Prey incorporate information reliability when assessing risk of predation. Here, we report results of an experiment testing avoidance of chemical alarm cues derived from skin extract of blacknose shiners, Notropis heterolepis (BNS), attraction of a visible shoal of five BNS, and the combination of both, on fishes in Deming Lake where BNS occur. We then repeated the experiment in nearby Budd Lake where BNS do not occur. BNS avoided traps with conspecific alarm cues but did not respond to the presence of BNS shoals. Fathead minnows, Pimephales promelas (FHM) avoided traps chemically labeled with BNS alarm cue when a shoal was absent and avoided BNS shoals when traps were labeled with water (control). When both BNS alarm cue and BNS shoal were combined, antipredator response to BNS alarm cue invoked a shoaling response with the BNS shoal in the trap. Redbelly dace, Chrysomus eos (RBD) responded weakly to BNS cues in Deming Lake and ignored them in Budd Lake. Non-cyprinid species (brook stickleback Culaea inconstans and pumpkinseed sunfish, Lepomis gibbosus) did not respond to either olfactory or visual cues of BNS in Deming Lake. In Budd Lake, neither avoidance of BNS alarm cue nor attraction to BNS shoals surpassed the threshold of statistical significance, indicating a role of familiarity and learned recognition of risk and safety in cross-species reactions to olfactory and visual cues of heterospecifics.

Data were collected from field populations of small fishes in two lakes in Itasca State Park. Data are in an Excel file.