Diversity, prevalence, and intensity of gastrointestinal helminth infections in migratory, resident, and sedentary plains zebras (Equus quagga) in Masai Mara National Reserve and Lake Nakuru National Park, Kenya.

Abstract

The diversity, prevalence and intensity of parasitic infections are influenced by factors such as movement patterns and land area available to the host. Zebras are known to harbour various genera of gastrointestinal helminths and facilitate parasite movement across large geographic areas through migration. Despite the harmful effects of helminths and their consequences on host population dynamics, little is known regarding helminth infection patterns in migratory, resident, and sedentary zebras. This study compared the diversity, prevalence, and intensity of helminth infections in zebras with different host movement patterns and space availability. Faecal samples were collected from migratory, resident, and sedentary groups of zebras between 2014 and 2015 and screened for helminth infection. They were infected by diverse groups of helminths including nematodes, trematodes and cestodes with the most prevalent being strongyle type nematodes. No significant difference in the diversity and prevalence was observed between the "three groups". Larvae were also recovered and identified species, cyathostomes, Strongylus edentatus, S.vulgaris, S. equinus, and Trichostronglus in order of abundance. The intensity of infection with the strongyle type nematodes, was highest in the migratory, then sedentary and lowest in resident zebras. It is plausible that the migratory zebras have higher energy demands and poor nutrition, resulting in reduced immune function hence high nematode burdens. Similarly, the sedentary population had high nematode burdens possibly due to high pasture contamination and depressed immunity due to the artificially restricted movement. The latter observation is particularly important in the design and size of sanctuaries in relation to parasitism.