RESEARCH ARTICLE Effect of an Invasive Plant and Moonlight on Rodent Foraging Behavior in a Coastal Dune Ecosystem Matthew D. Johnson*, Yesenia L. De León Department of Wildlife, Humboldt State University, Arcata, California, 95521, United States of America *
[email protected] Abstract Understanding how invasive plants may alter predator avoidance behaviors is important for granivorous rodents because their foraging can trigger ripple effects in trophic webs. Previous research has shown that European beach grass Ammophila arenaria, an invasive OPEN ACCESS species in coastal California, affects the predation of other seeds by the rodents Microtus californicus, Peromyscus maniculatus, and Reithrodontomys megalotis. This may be due Citation: Johnson MD, De León YL (2015) Effect of an Invasive Plant and Moonlight on Rodent Foraging to lower perceived predation risk by rodents foraging in close proximity to the cover provided Behavior in a Coastal Dune Ecosystem. PLoS ONE by Ammophila, but this mechanism has not yet been tested. We examined the perceived 10(2): e0117903. doi:10.1371/journal.pone.0117903 predation risk of rodents by measuring the ‘giving up density’ of food left behind in experi- Academic Editor: Anna R. Armitage, Texas A&M mental patches of food in areas with and without abundant cover from Ammophila and University at Galveston, UNITED STATES under varying amount of moonlight. We found strong evidence that giving up density was Received: March 19, 2014 lower in the thick uniform vegetation on Ammophila-dominated habitat than it was in the Accepted: December 2, 2014 more sparsely and diversely vegetated restored habitat. There was also evidence that moonlight affected giving up density and that it mediated the effects of habitat, although with Published: February 13, 2015 our design we were unable to distinguish the effects of lunar illumination and moon phase.