Foraging rates from metabarcoding: Predators have reduced functional responses in wild, diverse prey communities

Authors

Stella F. Uiterwaal, University of Nebraska-Lincoln, Washington University in St. Louis, National Great Rivers Research and Education Center, Saint Louis UniversityFollow
John DeLong, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2-8-2024

Citation

Ecology Letters. 2024;27:e14394. https://doi.org/10.1111/ele.14394

Comments

Open access.

Abstract

Functional responses describe foraging rates across prey densities and underlie many fundamental ecological processes. Most functional response knowledge comes from simplified lab experiments, but we do not know whether these experiments accurately represent foraging in nature. In addition, the difficulty of conducting multispecies functional response experiments means that it is unclear whether interaction strengths are weakened in the presence of multiple prey types. We developed a novel method to estimate wild predators' foraging rates from metabarcoding data and use this method to present functional responses for wild wolf spiders foraging on 27 prey families. These field functional responses were considerably reduced compared to lab functional responses. We further find that foraging is sometimes increased in the presence of other prey types, contrary to expectations. Our novel method for estimating field foraging rates will allow researchers to determine functional responses for wild predators and address long-standing questions about foraging in nature.