Part II: Species Accounts94
with forefeet and snout – not the tusks. Burrows are most often
modified aardvark Orycteropus afer and porcupine Hystrix spp.
holes, but sometimes underground erosion gullies or caves
in rock (Figure 9.5). Cave burrows are most permanent and
intensively used, but least common. They are followed by ero-
sion gullies and then aardvark holes in terms of permanency
and intensity of use. Burrows are not defended except from
within (Bigourdan 1948; Sowls & Phelps 1966; Bradley 1972;
Cumming 1975; Mason 1982; Somers et al. 1994, 1995; Somers
1997; White & Cameron 2009).
Most burrows have a single entrance, are < 1 m underground,
and end in a simple chamber. Entrance holes are typically
30–50 cm in height and 30–60 cm wide. Some are more com-
plex, with three entrances, a maze of tunnels, and three or more
chambers. This particularly applies to erosion gully burrows.
When it is cold, dry grass is sometimes scraped with the front
feet or carried by mouth into the burrow. Reproductive females
are more selective in choice of burrows than are other warthog
(White & Cameron 2009). Adult males spend less time in bur-
rows than do adult females and non-adults. Indeed, they do not
always sleep in burrows at night, instead resting in long grass, a
slight hollow, or a thicket (Geigy 1955; Cumming 1975; Somers
et al. 1994).
Cumming (1975) made the following observations concern-
ing use of burrows by P. a f r i c a n u s in north-west Zimbabwe:
• A sounder uses up to at least 10 burrows. Up to five burrows
are used in central east South Africa (Somers et al. 1994).
• Many more burrows are available than are used on any one
night (52 burrows/km^2 ). There are at least 42 burrows/km^2
in central east South Africa (Somers et al. 1994).• Few burrows are in continuous use; most are used <50 per
cent of nights, and none are used >70 per cent of nights.
Individual burrows are used 15–100 per cent of the time in
central east South Africa (White & Cameron 2009).
• Burrow location, permanence, structure, and type are
important in determining intensity of use.
• Burrows are occupied on a ‘first come, first served’ basis.
Upon arrival at the burrow, the entrance is sniffed and, if
occupied, the warthog moves on.
• More than one sounder (up to at least seven sounders) may
use a burrow, but there is seldom more than one sounder in
a burrow on the same night. In Kenya, however, up to three
sounders (18 individuals) may use the same burrow on the
same night (Radke 1991).
• The need to sleep in burrows places a limit on the size of
sounders as space in a burrow is restrictive. Therefore, large
sounders are rare. See also Somers et al. (1995).
• Burrows are also used by many other species, particularly
porcupines and spotted hyaenas Crocuta crocuta. See also
White and Cameron (2009).Predator avoidance may be the factor determining burrow
selection by P. a f r i c a n u s (Cumming 1975; White & Cameron
2009). Lion Panthera leo and leopard Panthera pardus wait at
burrows to catch arriving and departing animals. Hence, P. a f r i-
canus typically approach a burrow against the wind, thereby
catching the scent of an awaiting predator. Adults and subadults
may or may not reverse into burrows. Presumably they reverse
into burrows to face predators. When departing a burrow, the
lead animal may pause well within entrance, sniff, listen for aFigure 9.5 Sounder of common
warthogs Phacochoerus africanus
leaving a cave burrow at Lolldaiga Hills
Ranch, central Kenya. Camera trap
image by Tom Butynski and Yvonne
de Jong..01112:33:32