Part II: Species Accounts126
took place primarily during 10:00 and 18:00 h (warmer time
periods of summer days) and between 2:00 and 6:00 h in win-
ter (coolest time periods of winter nights). Generally noctur-
nal and biphasic (reflected in three-hourly movement patterns:
Table 12.1), bushpig avoid temperature extremes through resting
(Table 12.2).
These findings are consistent with thermal neutral zones
of between 13 and 30°C determined for juveniles (10 kg) and
8–25°C for adults (Seydack 1990).Feeding Ecology
Omnivorous Diet
Bushpigs are omnivorous generalists obtaining the largest pro-
portion of their diet by superficial rooting of the ground layer.
Their bunodont dentition and monogastric digestive system
is in alignment with their omnivorous diet. Forage fractions
include fruit, above-ground herbage (mainly monocotyle-
dons, fern fronds), subterranean items (rhizomes, tubers, roots,
corms,) and items of animal origin (vertebrates and inverte-
brates). Bushpig foraging of agricultural crops may be trouble-
some to farmers (Skinner et al. 1976; Melton et al. 1989). Other
records of bushpig diets include those of Thomas and Kolbe
(1942), Breytenbach and Skinner (1982), and Melton et al.
(1989). Jones (1984) recorded 29 food items foraged by bush-
pig in the Matobo National Park (Zimbabwe), selected oppor-
tunistically according to seasonal availability. Forage fractions
studied in South African bushpig populations differed region-
ally (moist southern Cape forests and arid Valley Bushveld of the
eastern Cape) and seasonally (Table 12.3).
Fruit represent important forage items in summer and
autumn in southern Cape forests (Table 12.3), originating
from Podocarpus falcatus, Rhoicissus tomentosa and in fruit
mast years from Olea capensis ssp. macrocarpa and PodocarpusTable 12.2 Bushpig activity patterns subject to interaction between
temperature and season.Interaction: activity and temperature for summer and winter
(Seydack 1990)
Relative incidence of four-hour resting periods (frequencies)
Summer Winter
Day (6–18 h) 24 9
Night (18–6 h) 4 15
Temperature effects
Summer day temperatures (°C) N Mean s
Active 7 20.4 3.7
Resting 8 25.8 4.9
Winter night temperatures (°C)
Active 15 12.0 3.2
Resting 15 8.0 2.9latifolius. Fruit from Opuntia species were found in many stom-
ach contents in the eastern Cape (Seydack 1990). Herbage frac-
tion percentage means were higher in seasons with increased
rainfall (mainly spring). Prominent plant species foraged
included Blechnum punctulatum fronds and the foliage of mono-
cotyledonous herbs in the moist southern Cape and Aizoaceae
and Aloe in the more arid eastern Cape. In southern Cape for-
ests the subterranean plant part fraction was composed of 54.2
per cent fern rhizomes (Pteridium aquilinum), 38.9 per cent
tubers (notably Rhoicissus spp.), 5.7 per cent roots, and 1.1 per
cent corms. Fungi (primarily hypogeous Rhizopogon sp.) rep-
resented an important forage fraction in southern Cape forests
(Table 12.3). The subterranean fraction contributed dispro-
portionately to the diet during winter and spring when nutri-
ents and carbohydrate storage material had been translocated
to subterranean plant parts (notably in fern rhizomes). About
50 per cent of the total eastern Cape bushpig diet consisted of
subterranean plant parts (mainly Vitaceae tubers: Rhoicissus
and Cyphostemma species). Higher intake of vertebrate animal
matter was evident in eastern Cape bushpigs (Table 12.3). In
both regions the animal fraction was higher in females than for
males (Seydack 1990).Nutritional Ecology and Life-history Tactics
Suitable habitat for bushpigs in the Western Cape (South Africa)
primarily occurs in mesic southern Cape forests growing on
acidic, nutrient-poor soils and in eastern Cape xeric thickets
(Valley Bushveld) growing on nutrient-rich, base-rich soils.
Nitrogen, phosphorus, potassium, and cation exchange capac-
ity levels were found to be relatively low in southern Cape for-
est soils (Van Daalen 1984), but relatively high in soils of the
Valley Bushveld of the eastern Cape (Cowling 1982). The diet of
bushpigs from the nutrient-rich eastern Cape was characterized
by a relatively high nutrient to carbon ratio, while that in the
nutrient-poor southern Cape was found to have relatively high
carbon to nutrient ratios (Table 12.4).
The findings of McNab (1986) indicated that animals liv-
ing on the leaves of woody plants (folivores), grains, fruit,
and invertebrates (relatively low dietary NPK/carbon ratios)
had low weight-relative metabolic rates, whereas those feed-
ing on grasses, herbs, and vertebrates (relatively high dietary
NPK/carbon ratios) had relatively high basal metabolic rates.
According to a model linking nutritional ecology and life-
history tactics, relatively high dietary NPK/carbon ratios
underpin high metabolic turnover rates and prevalence of
reproductive over somatic investment, whereas relatively
low NPK/carbon ratios (carbon excess metabolism) are asso-
ciated with low metabolic turnover rates and prevalence of
somatic investment: size, longevity, energy storage (Seydack &
Bigalke 1992).
These findings are consistent with the postulates of a life-
history model presented by Seydack and Bigalke (1992) accord-
ing to which relatively high reproductive investment is expected
in the nutrient-rich eastern Cape, whereas relatively higher
somatic investment (size, energy storage, survival) would pre-
vail in the nutrient-poor southern Cape (Table 12.5)..01412:38:17