Predation risk shapes the use of conflicting personal risk and social safety information in guppies

When faced with uncertainty, animals can benefit from using multiple
sources of information in order to make an optimal decision. However,
information sources (e.g., social and personal cues) may conflict, while
also varying in acquisition cost and reliability. Here, we assessed
behavioral decisions of Trinidadian guppies (Poecilia reticulata), in
situ, when presented with conflicting social and personal information
about predation risk. We positioned foraging arenas within high- and
low-predation streams, where guppies were exposed to a personal cue in the
form of conspecific alarm cues (a known indicator of risk), a novel cue,
or a control. At the same time, a conspecific shoal (a social safety cue)
was either present or absent. When social safety was absent, guppies in
both populations showed typical avoidance responses towards alarm cues,
and high-predation guppies showed their typical avoidance of novel cues
(i.e., neophobia). However, the presence of social safety cues was
persuasive, overriding the neophobia of high-predation guppies and
emboldening low-predation guppies to ignore alarm cues. Our experiment is
one of the first to empirically assess the use of safety and risk cues in
prey, and suggests a threshold level of ambient risk which dictates the
use of conflicting social and personal information.