We studied wintering Semipalmated Plovers (Charadrius semipalmatus) in a mangrove and open bay site in coastal Venezuela to determine whether the minor sexual dimorphism in bill and tarsus lengths in this species was correlated with sexual differences in habitat use, behavior during foraging, and diet. We found no significant differences between the sexes in either habitat use on the mudflats or distances to conspecifics. Neither sex exhibited territorial behavior. Males used significantly more shallow pecks than did females, who used more repetitive probing, particularly at the open bay site. Diets differed between the sexes in the relative abundance of prey in the fecal samples in both habitats, with samples from males containing significantly more dipteran larvae and samples from females containing more copepods and bivalves. Prey size did not vary between the sexes. We documented significant site differences in habitat use, foraging behavior, and diet, probably as a result of differences in prey availability.