Last year, we noted that one of our calves in Salta, Argentina, was grazing on its knees. So I -being a veterinarian- was asked what was wrong with it. I had no clue so I diagnosed it as suffering from the “Warthog Syndrome” as it reminded me of the African pigs. It was only a few days later that my wife realized the origin of the “condition”. The calf got used to kneel down to be able to graze further while tied to a stake! It soon recovered but by then the warthogs’ feeding technique had already sparked my curiosity.
After some thought I decided that warthogs suffer from a rare Nature’s design fault: their neck is too short to reach the ground hence the need to genuflect to feed! As this was a rather strong conclusion, I decided to follow up and “Google” it.
I read that warthogs graze but also dig bulbs and tubers during the dry season. They do this on its calloused and padded knees using its snout and tusks. They have extremely short necks and their limbs are somewhat long so, assuming this position helps them root and graze more efficiently. However, warthogs are often more susceptible to predator attacks when they adopt these vulnerable feeding stances!
Still unconvinced I dug deeper and consulted the well known and knowledgeable zoologist Jonathan Kingdom. He explains that warthogs have rather long legs that enables them to run faster than other pig species and this increased the distance of the mouth to the ground hence the need for kneeling to feed as it has not evolved an elongated snout! I quote: “Kneeling is an in-born behaviour pattern as even new-born piglets kneel to feed. However, it is not only the behaviour that is in-born, because the callosities characteristic of the carpal joints of the warthog’s forelegs are present on embryos”.
I was now confused as I could not understand the difference between having a short neck or longer than needed legs! Further, it appears that warthogs evolved longer legs to run fast but compromised their safety by feeding on their knees running the risk of not seeing their predators!
Desperate to find an explanation, I looked into the African wisdom and found a traditional Zulu story on the subject. It says that at some stage the warthog was inside its burrow when a lion approached it and, when the latter roared, the trembling warthog knelt down to beg the lion not to eat it! The lion had already fed and forgave the warthog. However, it told the pig to stay on its knees forever. That is the reason that it eats with its bottom up and its nose in the dust!
So, having checked general information, science and folklore I am still convinced that the warthog is the casualty of a design fault by Mother Nature!
 Kingdom, J. (1982). East African Mammals: An Atlas of Evolution in Africa, Vol. 3, Part B. The University of Chicago Press.