Sex-dependent audience effect in foraging guppies

The presence of bystanders can influence the behaviour of a forager, which has mainly been studied in primates and birds. We tested the effect of the absence and presence of an unfamiliar audience (females, males, and their combination) near or far from a food patch, on the foraging behaviour of guppies (Poecilia reticulata). Our investigation includes both males and females, recognising that different social dynamics and reproductive strategies between the sexes could lead to varied responses to audience effects. For each focal fish, we measured the latency to start feeding, bite frequency, time spent near the audience, and overall mobility. Both males and females started feeding faster when food was close to any audience type. Specifically, females exhibited a faster feeding response in the presence of a female audience. Males reduced their feeding rate in the presence of male and mixed audiences, while both sexes increased their consumption when food was close to the audience. Focal fish, irrespective of their sex, spent more time in the vicinity of the audience zone when the audience was present but, surprisingly, females spent less time with a female audience compared to others. Only females increased their mobility when the food patch was far from any audience. Here we show that guppies adjust their foraging behaviour in the presence of an audience. The specific responses observed varied between the sexes, reflecting the distinct social trade-offs faced by each sex.