of elemental ingestion by predators when feeding on prey. This experiment used two prey that differed widely in exoskeleton content (i.e., larval vs. adult mealworms) because arthropod prey vary widely in this trait and it has the potential to complicate nutritional measurements since it contains nitrogen but is indigestible to most predators. Our results show that the elemental content of whole prey was a poor predictor of elemental consumption by predators. Macronutrient content of whole prey was a strong predictor of macronutrient ingestion by predators, which suggested that it may be a useful measure of predator consumption. Using macronutrient data to create a hybrid element-macronutrient measure of whole prey resulted in better predictions of total elemental ingestion by predators. These results suggest that combining elemental and macronutrient approaches in the study of trophic transfers of nutrients, especially during predator-prey interactions, has the potential to increase our ability to understand and predict the flow of nutrients through food webs and ecosystems.

Latitude‐associated evolution and drivers of thermal response curves in body stoichiometry

“…Yet, the few studies explicitly investigated this relationship and also found no or weak links (Wilder & Jeyasingh, ; Zhang, Jansen, Smolders, De Meester, & Stoks, ). To advance insights into the (de)coupling between elemental and macromolecular body contents, it may be important to study in more detail the macromolecular content of the exoskeleton (Wilder, Barnes, & Hawlena, ) as this makes up an important part of the total body mass in insects (Lease & Wolf, ). Furthermore, better characterizing the macromolecules may be important.…”

Differences in macronutrient content of common aquatic macroinvertebrates available as prey for young-of-the-yearScaphirhynchussturgeons in the lower Missouri River

“…Energetic and elemental analysis alone can be a poor predictor of energy available in prey (Wilder et al 2019). Elemental analyses of prey items can identify coarse measures of quality but are unable to distinguish between compounds that have similar elemental content but different digestibility (Anderson and Pond 2000;Anderson et al 2004;Wilder and Eubanks 2010).…”

Sexual Dimorphism in the Multielemental Stoichiometric Phenotypes and Stoichiometric Niches of Spiders

“…Only a few studies to date have considered the ecological stoichiometry and elemental nutrition of spiders (e.g., [32,35,[40][41][42]); therefore, a large gap in data exists, and it is hard to perform comparisons leading to strong and meaningful conclusions. Hence, we will supplement our reasoning with available data collected for other arthropods.…”

“…Processes involved in ecophysiology and life history evolution are likely to differentially affect females and males, imposing sex-specific nutritional limitations and even imposing a conflict between the sexes in reaching sex-specific nutritional optima [13,23]. At the same time, stoichiometric phenotypes are species-specific and reflect the nutritional demands of individuals [15,24,32]. Therefore, we hypothesized (1) that taxon-specific and sex-specific differences in the multielemental stoichiometry of the studied spiders and in their stoichiometric niches would be observed.…”