Oxpeckers – Cleaners or Parasites?
The two species of oxpecker which make up the family Buphagidae are endemic to sub-Saharan Africa. The yellow-billed oxpecker (Buphagus africanus) is slightly larger and more widely found than its red-billed cousin (Buphagus erythrorhynchus) which is generally only found in the eastern part of sub-Saharan Africa.
Oxpeckers are medium-sized birds which some ornithologists regard as a subfamily of starlings (Sturnidae). Their plumage is light brown with the most prominent distinguishing factor between the two species being the color of their bills. They lay two or three eggs in their nests in holes or the hollows of trees and use hair plucked from their hosts to line their nests. Open country is the habitat of choice for these gregarious, insect eating birds.
The oxpecker’s name, both English and scientific, is derived from their feeding habits. Oxpeckers perch on large mammals, wild and domestic, and eat parasites such as ticks and botfly larvae which lodge in mammalian skin. Many consider this to be a symbiotic relationship where both parties benefit. The bird gets food and the animal gets rid of its parasites. However, the favorite food of an oxpecker is blood and, although they eat blood filled ticks, they also peck at their hosts wounds thereby feeding directly on the animal’s blood and encouraging more parasites to settle on the animal. The relationship between the bird and its host is therefore to some extent parasitic in nature.
Red-billed oxpeckers use a scissoring motion to search through the hair of their hosts and they are often seen working through the manes of a giraffe in this manner. Yellow-billed oxpeckers, on the other hand, use a pecking motion, possibly because their bills are thicker and less dexterous. They favor short-haired animals such as buffalo and rhino. Oxpeckers are often observed working deep inside the ears of animals in search of food, a habit which most animals seem to tolerate.
In the early 1900s, oxpeckers were considered to be extinct as a breeding species in South Africa. The over-hunting of buffalo and rhino, as well as arsenic dipping of domestic cattle was possibly to blame for this situation. The re-introduction of oxpeckers into the Kruger National Park has resulted in breeding colonies spreading. As a result, the oxpecker has been moved from being listed as extinct, to vulnerable.
Certainly the oxpecker seems to be somewhat of a mixed blessing to its host, with the benefits of having parasites removed by the bird, generally outweighing the bird’s own parasitic behavior.