During a morning monitoring session last week on Zimanga Private Game Reserve in South Africa, our conservation volunteers came across a very relaxed herd of giraffe grazing on one of their favourite foods – the knob thorn tree. Interestingly, one giraffe stood apart from the group chewing on something that was far different from the succulent leaves that the others were grazing on. This giraffe was chewing on an old bone!
Giraffe are the tallest herbivores in the world and feed of a variety of plant species. They are not carnivorous! However, when nutrients are lacking in their normal daily diets, and they become nutritionally stressed, they will eat bone to get phosphorous and calcium their bodies require. Bones are manipulated in and out the mouth by the tongue while being sucked and chewed.
This behaviour is called osteophagy. Osteophagia means “feeding on bone”. The bones are not swallowed but simply dropped when the individual has gained enough nutrients or tires of the activity. This behaviour has been seen in a number of herbivore species particularly in larger herbivores the giraffe and kudu.
Have any of you seen a giraffe doing this?
Volunteers: Ulrich Connan, Mélanie Cagné, Claudine Cagne, Nadine Stähli and Max Stähli.
Thanks to Ulrich and Nadine for the photos.
With Coenraad Wildlife ACT