Suidae - bushpigs and warthogs
What do bushpigs and warthogs eat?
Both display omnivorous tendencies (cating animal and plant ma terial) wieL food being located mostly by smell.
Both are essentially omnivores the bushpig probably more so. Bushpigs have varied diet. They are happy to subsist on fruits, pods and other items from nes, and will root (furrow) for rhizomes, bulbs and tubers. They will gladly enio worms or insect larvae they find during rooting. Rooting is the behaviour of using the hard cartilaginous disc on the end of the nose to dig for food. The lower canines are also sometimes used. Bushpigs do not drop to their knees during rooting ac warthogs do. Warthogs prinmarily feed on grass, and root for rhizomes, bulhs a and tubers, the latter being more a winter food-source. Ihey will no doubt also cat the odd invertebrate, although the bushpig, living in and feeding more among leaf litter is more likely to encounter them. There have been one or two records of warthog eating carrion probably when nutritionally stressed. I have witnessed a young male gnawing on an abandoned zebra kill over a period of two days. It is not clear what if anything, was being digested although it aPpeared that membranes, sinew and cartilage/ skin were the focus of attention. It also nuzzled the bloodstained ground and fed on the drying stomach contents. Bushpigs have, however, been reported on numerous occasions to have killed and eaten various animals, mostly domestic, and any to have eaten carrion. What is their social structure? This differs slightly for the two species, and they are therefore discussed separately Warthog, They live in matriarchal groups, called sounders, consisting of a female with young. More than one adult female with all their young sometimes live together. Young males tend to form bachelor groups, but as they get older they become solitary and only temporarily join female Groups (called sostnders) of warthogs of this size are not too conimc where large predators abound (and because the piglets tend to have a bigh general mortality). These social groups are not usually stable where more than one adult female with her offspring is present, and the adult males do not usually spend much time in these sounders. Small bachelor groups 1will, however, occur from time to time. sounders when females are in oestrus. They all share a common (natal) home range that is not defended. Favourite feeding, wallowing and denning areas may, however, be the scene of aggression when groups or individuals come together Males will tusk and mark trees with tusk gland secretions. The higher the marking is, the bigger and, theretore, more dominant the male is a good way ot advertising his presence in an area. Home ranges will overlap.
The Bushpig
They are also non-territorial with overlapping home ranges, but the social structure is markedly ditterent. Harems, led by one male, are the norm. A male literally owns the temales and vigorously protects the sounder, especially when there are young against foreign males. As with warthogs, there may be aggressive encounters at favourite sites Within the range where males engage in 'showing oft displays to
deter one another from attacking. The males also mark trees with their tusks and tusk glands
Do wartnogs dig their own burrows?
Usually not, though they are capable of doing so. This is probably dependent on the number of holes and animal species, resident within the range, that dig extensively. Indeed, why dig when you can just move in? Although warthogs in some areas will excavate their own burrow systems, this is not usually the case in areas where large numbers of holes exist that were excavated primarily by aardvark. Warthogs move in and renovate, adding chambers and possibly enlarging and diversifying the system. The nose is a powerful digging tool and an etfective scoop for gerting rid of sand. The curved upper tusks are also used ro dig. They tend to prefer burrow systems with a singie entrance, making it easier to protect from within. It is well known that they enter their burrows backwards. This is probably done to make sure they don't get stuck head-first, and it protects the head from what might already be lurking within. It also puts the tusks in a position to be used quickly if the entrance is breached. The central part of the chamber appears to be excavated lower than the rest, creating a surrounding ledge where the piglets lie.
This ensures their safety should water enter during storms, although this Is still a Significant mortality factor. Small burrows are only used temporarily. Sounders may make use of a number of different burrows within the home range. These burrows are occupied on a first-come first-served basis.
BUSHPIGS AND WARTHOGS
What enemies and defence mechanisms do they have? Owing to their SIZe they are vulnerable to a variety of enemies. They are also more susceptıble than most other species to sudden climatic changes or conditions. Active defence is limited to use of the tusks and butting with the head, particularly by males. Passive defence centres on visual displays and characteristics such as the white hairs on the sides of young warthogs faces that may mimic tusks. They also flee at high speed. Warthogs sometimes escape by retreating into burrows when pursued; bushpigs do not. The young fall prey to a number of enemies- from eagles, pythons and crocodiles to any number of cat or dog carnivores. Adults, at 50 100 kg, are more formidable, but all the larger predators will hunt them. Warthogs are especially tavoured by leopard in areas where they are abundant, but cheetahs seldom risk attacking adult warthogs. I have seen male leopards on numerous occasions actively walk from one termite mound to another in search of occupied burrows, and upon finding one, settle in for a long wait.
Bushpigs are generally considered more aggressive than warthogs, but their dense habitat makes them particularly vulnerable to leopard. Theý can also fall prey to lions on their nocturnal feeding forays. As far as defence is concerned, their acute senses of smell and hearing help locate danger but their eyesight is relatively poor.
Warthogs are the only pigs in Africa to hibit this phenomenon,
and the reason for it may lie in the fact that they are the only ones that live and mostly graze in open savannah. The other species,
ike bushpig, live in the forest and generally have enough food in the
form of fallen fruits, and other goods in the Winter. Rooting at
this time takes up less of their day, and the litter and soil are generally
softer than on the sunbakedd open areas where warthogs live.
In Winter warthogs rely almost entirely on rooting to find adequate
and sufficient food, and spend most of their time doing this. This
puts a strain on the animal, which is alleviated by dropping to the 'knees and resting while rooting, and possibly creates greater leverage with which to dig in hard soils. Thus the 'knees' have developed heavy callouses. Warthogs, having to work relatively harder to obtainb food than their forest relatives, spend a lot of time on their 'knees' for comfort and convenience, it not out of necessity. One could then ask why they do not have much shorter front legs to facilitate this strategy, but such a feature would make them
vulnerable to attack and less agile in escape.
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