Herbivore density, impala group size, and vigilance of herbivores while feeding

There are three types of herbivorous feeders: browsers, grazers, and mixed feeders. The habitats they feed in determine whether they feed with their heads lowered or raised. The mixed feeder, Aepyceros melampus (impala) must be vigilant when feeding. My hypothesis that individuals in smaller herds would be more vigilant than larger herds was supported by my results of a significant negative correlation between group size and the number of times an individual looked up. My other findings are that there is more game in the south of Kruger National Park versus the north and that there is no significant difference in group size of herds based on location (north versus south), and vigilance of herds based on location.