Part II: Species Accounts130
relatively low temperatures (of 25 bad-weather nest-building
events observed, 24 had occurred during rainy weather with
daily minimum temperatures below 12°C). This is consistent
with proneness to thermoregulatory stress of juvenile bushpigs
(the lower critical limit of thermoneutrality for juveniles in the
8–15 kg size range had been determined as approximately 13°C:
Seydack 1990).
Bushpig maternal behaviour was found to resemble the
general suid pattern (Frädrich 1967): suckling the young, some
limited vocal communication, naso-nasal contact and defensive
responses to neonate distress calls. Suckling bouts in bushpig
occurred during all daylight or night hours (mean suckling
duration per bout: 7.0 minutes; total suckling time per day: on
average 83 minutes; Seydack 1990). Bushpig mother sows emit-
ted short, rhythmical cohesion grunts to stimulate the neonates
to follow her. The alpha boar maintained close proximity to the
young or the sow/piglet unit. The boar–juvenile attachment was
particularly prevalent during temporary absence of the sow. The
boar was more vigilant than the sow and regularly rose to circle
around the bedded-down sow/piglet unit.
During the first phase of rearing, sow and neonates were
birth-nest- or hollow-bound (1–3 days). Thereafter, juveniles
followed their parents on relatively short excursions, with daily
ranging hardly exceeding about 200 m. One member of the
parental pair may range farther while the other stays with the
young (during a period of up to three weeks). During the third
phase (up to approximately six weeks after birth), juveniles fol-
lowed both parents, the group thus ranging as a unit, although
still restrictively influenced by the ranging capabilities of the
young (Seydack 1990). Stripe-spotted juvenile coats, lasting up
to three months of age in bushpigs (Seydack 1983), are typically
found in suid species frequenting habitat providing good cover,
such as the European wild boar and bushpig. The cryptic effects
of juvenile coats (Figures 12.2 and 12.3), prone postures and fol-
lowing-flight responses from an early age onwards is expected
to be adaptive during diurnal activity in forest habitat. The com-
bination of an early following response, group vigilance, cryptic
juvenile coats, prone response, parental guarding and defence
together form an effective suite of anti-predator tactics.
Yearling daughter sows may become involved in alloparen-
tal care to the mother–neonate unit. Alloparental care mani-
fests in tending of neonates, generally close association with the
neonates and protective concern (e.g. mock charging towards
intruders). Tending consisted of a type of grooming involving
nosing, licking or nibbling of neonates while they were suckling
as well as on other occasions. However, yearling daughter sows
with hormone levels indicative of sexual maturation do not par-
take in alloparental care and are evicted from the family group
by the alpha sow. In contrast to adult female bushpigs, which
are totally intolerant towards each other, male alpha–beta rela-
tionships are facilitated by intermale dominance hierarchies.
Assistance with paternal care, such as defence of the young
against predators, plausibly constitutes a benefit to the alpha
male (Seydack 1990).
Starvation, inclement weather and predation were respon-
sible for juvenile and yearling mortality. Pre-weaning juvenile
mortality was often associated with thermoregulatory stressfulperiods (cold and wet). Bushpig bones, mainly belonging to
juveniles two to three months old, were collected below crowned
eagle (Stephanoqetus coronatus) nests (Jarvis et al. 1980). A veri-
fied case of leopard predation on a bushpig yearling in southern
Cape forests is on record (Seydack 1990). A guarding function of
male bushpigs was evidenced; involving close spatial proximity
to the young, responsiveness to their stress-related vocalizations
and directly defensive actions towards an approaching perceived
threat. This guarding association may last into the yearling stage
(Seydack 1990). Bushpigs normally forage over larger areas than
is possible during the first one or two months postpartum when
neonate mobility is restricted. By guarding the young (babysit-
ting) the boar makes it possible for the female to roam more
widely on her own in order to meet lactational feeding demands
than would otherwise have been possible without detriment to
the survival of the offspring. Depletion of energy reserves of the
female during rearing (lactation) has implications for the fre-
quency with which she rebreeds. It is therefore adaptive for the
boar subject to a monogamous mating system to share the ener-
getic burden of reproduction, defence of the young and alleviat-
ing thermal stress experienced by the young (huddling) through
paternal care involvement.Communication
Demarcation of territorial occupancy by glandular secretions,
urine and faeces seemingly assisted in territorial defence. High
rates of scratch marking were observed along patrolling routes
(Seydack 1990). Apart from urine and faeces, various glands
are involved in the production of odorous substances (olfac-
tory communication): tusk glands, glands in the orbital region,
glands along the nape, digital glands and preputial glands. The
tusk gland (only in male bushpigs) is formed by a buccal pouch
internally lined with sebaceous follicles (Jones 1978). Externally
the pouch appears as a large swelling on the cheek, extending
from the edge of the upper lip behind the canine and opening
around the base of the upper canine. Fragments of bark and
wood accumulate in the pouch during tusk gland marking of
trees. During tusk gland marking scratch marks, together with
traces of pouch debris, remain visible on the tree. Milky exu-
dates in the forward corner of the eyes (glands in the orbital
region: Harderian glands) were observed in both sexes. A pair of
digital glands is present on the forefoot, one of them the open-
ing on the skin of the lower side of the second digit and the other
in a corresponding position of the fifth digit. The hind foot
has two similar glands in corresponding positions and a third
unpaired gland opening in the centre of the sole of the foot. Each
gland is visible externally as a small pore with a thickened cir-
cular rim. The embedded sac of the gland, about 4 mm in diam-
eter, is filled with a white waxy secretion. Marking in bushpigs
mainly involves tusk gland marking by the dominant male and
ground scratch marking by both sexes. Tusk gland marking is
performed by wiping the opening of the pouch gland on objects,
usually up and down the stems of smaller trees. Ground scratch
marking entails forcefully scratching the ground surface with
the front feet, leaving clearly visible scratches on the ground
surface (Seydack 1990). Marking is mainly performed by domi-
nant individuals of both sexes, as associated with territorial.01412:38:17