Oecologia

, Volume 184, Issue 1, pp 139–149

Predation risk influences feeding rates but competition structures space use for a common Pacific parrotfish

  • Kathryn Davis
  • P. M. Carlson
  • D. Bradley
  • R. R. Warner
  • J. E. Caselle
Behavioral ecology – original research

Abstract

In terrestrial systems it is well known that the spatial patterns of grazing by herbivores can influence the structure of primary producer communities. On coral reefs, the consequences of varied space use by herbivores on benthic community structure are not well understood, nor are the relative influences of bottom-up (resource abundance and quality), horizontal (competition), and top-down (predation risk) factors in affecting spatial foraging behaviors of mobile herbivorous fishes. In the current study we quantified space use and feeding rates of the parrotfish, Chlorurus spilurus, across a strong gradient of food resources and predator and competitor abundance across two islands with drastically different fisheries management schemes. We found evidence that while feeding rates of this species are affected by direct interference competition and chronic predation risk, space use appears to be primarily related to exploitative competition with the surrounding herbivore community. We found no evidence that predation risk influences diurnal foraging space use in this small bodied parrotfish species. Additionally, we found the influence of chronic predation risk on feeding rates of this species to be less dramatic than the results of recent studies that used model predators to measure acute behavioral responses of other species of herbivorous fishes. Our results indicate that the non-consumptive effects of predators on the foraging behaviors of coral reef herbivores may be less dramatic than previously thought.

Keywords

Herbivory Coral reef Territory size Foraging behavior Chronic risk 

Supplementary material

442_2017_3857_MOESM1_ESM.docx (7.7 mb)
Supplementary material 1 (DOCX 7895 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  1. 1.Department of Ecology, Evolution, and Marine BiologyUniversity of California Santa BarbaraSanta BarbaraUSA
  2. 2.Donald Bren School of Environmental Science and ManagementUniversity of California Santa BarbaraSanta BarbaraUSA
  3. 3.Marine Science InstituteUniversity of California Santa BarbaraSanta BarbaraUSA

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