Data from: Marine subsidies change short-term foraging activity and habitat utilization of terrestrial lizards
Kenny, Heather V., University of Hawaii at Manoa
Wright, Amber N., University of California, Davis
Piovia-Scott, Jonah, Washington State University
Yang, Louie, University of California, Davis
Spiller, David A., University of California, Davis
Schoener, Thomas W., University of California, Davis
Yang, Louie H., University of California, Davis
Published Oct 25, 2018 on Dryad.
Cite this dataset
Kenny, Heather V. et al. (2018). Data from: Marine subsidies change short-term foraging activity and habitat utilization of terrestrial lizards [Dataset]. Dryad. https://doi.org/10.5061/dryad.bc0qk
Resource pulses are brief periods of unusually high resource abundance. While population and community responses to resource pulses have been relatively well-studied, how individual consumers respond to resource pulses has received less attention. Local consumers are the first to respond to a resource pulse, and the form and timing of individual responses may influence how the effects of the pulse are transmitted throughout the community. Previous studies in Bahamian food webs have shown that detritivores associated with pulses of seaweed wrack provide an alternative prey source for lizards. When seaweed is abundant, lizards (Anolis sagrei) shift to consuming more marine-derived prey and increase in density, which has important consequences for other components of the food web. We hypothesized that the diet shift requires individuals to alter their habitat use and foraging activity, and that such responses may happen very rapidly. In this study, we investigated the immediate responses of lizards to an experimental seaweed pulse. We added seaweed to 5 treatment plots for comparison with 5 control plots. Immediately after seaweed addition, lizards decreased average perch height and increased movement rate, but these effects persisted for only two days. To explore the short-term nature of the response, we used our field data to parametrize heuristic Markov chain models of perch height as a function of foraging state. These models suggest a “Synchronized-satiation Hypothesis,” whereby lizards respond synchronously and feed quickly to satiation in the presence of subsidy (causing an initial decrease in average perch height) and then return to the relative safety of higher perches. We suggest that the immediate responses of individual consumers to resource-pulse events can provide insight into the mechanisms by which these consumers ultimately influence community-level processes.
Lizard habitat use and foraging activity scored from video observations.
Each row of the data set represents a single video observation bout of a lizard (n = 87). The data set captures lizard habitat use and foraging activity in treatment and control plots before and after the addition of a seaweed subsidy.