Artificial lizards were attacked more frequently in the dry than the wet season despite a greater abundance of birds in the wet season. Birds were responsible for the majority of attacks on artificial lizards and were more abundant in the wet season. We use an empirical, multi-level, tropical food web (birds–lizards–invertebrates) and a mensurative experiment (seasonal fluctuations in abundance and artificial lizards to estimate predation risk) to test these hypotheses. We tested two competing hypotheses regarding predation: (1) predation risk is dependent on predator density and (2) predation risk is dependent on the availability of alternative prey sources. Typically, factors influencing predation risk are viewed only from the perspective of predators or prey populations but few studies have examined predation risk in the context of a food web.
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