Black wildebeest
Black wildebeest act as hosts to a number of external and internal parasites. A study of the animal in Karroid Mountainveld (Eastern Cape Province, South Africa) revealed the presence of all the larval stages of the nasal bot flies "Oestrus variolosus" and "Gedoelstia hässleri". The first instar larvae of "G. hässleri" were found in large numbers on the dura mater of wildebeest calves, specially between June and August, and these later migrated to the nasal passages. Repeated outbreaks of mange (scab) have led to large-scale extinctions. The first study of the protozoa in blue and black wildebeest showed the presence of 23 protozoan species in the rumen, with "Diplodinium bubalidis" and "Ostracodinium damaliscus" common in all the animals.
Wildebeest
Not all wildebeest are migratory. Black wildebeest herds are often nomadic or may have a regular home range of . Bulls may occupy territories, usually about apart, but this spacing varies according to the quality of the habitat. In favourable conditions, they may be as close as , or they may be as far apart as in poor habitat. Female herds have home ranges of about in size. Herds of nonterritorial bachelor males roam at will and do not seem to have any restrictions on where they wander.