a group of four tick species in Africa; the taxonomy and ecology of this complex is of great significance because its members are vectors of relapsing fever spirochetes; members of the complex include Ornithodoros moubata (various hosts), Ornithodoros compactus (tortoises), Ornithodoros apertus (porcupines), and Ornithodoros porcinus (warthogs); a domestic subspecies of Ornithodoros porcinus, in turn, forms three strains that feed chiefly on humans, fowl, and swine.