Females facilitate male patch discovery in a wild fish population

When individuals are more socially responsive to one sex than the other, the benefits they get from foraging socially are likely to depend on the sex composition of the social environment. We tested this hypothesis by performing experimental manipulations of guppy, Poecilia reticulata, sex compositions in the wild. Males found fewer novel food patches in the absence of females than in mixed-sex compositions, while female patch discovery did not differ between compositions. We argue that these results were driven by sex-dependent mechanisms of social association: Markov chain-based fission-fusion modeling revealed that males reduced sociality when females were absent, while less social individuals found fewer patches. Females were similarly social with or without males. Finally, males, but not females, preferred to join females over males at patches. Our findings reveal the relevance of considering how individual and population-level traits interact in shaping the adaptive value of social living in the wild.