Influence of intra‐ and interspecific variation in predator–prey body size ratios on trophic interaction strengths

Ecology and Evolution

Olaf L. F. Weyl¹  Michael W. McCoy²  Tatenda Dalu³  Horst Kaiser⁴  Ryan J. Wasserman⁵  Ross N. Cuthbert⁶  Arnaud Sentis⁷  Mhairi E. Alexander⁸  Jaimie T. A. Dick⁹ 

[1] DSI/NRF Research Chair in Inland Fisheries and Freshwater Ecology South African Institute for Aquatic Biodiversity Makhanda South Africa;Department of Biology East Carolina University Greenville SC USA;Department of Ecology and Resource Management University of Venda Thohoyandou South Africa;Department of Ichthyology and Fisheries Science Rhodes University Makhanda South Africa;Department of Zoology and Entomology Rhodes University Makhanda South Africa;GEOMAR Helmholtz‐Zentrum für Ozeanforschung Kiel Kiel Germany;INRAE Aix Marseille UniversityUMR RECOVERAix‐en‐Provence France;Institute for Biomedical and Environmental Health Research School of Health and Life Sciences University of the West of Scotland Paisley UK;Institute for Global Food Security School of Biological Sciences Queen's University Belfast Belfast UK;

关键词: Bluegill;    context‐dependency;    functional response;    interaction strength;    largemouth bass;    piscivory;   

DOI  :  10.1002/ece3.6332

来源: DOAJ

【 摘 要 】

Abstract Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of interaction strengths. However, studies quantifying the combined influence of intra‐ and interspecific variation in predator–prey body size ratios are lacking. We use a comparative functional response approach to examine interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra‐ and interspecific predator–prey body mass ratios on the scaling of attack rates and handling times. Type II functional responses were displayed by both predators across all predator and prey size classes. Largemouth bass consumed more than bluegill at small and intermediate predator size classes, while large predators of both species were more similar. Small prey were most vulnerable overall; however, differential attack rates among prey were emergent across predator sizes. For both bluegill and largemouth bass, small predators exhibited higher attack rates toward small and intermediate prey sizes, while larger predators exhibited greater attack rates toward large prey. Conversely, handling times increased with prey size, with small bluegill exhibiting particularly low feeding rates toward medium–large prey types. Attack rates for both predators peaked unimodally at intermediate predator–prey body mass ratios, while handling times generally shortened across increasing body mass ratios. We thus demonstrate effects of body size ratios on predator–prey interaction strengths between key fish species, with attack rates and handling times dependent on the relative sizes of predator–prey participants. Considerations for intra‐ and interspecific body size ratio effects are critical for predicting the strengths of interactions within ecosystems and may drive differential ecological impacts among invasive species as size ratios shift.

【 授权许可】

Unknown