Fear effects associated with predator presence and habitat structure interact to alter herbivory on coral reefs

Authors

Andrew G. Bauman, National University of SingaporeFollow
Jovena C. L. Seah, National University of Singapore
Fraser A. Januchowski-Hartley, Swansea University
Andrew S. Hoey, James Cook University - Townsville, Australia
Jenny Fong, National University of Singapore
Peter A. Todd, National University of Singapore

ORCID

0000-0001-9260-2153

Document Type

Article

Publication Title

Biology Letters

ISSN

1744-957X

Publication Date

10-2-2019

Keywords

Risk effects, Coral reefs, Predator-prey interactions, Herbivory, Sargassum

Abstract

Non-consumptive fear effects are an important determinant of foraging decisions by consumers across a range of ecosystems. However, how fear effects associated with the presence of predators interact with those associated with habitat structure remain unclear. Here, we used predator fish models (Plectropomus leopardus) and experimental patches of the macroalga Sargassum ilicifolium of varying densities to investigate how predator- and habitat-associated fear effects influence herbivory on coral reefs. We found the removal of macroalgal biomass (i.e. herbivory) was shaped by the interaction between predator- and habitat-associated fear effects. Rates of macroalgal removal declined with increasing macroalgal density, likely due to increased visual occlusion by denser macroalgae patches and reduced ability of herbivorous fishes to detect the predators. The presence of the predator model reduced herbivory within low macroalgal density plots, but not within medium- and high-density macroalgal plots. Our results suggest that fear effects due to predator presence were greatest at low macroalgal density, yet these effects were lost at higher densities possibly due to greater predation risk associated with habitat structure and/or the inability of herbivorous fishes to detect the predator model.

DOI

10.1098/rsbl.2019.0409

Volume

15

First Page

20190409

Comments

Data accessibility

Data are available from Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.m88gq46 [30].

Electronic supplementary material is available online at https://doi.org/10.6084/m9.figshare.c.4671383.

Additional Comments

This research was supported by the Singapore National Research Foundation, Prime Minister's Office, Singapore under the Marine Science Research and Development Programme and the AXA Postdoctoral Fellowship (A.G.B.).

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

NSUWorks Citation

Andrew G. Bauman, Jovena C. L. Seah, Fraser A. Januchowski-Hartley, Andrew S. Hoey, Jenny Fong, and Peter A. Todd. 2019. Fear effects associated with predator presence and habitat structure interact to alter herbivory on coral reefs .Biology Letters : 20190409 . https://nsuworks.nova.edu/occ_facarticles/1286.