Data from: Marine subsidies change short-term foraging activity and habitat utilization of terrestrial lizards

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.