The most well-known bone eaters are hyenas. With their powerful jaws, hyenas are able to crush through bone, which is then digested in their incredibly strong stomach acids. The crushing power of their jaws comes from huge jaw muscles which attach to a ridge that runs along the top of the hyenas’ skull.
Many other creatures on the reserve use the bones that the hyenas do not eat. Osteophagia has been recorded in several different species of herbivores ranging from giraffe to zebra, impala to tortoise. It is believed that these animals chew and suck on bone fragments in order to absorb calcium and phosphorous from the bone. This is seen more often in areas with phosphorous-poor soils. We recently saw a herd of kudu chewing on the bones of an old buffalo kill and you could see how methodically they moved these through their mouths, chewing and using their saliva to dissolve the necessary nutrients.
There are two other forms of ‘phagia’ that we can observe out here that are practiced by almost all the herbivores. The first would be geophagia, which is when animals eat soil. Most of the time this soil will be eaten from areas called sodic (containing sodium) sites. These sodic sites have accumulated salts over many thousands of years. The herbivores come here to obtain these salts as they are not prevalent in the plants they eat.
The other type of ‘phagia’ is called copraphagia, where animals eat dung. All herbivores require bacteria in their digestive systems in order to digest plant material. It is therefore necessary for herbivore babies to eat their mothers’ dung in order to kick-start their digestive systems before they begin to eat plants. Tortoises have also been known to eat the scat of hyenas. This is in order for them to gain access to the very high calcium content in the dung. This high calcium content is responsible for hyena scat being white.