Foraging height levels and the risk of gastro-intestinal tract parasitic infections of wild ungulates in an African savannah eco-system

Abstract

Grazing herbivores mainly feed at low feeding height levels, while browsers select food items above ground level. Previous studies on gastrointestinal tract (GIT) nematode parasite burdens of African ungulates have suggested that browsing species hereby minimise the risk of infection with parasites. Here, we investigated the influence of feeding height levels on the pasture larval contamination level (PCL) in a natural African savannah eco-system in Queen Elizabeth National Park, western Uganda. The prevalence and mean abundance of infectious GIT nematode larvae on the pasture were used as measures of pasture contamination. Vegetation samples were examined following standard larval isolation, concentration and counting techniques. We found the feeding height level to be significantly related to the occurrence of infectious GIT nematode larvae, and the contamination was highest at low feeding levels. There was no statistically significant seasonal variation in the prevalence or mean abundance of the contamination of pastures with nematode larvae.