Diel activity and diet of three sympatric sticklebacks in tidal salt marsh pools

Abstract
The activity patterns and diet of the adults of three sympatric sticklebacks, Gasterosteus aculeatus, Gasterosteus wheatlandi, and Pungitius pungitius, are compared to learn how three sympatric species share time and food resources. Catch data from unbaited traps indicate that all species are equally diurnal. Females of all species feed almost exclusively in the early morning. No periodicity was observed in the feeding of males compared with females, because males fed infrequently. The diets of the three species were similar though the importance of certain prey items varied with species and sex. Results show that resource partitioning along the dimensions of food type and time are of minor importance in explaining coexistence of the three species during their breeding season.