Temporally separated species are often thought to have limited competition over a shared resource. However, early arriving species may consume a limited resource such that later arriving species have access to fewer resources and thus experience competitive effects, even if they are temporally separated (i.e., they experience legacy effects from the early species). The presence of a predator might affect potential legacy effects by influencing the behavior or survivorship of the early species. Using a mesocosm experiment, I examined whether the presence of non-native Western Mosquitofish (Gambusia affinis) mediated legacy effects in the interaction of two temporally separated species of tadpoles, early arriving American Toads (Anaxyrus americanus) and late arriving Bullfrogs (Rana catesbeiana). Anaxyrus americanus tadpoles reduced R. catesbeiana tadpole growth despite all A. americanus tadpoles metamorphosing 8 d before the introduction of R. catesbeiana tadpoles into the mesocosms (i.e., legacy effects).  Gambusia affinis had limited effects on A. americanus (1 d delay in metamorphosis but no effect on survivorship or size at metamorphosis) and positive effects on R. catesbeiana (increased growth). There were no significant interactions between the A. americanus tadpole density and G. affinis treatments. In conclusion, I found evidence of significant legacy effects of A. americanus tadpoles on R. catesbeiana tadpoles, but no evidence that G. affinis mediated the legacy effects.

Data were collected from a mesocosm experiment. Some of the data are means of all individuals in a mesocosm. No other processing has occurred.

The data are in a comma separated values format and so should be openable by any software that can use such files.