@article{70401c6990bf4ef9963c7001de81f3fd,
title = "Green turtles shape the seascape through grazing patch formation around habitat features: Experimental evidence",
abstract = "Understanding how megaherbivores incorporate habitat features into their foraging behavior is key toward understanding how herbivores shape the surrounding landscape. While the role of habitat structure has been studied within the context of predator–prey dynamics and grazing behavior in terrestrial systems, there is a limited understanding of how structure influences megaherbivore grazing in marine ecosystems. To investigate the response of megaherbivores (green turtles) to habitat features, we experimentally introduced structure at two spatial scales in a shallow seagrass meadow in The Bahamas. Turtle density increased 50-fold (to 311 turtles ha−1) in response to the structures, and turtles were mainly grazing and resting (low vigilance behavior). This resulted in a grazing patch exceeding the size of the experimental setup (242 m2), with reduced seagrass shoot density and aboveground biomass. After structure removal, turtle density decreased and vigilance increased (more browsing and shorter surfacing times), while seagrass within the patch partly recovered. Even at a small scale (9 m2), artificial structures altered turtle grazing behavior, resulting in grazing patches in 60% of the plots. Our results demonstrate that marine megaherbivores select habitat features as foraging sites, likely to be a predator refuge, resulting in heterogeneity in seagrass bed structure at the landscape scale.",
keywords = "Chelonia mydas, habitat structure, herbivory, landscape of fear, plant–herbivore interactions, seagrass, Thalassia testudinum",
author = "Smulders, {F. O.H.} and Bakker, {E. S.} and O'Shea, {O. R.} and Campbell, {J. E.} and Rhoades, {O. K.} and Christianen, {M. J.A.}",
note = "Funding Information: This study was carried out as part of the project “Global defaunation and plant invasion: cascading effects on seagrass ecosystem services” appointed to M. J. A. Christianen (NWO 016.Veni. 181.002). Additional funding was provided by a US National Science Foundation grant to J. E. Campbell (OCE‐1737247). F. O. H. Smulders was supported by the 2019 Ecology Fund of the Royal Netherlands Academy of Arts and Sciences. We thank Enrique Bethel, Delphine Carrol, Duncan O'Brien, Adam Southern, Cameron Raguse, Isabella Primrose Hartman, Tom Glucksman, Larry Eger, William Bigelow, and Michael Thorndyke for field assistance. All work was conducted under Department of Marine Resources Research permits MAMR/FIS/17/ and MAMR/FIS/9/17B. This is contribution #1501 from the Coastlines and Oceans Division of the Institute of Environment at Florida International University. Publisher Copyright: {\textcopyright} 2022 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.",
year = "2022",
doi = "10.1002/ecy.3902",
language = "English",
journal = "Ecology",
issn = "0012-9658",
publisher = "John Wiley and Sons Ltd",
}