Download Du Toit Johan Truter 1988-002

by the
choice of
plants
the woody
browse components of their diets,
in
that
the
quality
of
their
diets
is
influenced by fibre, but secondary chemistry 1
However, giraffe
in the
1 for 24 hours, including
i feeding
time to
just three species of Acacia (Appendix Bl). It
could be
that giraffe
Acacia diet,
found
that
Colophoapermum
unpalatable and
almost VOX
1974 A).
are specifically adapted for an
but In on area adjacent to the KNP it was
a
mopane,
semi-evergreen woody
generally
plant,
made
up
of the giraffe diet in August (Hall-Martin,
Giraffe
in
another
area
of
the
Transvaal
lowveld were found to consistently ignore C. mopane due
ibility of
sms
that
giraffe
)pe with
npounds
preferred Acacia and Combretum
have
I
relatively high
when
they
have
ability has been reported for t
rhinoceros (Oiceros Mcortiis) in Damaralandi South West
Africa/Namibia
ILoutiL
et
al ,,
1987).
By
way
of
contract with smaller browsers, there is circumstantial
compounds produced
spread their
build-up of
by plants,
diets over
and Freeland and Jansen
numerous plants
specific toxins,
to prevent a
However, giraffe
in the
mid- dry season (July, observed for 24 hours, including
could be
: 7:
to the
that giraffe
availability of
that
preferred Acacia and Combret'
giraffe
have
the
faouitati'
ability has been reported for the desert-dweliing black
rhinoceros IDiceros bleornis) In Damnraland, South West
although forbs
species (e.g.
by Sell
that the
and woody
browse
giraffe) to select high quality foods
i1971) i but
optimum diet
missed by
Deist (1974). This was
preferred by
all ungulates
is
(Owen-Smithi 1908;
4.5 SUMMARY
Giraffe, kudu,
impala and
steenbok in the central KNP
all depend to a large degree on woody browse in the dry
season, However,
proportions ef
mean annual
they were
diets. Giraffe
woody browse
Kudu allocated
fed almost
of pods
differ
in
the
exclusively on
and flowers when available.
approximately a
forbs and
bulk, especially
browse made up the
in the dry season. Impala were mostly
the wet
about half
the diet
browse, Steenbok
but
third ot their feeding
creepers, Woody
grazers in
abundant,
to
throughout the year, including relatively
large proportions
time to
found
woody browse, forbs, and grass in theii
season, but in the mid- dry season
was composed
fed mainly
of forbs
on forbs
depended heavily
and woody
when they
on woody
were
brows-s and
Acacia tortills pods In the dry season.
The
dry
season
convergence
on woody
browse was
asso. 'ated with a tendency for giraffe, kudu and impala
to spend
of the
proportionally more
lower catena.
overlap increased
Although not
to a
time feedingin habitats
Mean dietary
peak in
diversity and diet
the late
dry season.
in the wet season, feeding preferences of
relatively
low,
sensitive than
and
smaller
giraffe
browsers
were
to
apparently
plant
less
secondary
compounds. Hence for ungulates it is clear that dietary
tolerance varies
more
closely
absolute diet quality does.
with
body
size
than
CHAPTER 5
BROWSER - WOODY PLANT INTERACTIONS
distribution, •bundance,
and chemical
noopesitif
By Crawley's (1!
in
browsing around
addressing
surface water?
two
questions:
Secondly, when giraffe
6.1 BROWSING,
ACACIA
TREES
AND
SOIL
AT
A
SAVANNA
WATERIIOLE
5.1.1 Introduction
6.1.1.1 Browning and plant compensation
Mcitaughton (1984:881) proposed that "individual grazers
obtain a
foraging advantage
because of
the greater
by membership
forege
yield
per
in a
herd
bite
from
grazing Inwns compared with lightly grazed vegetation."
A grazing
lawn is
a patch
of dense,
closely
grazed
grass that is more productive and nutritious than tall,
sparser grass
growing on the lightly grazed periphery.
McNaughton {op. clt.)
suggests that
the dense, highly
branched canopy surface of heavily browsed woody plants
is
analogous
browsing has
production in
Sweden,
to
been
grazing
to
the Serengeti
browsing
{fletuia spp,)
a
found
by
noose
can induce
lawn,
Indeed,
stimulate
(Pellow,
(A2oes
giraffe
Acacia
19836)
alces)
shoot
and
on
in
birch
compensatory growth which is
more palatable than foliage on unbrowsed plants (Danell
et. si.,
section I
grazing
1985; Danell
and Huss-Daneli, 1986). In this
consider the
lawn
hypothesis
Acacia nigrescens,
applicability of
to
browsing
HcNaughton's
ruminants
and
one of the principal food plants of
browsers In the central KNP.
4
:r
In the
Solerocai-ya birrea / Ac&ci&
landscape
of
the
central
A. nigrescent trees
but are
KNP
predominate on
relatively less
nigrescent i
(Gertenbach,
1983),
the basalt
plains
abundant near
surface
water
(Codd, 1931), where their canopies are typically pruned
by impala
from below
observations). This
and giraffe from above (personal
pruning results in a clear browse-
line beneath a dense, highly branched canopy, which may
be sculptured
as is
into a cone, spf ’■e, or hour-glass shape
characteristic of
(Sinclair and
by
giraffe
Norton-Griffiths, 1979; Pellew,
severe
browsing
1984h;
Coe and Coe, 2987). The browse-line is caused by impair
which are
mixed feeders
turno.-er (Fairall
seldom found
with a
more than
a few
water (Young,
1972; this
maintained by
many impala
from woody
high rate
of
water
and Klein, 1984), and in the KNP are
plants in
giraffe exerting
kilometres from surface
study), The browse-line
each taking a little
is
browse
a localised area. The reason for
such
a
high
browsing
pressure
at
waterholes is rather less apparent however.
Unlike grass,
woody foliage
water content
through the
savanna browsers
water
(Taylor,
Giraffe, kudu,
available,
but
high preformed
which
enables
to be
largely independent of surface
1969;
Western,
and steenbok
not
during droughts).
retains a
dry season,
by
This is
1976;
do drink
necessity
Louw,
when
(except
evident from
1984).
water
is
obviously
the fact that
during the
out of
two dry tjosona of this study, at least two
the four
kudu cow
groups monitored
by
radio
telemetry (Chapter 3) did not visit surface water once.
Neither did
the two
giraffe were
often
radio-collared steenbok. Although
often observed
observed
feeding
drinking, they
around
waterholes
were also
and
then
moving off without drinking. During a dry season in the
East African Amboaeli ecosystem, the highest density of
giraffe was
found 30-36 km from water, while zebra and
wildebeest
were
concentrated
5-10 km
from
water
(Western, 1976).
Since browsers
ore largely
water-independent it is to
be expected that they should actively avoid waterholes.
The central
of lions
KNP supports
in Africa
distribution of
one of the highest censities
(± 13 adults per 100 km2 ), and the
pride core areas is closely related to
the distribution of waterholes (Smuts, 1982). Lions are
attracted to
waterholes by
mainly wildebeest
by lions
and zebra,
as they
my observations
a high
biomass
of
prey,
which are often ambushed
come to drink (Schaller, 1972). From
it is
clear that
kudu in the central
KNP are sensitive to the predation risk associated with
waterholsg, which they do actively avoid, This does not
app'y for
giraffe
however.
sculptured A. nigrescens
To
tl.a
canopies are
contrary,
dense
evidence of the
fact that giraffe are actually attracted to waterholes,
Because giraffe
to visit
risk a
high predation threat in order
waterholea that
from, especially
explanation is
Since the
in the
they do
not need
wet season,
that they
to
the most
drink
likely
are attracted there by food.
browse (A. nigrescens
foliage) that giraffe
spend most time feeding on at waterholea is equally (or
more) abundant
elsewhere, this suggests that browse at
waterholea might
Hence this
be
more
palatable
investigation
hypothesis that
was
than
designed
severe browsing
elsewhere.
to
test
the
by giraffe and impala
results in compensatory growth of enhanced palatability
in A . nigrescens
patches that
are frequented
by both
species.
5.1,1.2 Browsing and Acacia savanna e/yasBica
In
African
feeding
semi-arid
by
savanna
concentrations
ecosystems,
of
selective
indigenous
large
herbivores can profoundly influence vegetation dynamics
(Walker, 1986).
overstocking
In areas
causes
of subsistence
encroachment
of
paatoralism,
less
preferred
woody plants, soil erosion, and dea: '.vLcation (Walker
et al ■,
1981; du
1986). The
dynamics is
196B[
Sweet
and
Mphinyane,
browsing on aomi-arid savanna
Inextricably linked with tho influences of
Boil moisture,
1882; Pellew,
impact of
Toifc,
influence of
grazing and
1983a), and
fire (Walker and Noy-Meir,
in conservation
elephants (Loxodonta
areas
Africans) is
a
the
major
'ogetation dynamics,
Large
browsing
and that,
is the
concern of this
herbivory could
food plants
lead to replacement of preferred woody
by better
defended species
concentration points,
such as
at
waberholes.
herbivore
In
boreal
forests it has been found that herbivore-driven changes
in woody
plant community
with reduced
Chapin,
rates of
1988).
In
possibility of
this
cycling
section
I
be associated
(Bryant
and
consider
the
a similar effect occurring in a savanna
ecosystem, where
5.1.2
structure may
nutrient,
herbivores concentrate around surface
Methods
i. Experimental design
Three sites were chosen on the upper catena on basaltic
clay soil in the Sclerocarya birrea / Acacia nigrescene
savanna landscape
of the
central
KNP
(described
by
Gertenbaeh, 19B3).
One site was at a seasonal watorhole that had formed in
a shallow depression enlarged by wallowing elephant and
buffalo.
The
heavily
grazed
immediately about
this waterhole
Acacia
and
tcrtilis
trees, Five
both
species
severely
mature trees
at
this
individually labelled.
and
was
pruned
trampled
area
vegetated
with
A. nigrescena
were chosen
at random
site,
each
and
tree
from
was
On each tree ten growing shoots
were marked
with individually
numbered plastic
tags,
which were tied with string approximately 60 cm in from
the canopy surface, The tags were distributed all round
the canopy
from the
surface, The
branches) distal
using a
length
against a
lower browse-line
length
of
shoot
to each
of
the
upper
all
side-
tag was
string
ruler, Tagging
to
(including
which
was done
precisely
measured
was
compared
then
in mid- September,
just before the spring flush,
A second site, the A. nigr-iacena control site, was in a
monospecific
stand
nlgrescens trees
3 km from
of
mature,
lightly
browsed
A.
7 km from the waterhole and more than
alternative water.
The herb
layer at
this
site, which supported a relatively low density of large
herbivores, consisted
mainly of
tall, lightly
grazed
Themada triandra grass. Here, five trees were chosen at
random, and
way (and
A third
individually marked and taggeo in the same
during the
site, the
monospecific stand
ranger
station,
herbivores visited
due to
the
nevertheless
same week)
as at
the
waterhole
A. tortilis control
site, was in a
of
the
4 km
A. tortilis
from
this site
disturbance
of
representative
the
at
relatively
human
of
Tshokwane
Waterhole,
activity,
the
Large
infrequently
It
was
surrounding
A , tortilis savanna vegetation, which is heavily grazed
rampled
by large
herbivoj
growing season),
The proportion of tagged shoots showing signs of recent
lite,
during
proportions of browsed shoots pej
-vr
Methods of
analysis were
those described by Bryant _et
£j (1985) and outlined in this thesis in Chapter 4.
Sc '1 samples were collected beneath each marked tree at
each site
by scraping away surface litter and removing
a spade-full
places (at
of soil
canopy, 1 o
well mix.J
depth of
of
the
± 10 cm
compass)
at four
beneath
the
out from the stem. These four samples were
and one sub-sample was placed in a labelled
paper packet.
of soil
to a
each point
This resulted
collected from
each site.
These were
temperature in
were analysed
air-dried
the USA
tree species
and
stored
until analysed.
for total
ammonium nitrogen,
in five replicate samples
beneath each
nitrogen,
at
Soil
nitrate
at
low
samples
nitrogen,
total phosphorus, and water soluble
phosphorus. Total nitrogen and phosphorus were analysed
by the
methods described
outlined in
this thesis
by Bryant
_et si
in Chapter
4.
(1985) and
Soil
nitrate
(NOa), ammonium (NHO, and water soluble phosphorus (P)
were assayed
1982): NOg
by
standard
agronomic
and NH<
were extracted
soil with
75 ml of
2-normal KC1;
extracted
overnight
distilled deionized
extracts were
autoanalyser.
from
water
2-3 g
(7 ml
methods
(Black,
for 1 hr from 15 g
water soluble P was
soil
Hz0/g
with
soil).
double­
These
analysed colorimetrically on a Technicon
iv.
Assumptions
This
experiment
■
was
designed
to
compare
browsing
!
and
i
local soil nutrients available to specific trees of two
'
pressure, net
shoot
Acacia species
It is
leaf
chemistry,
across a gradient of herbivore density.
|
not assumed that measurements from each site are
|
representative of
the
extension.
the regions
experimental
pseudoreplication
differences
design
(Hurlbert,
(i.e.
differences) were
in which they occur, as
would
then
1984).
excluding
flawed
Intrinsic
by
site
herbivory-induced
,
f
in the
I
and soil type, and in the same position
|
at the
the
1
top of
control sites)
catenary
choosing sites
j
{
same landscape
furthest distance
minimized by
be
drainage
between sites
was
sequence.
10 km
(the
The
two
and so rainfall differences are assumed
to be negligible.
6.1.3
►
Results (Table 6.1)
i . Browsing pressure
The
overall
conclusion
of
the
Student-Newman-Keuls
(SNK) multiple range test (a » 0.06) was as follows:
BPven ^ BPv a s + BPo an « BPo a e ,
.here BP
is browsing
pressure on tree samples denoted
Tibia 5.1, Flint i M soil data frgi mte r h o l i M d control sites,
firubli
f w a u l H 1} 8.6,1 per v i r U b l a per site
A, E ortlh
Control
Browsed shoots'
Het sboot e Uenslon
<,»]gresceits
D iff
0,60
mt a r h o l s
I1.M
Diff
(
Uaterhole
30.TS
Oiff
)
Control
J.M
ns
leaf tannin"
Issf total H
(t in mssI
leaf total P
H dry iiesl
Soil total N
Soil nitrate N
18.6061
(1581
Z.OO
Soil JMOBiUJ! «
Soil total P
Sofl soluble f
luir'l
‘Ciflpiritors Inolcite differences deteryined by the Student-Hems-Keiilf m l t l p l e rinse
test (e : 0,06),
'Pereantise of w r W shoots v U h l n eech saeple of trees that i h o m d signs of recent
browsing, avaraged over « quarterly Inspections,
’A b s o rbmce value obtained In tue proanthocjmldlfi assey.
the
waterhole
heavily
site
than
two control sil
tortilla
11, Shoot
where NSE
is net
previously
described), ranked
from
the right. Sample
46. Although
shoots died
still alive after
The comparison
was greater
shows that
net annual
in A. tortllis
waterhole and
control sites,
annual ahoot
extension did
shoot extension
than A. nigrascens at both
Within each species, net
not
differ
significantly
between waterhole
and control
sites. This
important, as
shows
despite
almost 10
it
times more
waterhole site
per shoot
achieved a
equivalent to
achieve this,
browsed
A. nitfrescens
exceptionally high
finding is
being
browsed
severely, A. nlgrescens
order to
and to
that
at
the
net annual growth increment
that at
the control site. In
compensatory growth in heavily
trees
must
have
been
to compensate for continual removal
achieve a net annual growth increment per shoot
equivalent to that of lightly browsed trees.
iii. Leaf chemistry (Table 6.2)
Leaves on
heavily browsed
A. nigpescens trees
at the
waterhole were significantly lower in condensed tannin,
and higher in total nitrogen and total phosphorus, than
leaves on any of the other tree samples.
Iv, Soil chemistry (Table 5.3)
a). Soil
total
A. nlgrescens
nitrogen
control
A, tortills control
intermediate.
was
site
situ. The
highest
and
lowest
at
the
at
the
waterhole site
was
TabU 6.2. Leaf chemistry comparisons across Acacia species
and sampling sites.
Leaf chemistry
variable
grouping1
Sample2
Condensed
tannin
A. nigrescens control
tortilla control
tortilis waterhole
A. nigrescens waterhole
nitrogen
A. nigrescens waterhole
nigrescens control
tortilla waterhole
A. tortilla control
phosphorus
b
b
A. nigrescens waterhole
nigrescens control
tortilis waterhole
A. tortilis control
‘Samples with the same letter are not significantly
different {o = 0,06).
*Ranked by mean value of each chemical variable, with the
sample with the highest mean value at the top in each case.
nigrescens waterhole
value of each cheuical variable, with the
highest mean value at the top in each caae.
I
f
b). Soil
total
phosphorus
was
waterhole and
lowest at
site.
A. nigrescens
The
intermediate. This
the
was
highest
at
A. tortilis
control
the
same
the
control
site
was
conclusion
for
nitrate nitrogen and ammonium nitrogen.
c ). Water
soluble phosphorus was higher in soil at
the waterhole than at the two control sites.
d ). In
site
all comparisons,
had
e). At
the
lowest
the waterhole
beneath
the
of
site, soil
A. nigrescens
significantly
A. tortilla
levels
different
soil
nutrient
canopies
to
control
nutrients
levels
were
those
not
beneath
A. tortiiis canopies in all comparisons,
v,
Variation
in
leaf
nutrients
with
respect
to
variations in soil nutrients and browsing pressure
a). In both Acacia species leaf X and P levels were
not significantly
correlated with
soil
N
and
P
levels (P > 0.05 in all cases).
b). Browsing pressure on A. nigrescens Was strongly
positively
correlated
with
leaf
total
nitrogen
nitrogen content (percent dry
ge percentage of marked ahoota that
tor trees at control (triangles! and
.rr
nm) in the proanthooyai
content (Fig- 5.1; r = 0.80, P
negatively correlated
0.01, n = 10), and
with leaf
condensed
tannin
content (Fig. 5.2; r = -0.70, P < 0.05, n = 10).
c). Browsing
pressure
on
was
A. tortllis
not
correlated with any of the leaf chemistry variables
assayed (P > 0.05 In all cases),
6.1.4
Discussion
6.1.4.1
In a
at
Browsing and plant compensation
mixed stand
a
seasonal
significantly
of Acacia tortilis and A. nlgrescens
waterhole,
higher
on
A. tortilis. Browsing
also very
To
the waterhole,
pressure
on
the
on
A. nigrescens
was
waterhole
tissue
was
than
lost
than
to
at
a
browsers,
growth occurred in A, nigrescens at
ao that
not significantly
control trees.
at
replace
compensatory shoot
foliage on
pressure
much higher
control site.
browsing
A, nlgrescens
net annual shoot extension wee
less than that among lightly browsed
Furthermore, the nutritional quality of
severely browsed
significantly higher
condensed tannin)
<4. nlgrescens
trees
was
(higher in nutrients and lower in
than
that
of
foliage
on
lightly
browsed trees.
The difference between A. tortilis and A. nlgrescens in
expected from
the hit
Firstly, it
phosphoi
A. nigresoens leaf
nutrients
should
also
have
been
higher at the waterhole than at the control sites. This
was not
the case,
nitrogen
at
the
significantly from
site, which
all three
however, In
waterhole
that
fact, A. tortilts leaf
site
at
the
did
not
differ
control
A. tartllis
had the lowest soil nutrient levels out of
sites. Finally,
cannot account
waterhole
for the
and
soil
control
A. nigreacens leaf
nutrient
differences
significant difference between
sites
with
respect
to
condensed tannin levels, as no such
difference was detected for A. tortilis.
An
alternative
induces a
hypothesis
is
that
physiological response
severe
browsing
in some woody plants
that increases palatability, leading to a feedback loop
of further
browsing. The
mechanics of
this
feedback
loop (refer to Fig. 5.31 are outlined as follows:
Browsing ruminants
even steenbok
during feeding
1985; personal
pruning (step
response quite
such aa
often bite
giraffe, kudu,
off
(Dunham, 1980;
or damage
Pellew, 1984ej
observations). This
1 ) which
different
impala and
shoot
is
ends
Cooper,
equivalent
to
induces a plant physiological
to
that induced
by
severe
defoliation such as by insects (Dane11 and Huss-Danell,
1985; Bryant
et al,,
in
press). Pruning
the
shoot
system of mature woody plants reverses ageing (step 2),
reducing
between-shoot
competition
for
nutrients
Figure 5.3. Cauee-and-eftect model of woody plant chemistry changes
induced by severe browsing, showing positive effects on palatability
that Induce further browsing. Arrows between boxes indicate positive
effects unless marked (-). Small arrows within boxes indicate
directions of change.
(Moorby and
Wareing, 1963).
concentrations of
3)i stimulating
appears that
The result
nutrients in
growth (step
the pruning
is
increased
remaining shoots {step
4), Prom
this study
effect, widely
to
the
it
employed
in
advantage
of
orchard management,
also works
browsing ruminants.
Evidence is compensatory growth of
shoots and significantly higher levels of leaf nitrogen
and
phosphorus
relative to
in
severely
less pruned
pruned
A. nigreacens
A. nigreacens and A, tortllia
(Table B.l). Furthermore, carbohydrate demands incurred
by
compensatory
limitation
growth
(step
(step
6)
metabolite synthesis
of
5)
cause
substrate
carbon-based
(Bryant et
secondary
a!., 1983; Danell and
Huss-Danell, 1686;
Bryant et al., 1987; Bryant et al,,
in
leaf
press)i
Hence
heavily browsed
significantly
condenses
A, nigreacens at
reduced
browsed plants
at the
(halved)
tannin
.he
levels
waterhole
relative
to
in
were
lightly
control site (Table 1). Reduced
chemical defence and increased shoot nutrients (steps 6
and 3) increase the palatability (step 7) of most woody
plants (Bryant
et al.,
1983; Danell
and Huss-Danell,
1986; Cooper and Owen-Smith, 1986; Cooper et al., 1988;
Bryant et
thereby
al.,
in
attracting
press;
this
increased
study,
Chapter
browsing
4),
pressure
(feedback loop to step 1).
For the
above cause-and-effect
system to be initiated
and maintained, it requires browsing pressure to become
focused
on
a
suggest that
which
localised
this focus
ioipala
are
requirements,
height range.
of
attracted
and
A. nigrescens to
patch
where
the
4. nigrescens.
I
is provided by waterfioles, to
for
they
upper
limit
Even moderate
their
water
severely
browse
of their
feeding
browsing by giraffe would
then raise the browsing pressure on these patches above
the "background"
produce
the
level.
pruning
palatability, then
If
this
effect
was sufficient
leading
more giraffe
to
to
increased
would be attracted to
these patches and the browsing feedback loop would come
into effect.
Stimulation of
been
Acacia shoot production by browsing has
demonstrated
giraffe (Pellew,
1987). Pellew
induced
by
Acacia
browse
quality.
Hence
considered analagous
to the
which modify
also Chapter
is to
in a
6, section
consider the
that this
could be
agents
browsing not
production,
by browsing
individual graaers
(Teague,
indicates that
shoot
concentrated feeding
in grazers,
with
goats
Dyer, 1980; McNaughton, 1986).
this study
stimulates
experiments
domestic
plant-frowth-promoting:
al., 1972;
Evidence from
promotes
controlled
(op. oit.) suggests
salivary
(Reardon et
only
in
1983b) and
the
but
effects
ruminants
could
also
of
be
effects of gregariousness
the sward
to the bene.it of
herd (McNaughton,
1984;
see
6,9). The next important step
degree to
which A, nigroscens can
continue to compensate for tissue loss, and by so doing
maintain the browsing system.
5.1.4.2
Browsing and Acacia savanna dynamics
At the
waterhole
abundant than
site,
in the
A. nigrescens
savanna,
A. nigreacens was
pruning
the previous
that compensatory
severe
being
competitors,
such
more
browsers
on
the palatability of
Here I
to a feedback
propose
eventually
replaced
as
on
than
section it was suggested
browsing
A, nigreacens
was
severe
A. nigreacens, leading
further browsing.
of
by
growth enhances
severely browsed
cycle
A. tortilis
significantly more
A. toctilts. In
loop of
where
surrounding Sclerocarya bircea /
by
that
less
A, tortilis,
this
results
in
preferred
where
large
herbivores concentrate around surface water.
Whether herbivory
so at
may actually
what level,
Wiegert,
1976;
HcNaughton,
found that
are issues
HcNeughton,
1986;
Belsky,
even under
Serengeti ecosystem,
grazer-adapted
definitions of
(1984b)
benefit plants, and if
of hot debate (Owen and
1983;
1987).
very
1986!
(1979)
intense
productivity
grasses
Belsky,
McNaughton
to
grazing
was
which
in
maintained
the
by
conventional
overgrazing may be inapplicable, Pellew
suggests
that
Acacia
species
are
able
to
withstand severe browsing as the result of evolutionary
e
herblvory depresses plant fecundity
(Crawley,
ippressed
by severe
browsing (Coe and Coe, 19B7).
defended against browsing Istructurally
leaves
(particularly
palatable indehiscent
A. tortilla),
pods. By
and
produce
contrast A . nlgrescens
and Owen-Smith, 1986; Pellew, 19846), while consumption
of pods facilitates seed dispersal and reduces the risk
of infestation by seed-boring bruchid beetles (reviewed
by Coo
and Coe,
1: -7), It is not surprising then that
density where
sakened
(Codd,
the grass layer has be<
Mphinyane, 1986).
the
KNP
Indeed, one
(Wolhuter,
D. uinerea in
u948)
of the first rangers in
ascribes
t.he
spread
of
the southern KNP to population increases
among ruminants (particularly irapala, but alio kudu and
giraffe) after
the rinderpest epizootic and subsequent
protection from hunting.
An alternative
that
to the
A. tortilis
herbivory hypothesis
and
nutrient-rich soils,
and
because of
dung.
is not
replace
surface water
This
investigation
are
P, clnerea
could
adapted
A. nigeescens
be
for
near
local enrichment of soils by
supported by
however,which found
the
present
that soils
at the
d . tortilis control site had the lowest nutrient levels
of all
three sites
nitrogen
control
was
site
alternative
sampled. Furthermore,
In fact
than
could
higher
at
be
the
that
A. nigrescens
where
surface, such
as near
waterhole and
control sites
catena though,
the
and the
at the
total
waterhole.
A
second
out-corapetes
A. tortills
water-table
is
near
riverlines. A. tortiiis
were at
soil
X . nigrescens
the top
the
at the
of
the
small seasonal waterhole would
have bed an insignificant influence on soil moisture in
the surrounding
elephants are
near su. "ice
expect
area. Thirdly, it could be argued that
the prime
agents of vegetation
change
water. This aey be so, but then one would
A. tortllis
A. nigresaens, because
to
be
for
affected
example
in
as
Lake
much
as
Hanyara
National Park,
Tanzania,
it
is
elephant
damage
to
A. toccllls that
is causing
most concern (Laws, 1970;
Mwaiyosi, 1987).
Finally it
must be
heavy grazing
and trampling
recognised
that
remove the fuel load near
surface water. Consequently reduced burning could cause
species changes
of herbivory,
in woody vegetation as a distal effect
but the
effects of
reduced burning and
herbivory are difficult to separate.
Considering
possible
herbivory remains
establishment of
near surface
severe
selective
A. tortilla f
D. cinerea thorn-scrub
water in the central KNP. Associated with
this thorn-scrub
such as
alternatives,
the most likely factor promoting the
i/aytenus
(Coddi 1961;
are various sclerophyllous evergreens
seneg&lensis
van Wyk,
These species
1984;
and
Euclea
personal
divinorun
observations).
are generally low-preference food plants
to browsins
ruminants (Chapter 4). I suggest that this
woody plant
association
could
develop
where
selective browsing
reduces the
fitness
of
species
A. nigrescons.
such
changes occur
where
as
in the
selective
inherently
herbivory
sclerophyllous evergreens
litter
produced
by
favours
encroachment
chemically
(Bryant and
small amount
mineralises slowly
vegetation
boreal forests of North America,
slow-growing
The relatively
Similar
severe
preferred
these
(Lewis and
of
defended
Chapin,
1986).
of fibrous, tanniniferous
plants
decomposes
and
Starkey, 19681 Swift et
i.
a.1., .979),
thus impeding nutrient cycling (Bryant and
Chapin, 1996).
A
potentially
important
investigation is
finding
that total
of
the
present
soil nitrogen was highest
at the lightly browsed and graaed A. nSgresaens control
site, intermediate at the waterbole site, and lowest at
the
control
A. tortiiis
Nwaswitsontso River,
severe berbivory
be replicated
site.
the latter
Being
near
the
site had a history of
and trampling. Sampling would have to
using more
sites to
determine if total
soil nutrient levels are always higher in A. nigrescent
savanna
than
around
savanna. Nevertheless
exact reverse
(1984) for
woterholea
the pattern
of that
or
in
A. tortilis
I describe
described by
is
Hatten and
the
Smart
the effects of long-term exclusion of large
herbivores on
soil nutrient
National Park,
destruction
Uganda.
of
trees
status in Murchison Falls
Weir
of
(1971)
found
certain
extensive
species
around
artificial pans
in Hankie National Park, Rhodesia (nov
Zimbabwe). flung
accumulated at
these pane, where soil
phosphorus levels
were high, but the phosphorus levels
declined steadily
outwards for
the woodland
from ffier'e
fringes, and
study,
the
approximately 4 km
to
then increased again, Apart
influence
of
African
large
herbivores on nutrient distribution, redistribution and
cycling has
On purely
received little attention (Gumming, 1982).
theoretical grounds,
Botkin et
al,
(1981)
suggested that large herbivores may be important in the
maintenance of
but this
are
a nutrient
is mainly
susceptible
pool near the soil surface,
in high rainfall areas where soils
to
leaching.
These
authors
also
acknowledge that cycling of nitrogen through herbivores
could
in
fact
increase
nutrient
losses
via
volatilization of ammonia from urine and faeces.
I suggest
that severe
selective herbivory in ariu and
semi-arid ecosystems could retard nutrient cycling near
surface water,
resulting in
a local
soil
decline in
fertility. The process by which this could occur (refer
to Fig. 5.4) is as follows:
Where browsing
heavily on
growth of
ruminants concentrate
A. nigresaens, which
enhanced
browsing (this
fall from
removal of
and
compaction,
important
represents
nitrogen,
the herb
trampling,
'.'his
as
a
the
organic
through
nitrification replenishes
(Hatten and
in
mineralizable
which
ammonia-nitrogen
which
decline
and
attracting
further
browsing reduces litter
A. nigrescens. Litter
reduced by
grazing
palatability,
study). Severe
they impact most
produces compensatory
production is further
layer through
also
litter
matter
of
of
ammonification
the plant-available
nifcrate-nitrogen
soil
production
content
resource
severe
causes
is
soil
organic
and
pool of
respectively
Smart, 1984). A. nigrescens is replaced by
Enhanced
A side d g r e s c m
U ls tib llit*
S e n re se lK tiM
T tro n in j
depletion of
herbaceous
Deduced ra te of
n irtr/e st C fd fn j?
^ r v lif e n tlo n o f thorn-scruh
and aderophyilous evergreens
Notwithstanding the
limited
a significant infit
•lent cycling ir
particular attention
ig
The diet of giraffe in the
(Hall-Martin, 1974a;
t.
;udy period
during which flowering
>red 7, and scores for other months
relative to
this, This
method provided a
convenient 1 •elative flowering index" .
feeding
on
giraffe, kudu, impala,
in
Chapter
4.
January 1985
to
For
this
December
5.2.3 Results
i.
Phenology
of
flowering
A. tortilis
Flowering in
A. nigresi
short period
in the
July to
li
September 1981
tmber 1986, a
t. tortilis v
less ret ular,
peaking :
: varying per;
Flowering in
1986 (Fig.
both species
6,6), probably
I on rainfall; from
1986 was weaker than
of
lower
rainfall
i
during the
wet season
of 1985/86
relative to 1984/86
(439 mm c.f. 809 mm).
11. Flower consumption by browsers
Giraffe were
the only
woody plants
constituted an
browsers for
which flowers
important food
of
resource,
During September
in both years over which feeding data
were
(1986
collected
A. nirfreseens flowers
were available
feeding time
and
198G),
in large
giraffe
consumed
quantities while
they
(Figi 5.5). This accounted for 23,6% of
(out
of
11,6 hours of observation time spread over 6 days),
recorded during
September 1986
and
IP.3% in
September1986 (out
6 days).
The lowervalue for 198$ corresponds with the
weaker
flowering
A. tortills flower
when flowers
for 4.2*
A. nigresoens
consumption did
were available
of giraffe
1S86 (17.5
of
of 16.5 hours spread over
that
year.
always
occur
(Fig, 6.5).
feeding time
hour» spread
not
over 6
It accounted
recorded in January
days), and
29.SX
in
March 1&86 (out of 6.3 hours spread over 2 days). Other
flowers
making
giraffe diet
and Combretum
Flowers making
Maytenus
a
significant
were Acacia
contribution
gerrardii in
to
the
the wet season
hereroense in the dry season (Fig. 6.6),
a minor
senegalensia,
paniculatum,
,c hotia
mespiJiformis,
and
contribution to
the diet were
M. heteropkylla,
Combretua
brachypetaliaj
Dlospyros
Kigelia
africana
(Appendix
Bl).
These plants
bloom in the c
during September and accounted for 3.4% of feeding ti
for that
flowers
month, averaged
eaten
sengalenals,
by
kudu
over the
two
years.
Ott
incJ
M. heterophyi
and Combcetua mossambtcense (Appendix B2).
Impala and
steenhok were
flowers of
any woody
not observed
attractive
re,
ntal to
trong
feeding on the
plaiits, these being mainly above
If
the reproductive
selection
for
food
giraffe
resource
feeding
success of
defence
to
was
flowering
against
flower
Consequently,
giraffe might stand nibbling at A, t<
is unlikely that much damage is done
m
s
"bottle-brush") inflores
(Hall-Martin, 1974a),
jpinesoent
although thi
stipules
sarly all
the species
with capitate
well armed with apinescent stipules.
have pals
sith capitate
•phological
if species
inflorescences
have
differences
between
with
capitate
and
bright
the
spicate
4
furrows were
not
found
on
any
pollen
grains
from
African species with spicate Inflorescences.
Acacia pollination
is attributed
mainly
to
insects,
although the breeding systems and pollinating agents of
many African
Coe and
species remain
unexplained (Ross,
1979;
Coe, 1981). The pollen grains are too large to
be dispersed
by
wind
(Coetzee,
conspicuous aggregations
some species,
all) African
and male
of insects
most African
low pod;flower
1955),
and
!
on the flowers of
;
Acacias have
ratio (Rosa,
a remarkably
,
1979). Many (and possibly
;
Acacia inflorescences consist of bisexual
flowers
in
(op. cit.) suggests
varying
proportions,
that sterile
or male
and
Ross
flowers are
possibly the functional equivalents of petals, with the
production of
vast quantities
of blossom
creating
light
of
the
above,
A. nigresoens flowers
may seem.
The removal
he fertilized
reproductive success
flower mass
and necks.
telemetry
on
j
|
of flowers that are unlikely to
j
have little
of the
though, giraffe
large quantities
of pollen
Giraffe are
on
adult
^
is much leas destructive than it
anyway will
feeding
)
a
visual attractant to pollinating agents,
In
:
despite
plant. By
are
by
giraffe
effect on
the
1
feeding in the
;
certain
to
collect
highly mobile, and using radio
females
:
in the hair of their beads
I
have
recorded
daily
movements of up to 20 km, while one radio-collared bull
i
itudy. Chapter 4),
flowering
that
giraffe
(personal observations).
>. By contrast it would
by
pollen di
t.:.1
f
ungulates,
preventing
6.3 SUMMARY
6.3.1
At a
Browsing and waterholes
seasonal vaterhcle, A- nigresaens trees were more
heavily
A. ■
b'-owsed
than
trees.
tills
! nlsrescens had
Jpvels of
browsed
condensed tannin
that
intershoot
compensatory
severe
browse
generating a
finer-leafed
heavily
for
by
browsed
browsers
lightly
It
is
reduces
promoting
demands
carbon-based
attracts
biowsing -
of
site.
nutrients,
The result
that
suggest that
foliage
control
Carbohydrate
reduce
metabolite synthesis.
palatable
a
pruning
growth.
growth
than
at
competition
compensatory
and
of
higher Irvels of nutrients and lower
A. nigreacena
suggested
loop, I
thornier
Foliage
of
secondary
is a patch of highly
further
browsing,
compensatory growth
feedback
this is analogous to the grazing
lawn phenomenon.
In the
felerocarya birrea
landscape of
the central
d . iortilia and
Dichrostachys cinerea
heavily grazed
water.
against
These
/ xcscin nigreacena savanna
JINP, there is a tendency for
and
trnmple< patches
species
herbivory,
propagation, and
selective browsing
arc
have
hence
physically
to dominate
around
well
he rbivore-adapted
are
successful
reduces the
in
surface
defended
means
where
of
severe
fitness of competitors
i
such as
A. nigreacens. Associated
0. cinerea
thornscrub
are
evergreens.
I
quantity of
litter produced
impede
suggest
nutrient
water points.
that
cycling,
relatively lower
with A. tortiJis
various
the
/
sclerophyllous
lower
quality
and
by this association could
and
ultimately
soil fertility
in
the
lead
to
vicinity
of
The management implications of this need
consideration
in
the
planning
of
artificial
waterpoints.
6.3.2
Giraffe and Acacia nigrescens flowers
Flowers of A. nigresceas are an important food resource
to
giraffe
in
the
late
necessarily deleterious
dry
season.
This
is
not
to the plant, however. Most or
all African Acacias have very low pod:flower ratios, as
many flowers are sterile. Such factors as inflorescence
colour and structure, pollen characteristics, and thorn
structure indicate
could be
that one
pollinated by
flowering in
A. nlgrescens, and
between A. nigcesoens
suggest that
species.
group of
ungulates.
and giraffe
Atrican Acacias
The
phenology
of
the close association
in the central KNP,
giraffe could be a pollen vector for this
CHAPTER 0
FINAL DISCUSSION
6.1 Overview
The questions
address the
posed at
issues of
the beginning
of this
thesis
how syntopic browsing ruminants
use shared food resources, how preferences for habitats
and food plants differ, and. some of the implications of
resource use
on resource
conceptual framework
addressed was
guild. In
use by
abundance and
within which
that of
quality.
these
issues
resource partitioning
The
were
within a
this chapter I synthesise my findings on the
browsers
of
habitats
and
food
plants,
and
discuss thase with respect to the resource partitioning
hypotheses presented
conclusions
on
in the introduction, I present my
resource
browsing ruminant
partitioning
guild, consider
the
within
the
Importance
of
interspecific competition to the guild’s structure, and
compare the
assess the
browsing and
grazing guilds.
Finally,
I
value of the guild approach and suggest how
future research
could build
on the
results
of
this
6.2 The use of habitats
My findings
steenbok
confirm that
use
communities)
seasonal cycle
for ungulates
giraffe,
different
with
different
kudu,
habitats
impala
and
(vegetation
intensities
over
the
as a whole (section 3.3.3), as proposed
by Lamprey
(1963)
and
McNaughton
and
>ith respect
of forba and woody forage types that they
Hofmann and
Stewart 11972)
ruminants (“selectors
separated African browsing
of juicy, concentrated herbage”)
into (a) "tree and shrub foliage eaters" and (b) "fruit
and dicot (tree, shrub or forb) foliage selectors", The
former ^roup
group
included giraffe
included
steenbok,
duiker
which
was
and kudu and the latter
klipspringer,
classified
intermediate feeder.
the basis
and
with
This classification
of s'--»-ach
but
impala
not
as
an
was made
on
structure and field observations
published .
■. My findings on dist composition
(section 4.
al inconsistencies with Hofmann and
Stewart’s classification.
giraffe allocated
time to
Of the four species studied,
the highest
fruits and
proportion
flowers, which
of
feeding
would warrant
its
inclusion in group (b) above. Steenbok hardly grazed at
all (see
also Cohen,
1976), feeding
on forbs,
foliage and
Acacia tortilis
pods,
which
warrant itn
inclusion (with
giraffe) in
woody
would
also
gr-up (b) of
Hofmann and Stewart’s classification.
The
above
examples
separating ungulate
illustrate
species
the
into
difficulties
categories
on
of
the
basis of
diet. If browser species are to be classified
by diet,
I suggest that they be graded on the basis of
the relative proportions of herbaceous and woody browse
that they
ualleri)
consume. For
feed
almost
example, gerenuk
exclusively
on
llitocranius
woody
browse
i
(Leuthold, 1970),
to giraffe
as woody
and so
than are
are trophically more similar
kudu, which feed on forbs as well
browse. Block
rhinoceros also
feed on
both
forbs and woody browse (Goddard, 1970), and so in terms
of their
food requirements
they are
more similar
to
kudu than to giraffe and gerenuk. Such similarities and
distinctions
were
Stewart, who
placed giraffe,
some category
did not
not
considered
("tree and
consider black
by
kudu and
shrub foliage
rhinoceros as
Hofmann
and
gerenuk in the
eaters"), and
this species is
not a ruminant.
6.3.2 Seasonality
Among kudu,
impala and
steenbok,
the
proportion
of
woody browse in the diet rose sharply in the dry season
to
compensate
for
a
reduced
abundance
of
green
herbaceous forage types (section 4.3,2), The proportion
of forbs
in the
season, but
tissue of
also
rose
in
the
dry
contributed mainly by desiccated
dead or dormant forbs that kudu and steenbok
ignored. The
is probably
surface
impala diet
this was
ability of impala to use this forage type
related to
water,
while
the dependence
steenbok
and
of
impala
on
kudu
depend
on
preformed water in their diets.
Dietary diversity
from the
late wet
and overlap
season to
among species increased
a peak
in the
late dry
hypothesis adhered
Schoener (1982,
probability
over
to
that
Smith
et
al.
(1978)
finding indicates
interspecific
intraspecific
because if
by
1986a), this
competition
competition
for
interspecific competition
food.
ai
a li
prevail
This
:
was prevalent i
most intense in the lean season, and then e
lity food
types,
specifically
found
that
fruits in
the wet
separate f
1978: but
baboon
on
marula
{Scl&roaarya
observations).
However, amon
(Appendix 8) was
ficient
for
this
dietary overlap.
convergence
to
result
in
probability of
relatively
higher
r
I
having relatively
higner preferences for certain shrub
species.
Wet season
steenbok
feeding preferences
were
strongly
condensed tannin
of
kudu,
negatively
levels in
iropala
related
to
and
leaf
their food plants (section
4,3,0.1), This relationship fell away in the dry season
when the
choice of
negative relationship
and
feeding
conforms
savanna ruminants
tannin
with
(van
level
previous
Woven,
1964;
Owen-Smith, 1985). However, I found no such
relationship to
of giraffe.
apply during either season in the case
A relationship
accessibility-related
feeding
types was reduced. A
between condensed
preference
observations on
Cooper and
woody forage
preferences
could have
factors
for
been masked by
influencing
some
of
the
giraffe
woody
plants
assayed (section 4,4.2.3). Nevertheless giraffe clearly
tolerated relatively
high levels
of
dietary
tannins
during certain periods of the dry season, when they fed
entirely on
tannini.erous
Acacia trees
foliage,
(Appendix Bl).
with proline-rich
almost
Deactivation
salivary proteins
all
of
from
tannins
(Mehansho et a J ,,
1987) has been suggested as a means by which deer avoid
the digestion-inhibiting
effects of
food plants
al,, 1987b}. It could well be
(Robbins et
tannins in
their
that the same applies for savanna browsers, and giraffe
in particular,
{op, cit.) to
as proline-rich
impart viscosity
proteins are
reported
to saliva, and giraffe
i.
saliva is particularly viaoous (section <1.4.2.2).
f.4 The influence of body size on resource use
A dominant
theme running
Investigation
is
that
through the
resource-use
results of this
dit
rences
arc
related to body size differences among species. This is
not a
new
finding.
asserted that
resources
Huxley
(1942}
coexisting species
usually
differ
in
and
Lack
using the
body
size.
(1947)
same food
Hutchinson
(19S9) concluded that for two such species the ratio of
linear dimensions
be approximately
of the
suggested, indicates
to permit
larger to the smaller should
1.3, This empirical ratio, Hutchinson
the kind
two species
of difference neceaaary
to coexist at. the same level of
the food web.
Scores of
examples of
Rule" have
now
been
Indeed, Owen-Smith
ungulates are
root of
conformity
published
with
(see
"Hutchinson's
Greene,
1987),
(1985) showed that African browsing
discretelr graded in size, with the cube
the average body sine ratio between successive
species being
this grading
and leaf Istem
very near 1.3. Owen-Smith suggested uhat
reflects the
distribution of
leaf sizes
ratios prevailing among woody plants and
forbs, However, there is now evidence that Hutchinson’s
rule is
1.3
based on
a statistical artefact. A ratio near
will result from comparing the linear dimensions of
many objects
(even some inanimate ones) in nature that
are log-normally
with standard
1987). Why
distributed, and occur in assemblages
deviations less
sympatric species
cannot be
is
the cause
and Greenough,
species
unclear,
as
in many
competition
alone
cases (reviewed by Pagel
1987). Irrespective of the way in which
are
graded
differences exist
important
than one IEadie et al.,
this size distribution should prevail among
in
was
size,
found
consequences
for
the
to
fact
have
the
resource
use
that
size
following
among
the
browser species studied:
6.4.1
Body size and dietary tolerance
My results
show that
giraffe select
new shoots, pods
and flowers (mainly from Ac.'i 'ia species) when these are
available (section
higher proportion
seasonal cycle)
than did
Pellew
to fruits
steenbok. This
(1984a)
feeders,
that
Such
understanding that
giraffe has
high
4.3.1). In fact giraffe allocated a
of feeding time (on average over the
food
and flowers of woody plants
finding conforms with that of
giraffe
findings
are
because a
rate,
it
selective
the
herbivore
low mass-specific
intake
highly
contradict
as
general
large
metabolic costs
should
feed
as
but
a
relatively
unselectively on high-fibre foods (deist, 1974; Jarman,
1974; Demment
and
Georgiadis, 1986).
van
Soest,
1986;
MoNaughton
and
However, Bell (1971) noted that the
i
optimal diet for all herbivores is that which is highly
nutritious
and
departures
from
digestible.
this
It
optimum
increasing bodysize. Indeed,
parts are
low in
notavailable
quality, both
secondary compounds
is tolerance
that
for
increases
with
when high quality plant
the giraffe diet is relatively
in
terms
of
fibre
(section 4.4.2.4:
and
plant
see also
Hall-
Martin, 1974a,b).
The
influences that
digestive system
the feeding
differences
ecology
interpreted largely
fibre contents
Demment and
in
body
sizs
{i.e. ruminant/non-ruminant)
of
large
in terms
of selected
herbivores
of
have
differences
diets (e.g.
van Soest,
1985). While
this
for grazers,
it
may
is
been
in
Janis,
suitable interpretation
and
have on
the
1976;
be
a
becoming
increasingly apparent that plant secondary chemistry is
an additional factor to be considered, particularly for
browsers (Cooper
1987a;
and Owen-Smith, 1985; Bobbins et al.,
Cooper
et
4 ,4 .2.2) , Whether
abilities of
compounds
is
indicates that
or
browsers
to
unknown,but
body
size influences
withstand
study,
the
plant
secondary
circumstantial
evidence
it might do (section 4.4.2,4) and this
requires i n v e s t i g a t ! .
body size
1988;this
al ■,
not
Either way,
the influence
of
on the feeding ecology of herbivores is more
accurately interpreted
in terms
of the
range in diet
section
quality tolerated,
than dietary
fibre content
per se
(see also Bell, 1984).
6.4.2
Body size and habitat specialisation
My findings
indicate that
with increased
increased dietary tolerance
body size
enables the larger herbivore
species to
feed in
a more
diverse range
than
smaller
species
(section
the
generality
of
general
The
size
trend
this' habitat-use / body
requires further
ungulates it
of habitats
3.3.1),
investigation, although among African
appears to
styles
of
be well supported. Among five
feeding
behaviour
among
African
antelope, Jarman (1974) recognised a tendency for small
species to remain in one vegetation type throughout the
year, and
progressively larger
progressively wider
applicable to
the trend
African ungulate
provide an
explanation (du
press) for
why population
species population)
average body
species to
range. If
size
species, then
Toit
and
a
it will
Owen-Smith,
metabolism (energy
tends to
among
feed in
is generally
in
use per
increase with increasing
these
species
(Owen-Smith,
1968). Simply stated, larger species are able to spread
more evenly
range of
through ecosystems
by feeding
in a wider
habitats, and so metabolise a larger fraction
of available
plant biomass
than smaller
species
can
The above
hypothesis has
important
implications
for
resource partitioning. If small-bodied ungulate species
specialise on
then
using different
niche
overlap
negligible.
Evidence
among
for
habitats to
these
this
in
complete ecological
separation of
browsers: steenbok,
which occur
savanna;
klipspringer,
outcrops;
thickets
and
species may
of their
bushbuck,
(Pienaar,
encroach on
feeding is
will
KNP
is
be
the
the following small
open
occur
which
1963;
the
in
which
each other
species
patches
only
occur
Smithers,
on
in
of
rocky
riverine
1983).
Larger
these habitats but the impact
distributed by their use of other
habitats too.
6.4.3
For
Body aiee and home range area
the
four
species
relationship between
(section 3.3.2).
relationship is
with
I
and
found
home
a
close
range
ares
The body mass exponent (1,38) in this
significantly higher
exponent expected
scale
studied
body mass
if home
body
mass
than
0.75,
the
is
assumed
to
range area
in
proportion
to
metabolic
requirements (HcNab, 1963). Other studies on home range
scaling
among
Bunnell, 1979;
body mass
herbivorous
Swihart et
mammals
al., 1988)
exponents significantly
(Harestad
and
have also found
greater than
0.75,
and not significantly different to that reported here.
t
My data
set is
current
not extensive
debate
on
disproportionately larger
to require
for
their
section 3.1.2).
animals
metabolic
home range
conducted in
different
modifying McNab’s
from
resolve
feel
area than
(reviewed
based on
a
variety
regions,
the
over
a
they are expected
needs
Current theories,
estimates of
home range
enough to
why
are
in
published
of
atudi. j
concerned
with
(1963) original hypothesis. That is,
area must vary as a function of the minimum
area an individual has to cover in order to feed itself
(Scnoener, 1968;
Harestad and
1981b; Lindstedt
et e.1.,
assumption is
not supported
field studies.
I
animals were
found
the distances
that
Giraffe,
example,
for
Acacia savanna
feed in
evidence
that
my
study
did
would
in which
in
order
walk
trees were
to
survive.
steadily
in full
through
leaf, to
Dichrostachys cinerea that were in
3.4,3), Hence I consider a more realistic
approach is
ground as
this
resource limitation) to cover
they
patches of
pod (section
Demuth,
propose that
by adequate evidence from
no
forced (by
Bunnell, 1979;
1986). X
to assume
an animal
it profitably
function of
benefits
will cover
as
much
can. This area will vary as a
and
costs.
Benefits
would
be
determined by the productivity and heterogeneity of the
environment,
and
costs
variables,
including
energetics
of
(section 3.4.2).
by
various
metabolic
locomotion,
size-dependent
rate,
dietary
speed
and
tolorance,
etc.
6.5
Feeding height separation
Almost all
giraffe feeding was at a higher level in the
vegetation
than
smaller than
that used
kudu the
considerable {section
the generality
of
by
Lamprey's
levels in
the
feeding
height
species, Giraffe
vertically
was
questions
hypothesis
by
feeding
(see
also
that
at
different
McNaughton
only
are quite
capable of
Kenya, giraffe
have been
feeding
to
(Leuthold and
(1963)
separates
For example
time
finding
and
For savanna browsers I suggest that
levels though, so even this
be complete.
species
ungulates tend to partition
vegetation
Oeorgiadia, 1986).
but for
feeding levels
4,3.7). This
differently-sized browsing
their resources
kudu,
overlap in
giraffe
from
other
feeding at low
separation might not always
in Tsavo East National Park,
found to
browsing
below
Leuthold, 1972).
allocate about BOX
a
suggestion
(seealso Leuthold, 1978) that
the woody
layer by
elephants
height
This gave
and
of 2
re
rise to the
reduction of
fire could
bring
giraffe into competition with smaller browsers.
Although giraffe
canopy of
have exclusive
access to
the
upper
mature trees, these trees grow from saplings
and seedlings,
herbivory on
replacement of
which are food to
other browsers, If
saplings and seedlings was exceaaive then
the mature canopy,
where
damaged by
elephants for
possibly of
Schoener,
example, would
be retarded.
long-term exploitative
1983)
between
the
Hence
the
competition {senau
smaller
browsers
and
giraffe must be considered. This type of competition is
evident in
the boreal
forests of North America. There
snowshoe hares (Lopus americanus) van impact so heavily
on
preferred
woody
alaxensis, that
food
ia severely
{A.lces alcea)
plants,
the abundance
den,, ties (Wolff,
such
as
Salix
of browse used by moose
reduced
during
peak
hare
1980, Belovsky, 1984). I consider it
unlikely that such an interaction Is of much importance
among browsers
in African
French, 1986,
do not
savannas
though
(but
see
for grazers), where the smaller browsers
reach the high densities that snowshoe hares do
in North America.
6,6
Browser - woody plant interactions
Results of
this aspect
indicate that
induces
severe
compensatory
of the
browsing
growth
study (section
on
of
Acacia
shoots,
5.1.3)
nifrescens
which
bear
foliage that is more nutritious and palatable than that
on lightly
browsed trees.
This result
conforms
with
previous findings on the nutritional quality and growth
of
woody
plant
shoots
following
pruning
by
larqe
browsing mammals (Danell et dj., 1985, Danell and HussDanell, 1985;
Pellew, 19836]
al., in press).
Teague, 1987;
Bryant et
and (b>
Rhoades (1985)
proposed exactly
grounds, postulating
this
that herbivores
on
theoretical
should be either
stealthy or opportunistic in countering plant defences,
Stealthy herbivores should minimise damage to plants so
that
defence
responses
Schultz, 1988) ,
are
not
invoked
(but
see
while opportunists should employ maes-
attack behaviour and thereby take advantage of stressed
plants. As
with many
the validity
other plant-herbivore relations,
of the
above hypothesis
awaits
further
investigation.
The
induction
of
nigrescens shoots
feedback loop
The scope
compensatory
of further
of the
conclusion, but
growth
of
Acacia
by severe browsing would result in a
browsing (section
study was
too limited
to
6.1.4.1).
reach
a
I suggest that a feedback loop of this
kind could result in the eradication of preferred woody
browse plants
where herbivores
near surface
water. Herbivory
concentrate,
such
as
by large mammals is not
always deleterious to savanna woody plants though. Some
plants, particularly
the Acacias,
disperse!
that depend
of pods
schanisms
hy ungulates
In addition
other s p e d
of their
I suggest
3
evolved
seed
(reviewed by Coe and Coe, 1987).
that A. nigrescens, and perhaps
too, might
flowers by
have
upon the consumption
benefit from the consumption
giraffe, which have the potential
to be very effective pollen vectors (section 6.2).
6.7 How does resource partitioning occur?
From the results of this study I conclude that resource
partitioning
is
ruminants in
the central KNP, This is by virtue of the
clearly
evident
among
browsing
following:
a). Habitat specialisation
among the
smaller
species
(steenbok, klipspringer, bushbuck, etc. ) results in
separation between
The tendency
diverse
some or
for larger
range
of
communities)
lessens
resources in
habitats
habitats
their
specifically adaptei
b). Syntopic species
most of these species.
species
use
a
more
vegetation
impact
on
browse
ch smaller species are
. on 6,4.2).
feed along
distinctly
foraging paths,
as defined
associated with
feeding sites
giraffe feed
to
(i.e
at higher
by
the
different
woody
plants
(section 6.2),
levels in
the
and
vegetation
than other species do (section 6.6).
c ). Syntopic
species
grass, f irbs,
differ
and
woody
in
(section i. .1).
Such dietary
separate species
completely,
overlap vn-ng them.
the
browse
proportions
in
their
differences do
but
reduce
of
diets
not
dietary
i
d). Because of
morphological variations among browsers
and plants,
foliage
accessible to
on
certain
some browsers
plants
is
more
than it is to others.
For example, giraffe (being taller) can feed in the
upper canopy
(having a
where kudu
cannot reach,
narrower muzzle)
can pluck
and impala
leaves from
between the thorns of \cao:’
.a tortilla, which are an
effective deterrent
against kudu (Cooper and Owen-
Smith, 1988; see also section 4,4.2.3)
e). Dietary tolerance
1971;
see
also
browser species
nutritional
increases with
section
may consume
quality
body size (Bell,
6.4.1),
so
the
larger
forage types of lower
than
can
be
tolerated
and
e),
electivities
by
smaller species.
f). Because of
factors d)
woody plants
tend to
for
differ, particularly between
large and small species (section 6.3,3).
The dry
season is
factors that
this period
the four
the lean
result in
species studied,
Impala and
steenbok to
partitioning
during
are those most deserving of attention. For
season occurs
Giraffe and
season in the KNP, so the
resource
by spacing
kudu
are
steenbok are
niche separation in the dry
along three
separated
by
axes (Fig 6.1).
feeding
height.
separated by the tendency for
remain on the upper catena when impala are
Figure 6.L Niche separation (in the dry season) between giraffe (G),
kudu (K), Impels (I), and steenbok (S), Positions of each species
along the three axes are relative to other species, and the distance
between positions indicates the degree of separation.
"Electivities for woody food plants.
'i
feeding mainly
(giraffe and
(impala
along the
riverlines. The
larger pair
kudu) are separated from the smaller pair
and
steenbok)
electivitiea for
by
woody plants.
preferences for
differences
in
The larger
their
pair share
certain tree species while the smaller
pair share preferences for certain shrub species.
6,8
Why does resource partitioning occur?
Considering the
degree to which the browse resource is
partitioned among
that interspecific
avoided. This
resource
browsing ruminants,
competition is
raises the
partitioning
following questions:
maintained
competition? (2)
ia resource
of
through
competition
resource partitioning
alli or
would it
it is
by
(1) is
present-day
partitioning the product
evolutionary
the product
also occur
apparent
largely or entirely
in a
of
(3)
is
competition
time?
at
randomly assembled
group of ungulate species?
Firstly, if
niche separation is maintained by present-
day competition, then niche expansion is to be expected
in the absence of potential competitors. However, among
the species
is limited
kudu cannot
studied, the potential for niche expansion
by morphology
feed any
cannot disperse
and physiology. For example,
higher than
they do, and impala
away from riverlines in the dry season
"A"
1
that if
competition
is
important
in
"petition through evolui
Ly important contributing
.d.
'
!i
'j
6.9
.
Browsers end grazers compared
The feeding
ecology of
African savanna
ungulates
is
currently understood mainly in terms of grazer-oriented
research
findings
(for
reasons
outlined
in
the
Introduction). My study is the first to include a range
of browsers
that were studied together and by the same
methods. Hence this pr- "ides an opportunity to consider
the applicability
established for
to the
browsing guild of principles
the grazing
guild, These
include the
following:
1). Diet quality varies as a function of fibre content,
and dietary
fibre content increases with body size
(Gelst, 197-1).
applies to
(a) the
This,
the
Jarman-Bell
principle,
browsers if it is adjusted to allow for
fact
function of
that
both
forage
quality
secondary
varies
chemistry
content (section
4.4.2,21, and
tolerance varies
more closely
(b)
as
and
that
a
fibre
dietary
with body size than
does average diet quality per se (Bell, 1971, 1984;
section 4.4.2.41.
2). Species move
season
down the catenary sequence in the dry
(Bell,
Sinclair,
1970;
1979).
Jarman,
Although
1972;
this
does
Jarman
apply
and
to
browsers, particularly giraffe (Hall-Martin, 1974b;
Fellow, 1984a;
section 4.3.2,21,
the
very
small
t
browsers such
as steenbok
and klipspringer do not
exhibit this pattern. These species remain in their
specific habitats
on the
upper catena
throughout
the seasonal cycle.
3), Smaller species depend on larger species to trample
and remove coarse plant matter, so as to facilitate
access
to
high
quality
Fitzgerald, 1960;
1970, 1971;
Gwynne
species
"grazing
(elephant
excluded)
that there
grazing
species
species because;
efficiency (as
by
(a) this
is
Bell,
does
not
predator
they actually
outcome of
do not
physically
the benefit of smaller
is debate
as to whether
follow larger
grazing
improves their
generally
Norton-Griffiths,1982;
smaller,
succession"
vegetation to
species. Note
benefit
(Vesey-
1968;
browsers, as the feeding actions of large
modify woody
smaller
Bell,
McNaughton, 1976; Haddock, 1979). This
principle, termed
apply to
plant parte
and
assumed);
protection
Sinclair,
displace the
they
(Sinclair
1986);
or
larger species
scramble competition
narrower-muzzled
feeding
(b)
(c)
as the
that favours
species
and
(Illius
the
nd
Gordon, 1987) ,
4). Oregariousness
may
(McNaughton, 1984).
vegetation structure
increase
foraging
efficiency
This is by the modification of
to increase
food
yield
per
bite to
the individual
"grazing
lawn"
applicable
to
in a herd (op. clt.). This
principle
browsers,
does
although
indeed
not
seem
directly.
Where browsing pressure is concentrated, food yield
per
bite
(with
nutrients) is
the
yield
being
digestible
indeed improved, but not for reasons
of altered
plant structure. Rather, severe pruning
results in
altered leaf
levels
enhanced
and
chemistry, with
condensed
nutrient
tannin
levels
depressed (section S.1.4.1).
From the
above comparisons
I conclude
that currently
accepted principles in African ungulate feeding ecology
are loosely applicable to browsers. The major exception
is that of grazing succession, and others (specifically
the
Jarman-Bell
principle
hypothesis) would
was accepted
and
the
grazing
lawn
be more applicable to browsers if it
that diet
quality varies
not only
as a
function of fibre, but of secondary chemistry as well.
6.10
The value of the guild approach, and the next step
Section
adopting
6.9
(above)
a
guild
demonstrates
approach
consumer/resource relations.
feeding ecology
a particular
an
to
advantage
of
investigating
That is, if principles of
are established for representatives of
taxonomic group (e.g. ungulates) within a
particular guild,
these principles
may be
tested
on
i
representatives
of
the
same
group
in
another
("control") guild. The comparison might then show where
modifications are
value of
required to
such principles
increase the predictive
to the
taxonomic group as a
Another advantage of the guild approach is that because
it is resource-defined, it is flexible in the taxonomic
range
over
which
consumer-resouree
consumer relations
demonstrated
by
gronivore guild
1986). The
and
consumer-
may be studied. This flexibility is
a
long-term
(Brown et
study
on
al,, 1979;
the
Brown
desert
et
a!.,
study was initially established to test for
competition between
ewanded when
rodents and
ants, and
results indicated
was
that rodents
later
compete
not only with ants, but with birds as well,
I suggest
that
the
that the
work
developed upon
groups
of
foliage for
above example
embodied
is illuminating, in
this
thecis
could
be
by expanding the guild to include other
animals
food.
that
depend
Insects
regard, particularly
herbivory does
in
in view
not only
are
upon
a
of the
remove
dicotyledonous
priority
part
in
this
fact that insect
of
the
browse
resource, but may alter the nutritional quality of that
which remains (reviewed by Schultz, 1988),
A more
immediate step
by which
the results
of
this
study
may
be
built
modelling (see
upon
is
Starfield and
to
employ
ecological
Bleloch, 1986). A number
of relationships have been identified among the feeding
patterns of
browsers, and
incorporation into
these
predictive
lend
models.
include: the
relationships between
composition,
with
below which
the
of
come into
to
examples
rainfall and
identification
such relationships
themselves
Some
diet
thresholds
effect; the
Influence of phenology (flowering, fruiting, leaf flush
etc.) among
certain plant species on diet composition;
the relationship
between rainfall
and movement acroiis
the catenary sequence; the relationship between feeding
preference
and
relationship
leaf
condensed
between
browsing
production and
between body
tannin
nutritional quality,
size and
content;
pressure
and
the
shoot
the relationships
dietary tolerance,
aa well
as
diversity of habitat use; the relationship between body
size and home range area; etc.
I
suggest
that
application of
inclusion of
system for
suitability
a
particularly
the results
the
above
the Transvaal
of
private
of my
useful
relationships
lowveld, for
holdings
indigenous browsing ruminants.
management
study would
for
in
an
be the
expert
assessing
stocking
the
with
REFERENCES
Abrams, P,A,
1980. Some
comments on
measuring
niche
overlap, Ecology 61: 44-49.
Alldredge, J.R.
and Ratti,
some statistical
J,T. 1988.
techniques for
Comparison
of
analysis
of
the
resource selection. J , ttlldl. Manage- 50: 157-165.
Allen-Rowlandson, T.S.
Organisation
of
strepsiceros Pallas
Kudu Reserve,
ALtmann, J.
1980, PAe
The
Social
Greater
and
Spatial
(Tragelaphus
Kudu
1766) in
the
Andriea
Voslco
Cape.
PhD
Thesis,
Rhodes
Eastern
1974. Observational
study
of
behaviour:
sampling methods. Behaviour 49: 227-267,
Mtmann, S.A.
1687. The impact of locomotor energetics
on mammalian
Altmann,
S.A.,
Nutrients and
foraging. J.
Post,
D.Q.,
Zoo!. (Lond,I 211: 216-
and
Klein,
D,P.
1987.
toxins of plants in Amboseli, Kenya.
Afr, J, Ecol, 25: 279-293.
Anderson,
D.J.
nonparametric
1982.
The
estimation
home
range:
technique.
A
Ecology
new
63:
s:
_
...
t
Belsky, k.3.
1987. The effects of grazing: confounding
of ecosystem,
community and
organism scales.
Am.
Nat. 129: 777-783,
Berry, P.S.
1978. Range
Luangwa Valley,
Black, C.A.
movements of
Zambia. B.
1982. Methods
Chemical and
giraffe in
the
Atr. Wildl. J. 16: 77-
of Soil
Analysis
Microbiological Properties.
Part
2:
American
Society of Agronomy Inc., Madison.
Botkin, D.B.,
Hellilo, J.M.,
ecosystem processes
are
population dynamics,
and T.D.
and Wu, L.S.Y, 1981. How
linked
to
Pages 373-387
Smith {eda. ).
Dynamics of
large
mammal
in C.W. Fowler
Large
Mammal
Populations. John Wiley and Sons, New York.
grower, J.B.
and Zar,
J,H. 197 7. Field and Laboratory
Methods for General Ecology. Wm. C. Brown, Iowa.
Brown, B.W,
and
Hollander,
Biomedical Introduction.
Brown, J.H.
1976. Chapter
H.
1977.
John Wiley
Statistics.
A
and Sons, New
13. Geographical Ecology of
Desert Rodents. Pages 315-341 in M.L, Cody and J.H.
Diamond
(eds.).
Ecology
and
Evolution
of
Communities.
Harvard
University
Press,
Massachusetts.
Brown, J.H.,
Davidson, D.W.,
An experimental
and Reichman, O.J. 1979.
study of competition between seed-
eating desert rodents and ants. Am. Zcol. 19: 1129-
Brown, J.H.,
Davidson, D.W.,
R.S.
Chapter
1986.
ecology: the
in J.
Hunger, J.C. and Inouye,
3.
Experimental
community
desert granivore system. Pages 41-61,
Diamond
and
T.J.
Case
(eds.).
Community
Ecology. Harper and Row, New York.
Brown,
J,H.
and
ecological
Maurer,
dominance,
B.A,
and
1986.
Cope's
Body
rule.
size,
jVature
(land.) 324: 248-250.
Bryant, J.P.
and
winter forage
The role
Kuropat,
P.S.
by subarctic
1980.
Selection
browsing
of
vertebrates:
of plant chemistry. Ann. Rev, ficoi. Syat.
11: 261-286.
Bryant, J.P.,
Chapin,
Carbon/nutrient
relation to
F.S.,
balance
and
of
Klein,
boreal
vertebrate herbivory.
D.R.
plants
Olkos 40:
1983.
in
357-
Bryant, J .P,, Wielawi, Q.B., Clausen, T . , and Kuropat,
P. 1985, Interactions of snowshoe hare and feltleaf
willow in Alaska. Ecology 66: 1564-1573.
Bryant, J.P.,
and Chapin,
F.S. III.
1906. Browsing -
woody plant interactions during boreal forest plant
auocession. Pages
Chapin III,
213-226 in
P.W. Flanagan,
Dyrneas (eds.).
K. Van
Cleve,
L.A. Viereck
Forest Ecosystems
F.S.
and C,T,
in the
Alaskan
Taiga. Springer-Verlag, New York.
Bryant, J.P.,
Chapin,
Clausen, T.P.
defense in
F.S,III,
Alaska paper
manipulation
Reichardt,
1987. Response
of
of
birch and
plant
P.B.
winter
and
chemical
green alder to
carbon/nutrient
balance.
Oecologia (Berl.) 72: 510-614.
Bryant, J .,
and
Danell, K , ,
Clausen,
browsing
plants.
on
In
T.
t:e
D.W.
Provenza,,F.,
In
press.
chemistry
Tallamy
Phytochemical Induction
and
Reichardt, P.,
Effects
of
of
deciduous
M.J.
by Herbivores-
Raup
mammal
woody
(eds,)
John Wiley
and Sons, New York.
Brynard, A,M.
and Pienaar, U.de V. 1960, Annual report
of the biologists. 1958/69, Koedoe 3: 1-205,
Burt, W.H. 1943. Territoriality and home range concepts
as applied to mammals. J. .Vammal. 24 : 346-352.
Byers, R.C., Steinhorst, R.K., and Krausman, P.R. 1984,
Clarification
of
a
technique
utilization-availability data.
for
J.
analysis
Wildl.
of
Manage,
48: 1050-1063.
Calder, W,A.
III. A
dimensional
trade-off between space and time:
constants
in
mammalian
ecology.
J■
Theor. Biol. 98: 393-400.
Calder,
W.A.
History,
III.
1984.
Harvard
Size,
Function
University
Press,
and
Life
Cambridge,
Massachusetts,
Carpenter, F,L.
1978. Hooks
for
mammal
pollination?
Oecologia (Berl.J 35: 123-132.
Clutton-Brock, T.H.
and population
657-676
in
Behavioural
and Albon,
S.D. 1986. Competition
regulation in social mammals. Pages
R.M.
Sibly
Ecology,
and
R.H.
Ecological
Smith
(eds.) .
Consequences
of
Adaptive Behaviour. Blackwell, Oxford.
Coates Palgrave,
K. 1981.
Struik, Cape Town.
Trees of
Southern
Africa.
Connell, J.H. 1976. Some mechanisms producing structure
in natural
communities: a
field experiments.
J.M.
Diamond
model and evidence from
Pages 460-490
(eds.).
Communities, Harvard
Ecology
in M.L. Cody and
and
Evolution
University Press,
of
Cambridge,
Massachusetts.
Connell, J.H.
1980. Diversity
competitors, or
the
ghost
and the
of
coevolution of
competition
past.
Oikos 35: 131-138.
Conybeare, A. 1976. Notes on the feeding habits of kudu
in the
Kalahari sand area of Wankle National Park,
Rhodesia, Arnoldia (Rhod.) 7: 1-7.
Cooper, S.M.
1985. factors Influencing the Utilization
of Woody Plants and forks by Ungulates. PhD thesis,
University of the Witwatersrand,
Cooper, S.M, a m
deter feeding
Jwen-Smith, N. 1986. Condensed tannins
by browsing
ruminants
in
a
South
African savanna. Oecologla (Berl.l 67: 142-46.
Cooper, S,M.
and Owen-Smith, N. 1986. Effects of plant
spinescence
in
large
mammalian
Oecologia (Berl.), 68: 446-466.
herbivores.
sed
germination
responses
Damuth, J ,
1981a. Populefcii
Damuth, J.
1987. Interspecific allometry of population
Independence of
use. Biol,
body mass
and
population
energy
Linn. Soc. 31: 193-246.
Danell, K. and Huss-Danell, K. 1986, Feeding by insects
and hares
on birches
earlier
affected
by
moose
and Bergstrom,
R.
1986.
browsing, Oikoa. 44: 75-81.
Danell, K ,,
Huss-Danell, K.
Interactions between browsing moose and two species
of birch in Sweden. Ecology 66: 1867-1678,
Demment, M,W.
and van
Digestive
Soest, P.J.
Capacity,
and
Winrock
Herbivores-
1983,
Feeding
Body
Size,
Strategies
International,
in
Morrilton,
Arkansas,
Demment, H.W.
and van
explanation for
Soest, P,J, 1985, A nutritional
body-size patterns of ruminant and
non-ruminant herbivores. Am. Nat. 126: 641-72,
Demment, H.W.
portable
and Greenwood,
computer
observations of
for
C ,B , 1987.
real-time
The use of a
recording
of
grazing behaviour in the field, J.
Range Manage, 40: 284-286,
de Vos,
V., Bengis,
R,C.,
Population control
National Park.
and
of large
Pages 213-231
Coetree,
H.J,
1913.
mammals in the Kruger
in
R.N,
Owen-Smith
du Toit, J.T. and Owen-Smith, N . (In press). Body sii
du Toit,
R.Fi 1966.
Soil loss,
hydrological changes,
ipidermal
Broekhoven, L.,
Colgi
growth
factor
Pollination Ecology. Pergatnon Press, Oxford,
Fairall, N ,
1983, Production parameters of the impala,
S. Afr. J. Anlm. Sci. 13: 176-
Aepyceros melempus-
Fairall, N.
and Kleini
water turnover:
sized African
dorc&a) and
D.R. 19B4,
a comparison
antelope,
the impala
the
Protein intake and
of two
blesbok
equivalently
{Damallscus
{Aepyceros melampus). Can.
J. Anlm. Sci. 64: (Suppl.l, 212-214,
Ferrar, A.A,
and Walker,
herbivore/habitat
National Park,
B.H. 1974,
An
relationships
analysis
in
the
of
Kyle
Rhodesia, J. Sth. Afr- Vlldl. Mgmt.
Ass. it 137-47,
Foster, J.B.
1866, The
giraffe
of
Nairobi
National
Park: home range, sex ratios, the herd and food, E.
Afr. Wildl. J. 4: 139-148.
Foster, J.B,
and Dagg, A.I. 1972. Notes on the biology
of the giraffe. B. Afr. t/lldl. J. 10: 1-16.
Freeland, W,J.
herbivofy by
and ,Jansen,
D.H. 1974.
mammals: the
Strategies
of
role of plant secondary
compounds. Am. Net. 108: 169-289,
t
Goodall, D.H.
1986. Chapter
patterning. Pages
Anderson (eds.).
3. Biotope
30-40 in
J.
Community
structure and
Kikkava
Ecology.
and
Pattern
D.J,
and
Procsss- Blackwell, Oxford.
Greene, E.
1987. Sizing
Evoi.
Gwynne, M.D,
in
up size
ratios. Trends Ecol.
79-81.
1969. The
relation
to
nutritive value of Acacia pods
Acacia
seed
distribution
by
ungulates, E. Atr. IVildl. J- 7: 176-178.
Gwynne,
M.D.
and
Bell,
R.H.V.
vegetation components
1968.
by grazing
Selection
of
ungulates in the
Serengeti National Park. Mature (bond.) 220: 390-3.
Hairston, N.G.
1981. An
experimental test of a guild:
salamander competition. -Ecology 62: 66-72.
Hall-Martin, A.J.
lowveld
1974a. Food
giraffe
as
selection by
determined
by
Transvaal
analysis
of
stomach contents. J. Sth. Afr. Sfildl. Ngznt. Ass. 4:
Hall-Martini
A.J.
utilisation
of
1974 b,
A
different
note
on
the
vegetation
giraffe. Sth. Afr. J. Sci. 70: 122-123.
seasonal
'•ypes
by
Hall-Hartin, A.J.
of the
1975. Seasonal
diet of
the Transvaal
chemical composition
luwveld giraffe. J.
Sth, Afr, Wildl. Mgmt. Ass. 5: 19-21,
Hall-Hartin, A.J,,
and
chemical composition
lowveld giraffe.
Basson,
W.D.
of the
1975.
Seasonal
diet of the Transvaal
J. Sth- Afr. Wildl. Mgnt. Ass. 5:
Hall-Hartin, A.J. 1985. Ecology of the African elephant
Loxodonta africana
Pages 56-56
in the
in Research
Board of
South Afri.h.
Board of
South
Africa
National
Pai .
Division, National
Kruger
Parks
;compilers). National Parks
Research
Report
1954/85.
National Parks Board, Skukuza, South Africa.
Hanley, T.A., Sv^linger, D.E., Hanley, K.A. and Schoen,
J.W. 1986.
Relationships between
analyses for
fecal and
rumen
deer diet assessments in southeastern
Alaska. Northwest Science 59: 10-16,
Hansen, R.M., Mugambi, M.H. and Bauni, S,M. 1985. Diets
and trophic
rankings of
ungulates of the northern
Serengeti. J . Wildl. Manage. 49: 823-829.
Harestad, A,S.
and Bunnell,
F.L, 1979. Home range and
body weight - a re-evaluation. Ecology 60: 389-402,
e,
G.M. 1982. Comparisons between
e trends: problems of methodology,
in King’s College Sociobiology Group
(eds.). Current Problems in Sociobiology. Cambridge
University Press, Cambridge.
.ten, J.C.
and Smart,
long-term exclusion
N.O.E. 1984.
of large
The
effect
of
herbivores
on
soil
stomach.
E.
Afr.
browse:
structure
Hofmann, R.R,
1973.
The
ruminant
Honogr. Biol. Vol. 2. E.. Afr. Lit. Bur. , Nairobi,
Hoppe, P.P.
1984. Strategies
herbivores. Pages
R.I. Mackie
of digestion
222-243 in
(eds.).
in African
F.M.C. Gilchrist and
Herbivore
Nutrition
in
the
Craighall, South Africa.
l.D.
1987. Native
.ustralia. Pages
1-22
and introduced
in
J.B.
herbivores In
Hacker
and
J.H.
Ternouth
(eds.).
The
Nutrition
of
Herbivores.
Academic Press, Sydney,
Huntley, B,J.
1972. A
note on the food preferences of
steenbok. J. Sth. Afr. Vildl. Mgmt. Ass. 2: 24-26.
Huntley, B.J.
1982. Southern
101-119 in
Ecology
Hurlbert,
B.J, Huntley
of
Tropical
S.H.
1971.
diversity: a
African Savannas.
and B.H.
Savannas.
The
critique and
Walker
Pages
(eds.}.
Springer-Verlag,
nonconcept
of
species
alternative parameters.
Ecology 52: 577-686.
Hurlbert, S.H.
1978. The
measurement of niche overlap
and some relatives. Ecolcgy 59: 67-77.
Hurlbert, S.H.
1984. Pseudoreplication
of ecological
and the design
field experiments. Ecol. Honogr. 64:
Hutchinson, G.E. 1959, Homage to Santa Rosalia or why
are there so many kinds of animals? Am. Nat. 93:
146-159,
Huxley,
J.
1942.
Evolution.
The
Modern
Synthesis,
Kariba, Rhodesia. Oeoologia (Berl.J 6 i
i
P.J.
1972.
Seasonal
initial populations
distribution
of
large
in the unflooded middle Zambezi
J. Appl. Bool. 9: 283-299.
P.J.
1874. The social organisation of antelope
> their
Jarman, P.J.
Feeding
ecology. Behaviour
and Sinclair,
strategy
partitioning in
A.R.E.
and
the
1979.
pattern
48: 215-
Chapter
of
6.
resource
ungulates. Pages 130-163 in A.R.E.
Sinclair and M. Norton-Griffiths (eds.). Serengeti,
Dyn&mics of
an Ecosystem.
University
of
Chicago
Press, Chicago.
Jennrich, R.I.
and Turner,
non-circular home
Jewell,
P.Ai
1966.
F.B. 1869.
range, J.
The
concept
Measurement of
Theor. Biol. 22i 227-
of
home
range
in
mammals, Symp, Zool. Soo. Land. IB: 85-109.
Johnson,
D.H.
1980.
The
availability measurements
comparison
of
for evaluating
preference, Ecology 61: 66-71,
usage
and
resource
V,
habits of gerenuk in Tsavo National Park, Kenya. E,
Leuthold, W. 1978. Ecological separation among browsing
Lewis, J.A.
and Starkey, R.L, 1968, Vegetable tannins,
Home range, time, and body size in mammal a, Ecology
Loutit, S.D.,
Louw, G.N.,
approximation of
composition of
the
black rhinoceros
Louw, G.N.
and Seely, M.K, 1987. First
food preferences and the chemical
diet
of
the
desert-dwelling
Siceros bicornis
L . Madoqua
15:
1984. Water deprivation in herbivores under
arid conditions.
and R.I.
Pages 106-128
in P.M.
Gilchrist
Mackie (eds.). Herbivore Nutrition in the
Subtropics
and
The
Tropics.
Science
Press,
Craighall, South Africa.
MacMahon, J ,A .,
K.G., and
Schimpf, L'.J. ,
Bayn, R.L.
approach to
1981.
Anderson, D.C., Smith,
An
organism-centered
some community and ecosystem concepts.
J , Theor. riol. 68: 287-307.
MacNally, R.C.
1983. On
interspecific
as'sesslng the significance of
competition
to
guild
structure.
Ecology 64: 1646-1661,
Haddock,
L.
1979.
The
"migration"
and
grazing
succession. Pages 104-129 in A.R.E. Sinclair and M,
Norton-Qriffiths (eds.).
Serengeti, Dynamics of an
Ecosystem. University of Chicago Press, Chicago,
Malechfk, J.C.
grazing and
and Balph, D,F, 1987. Diet selection by
browsing livestock.
Pages 121-132
in
salivary
chemical
and
inorganic
nutrition.
Oecologia (Serl.J 66; 478-486.
HcNaughton,
S.J.
1986. On
plants and
herbivores. Am.
Nat. 128; 765-770.
HcNaughton,
S.J.
and Georgiadis, N.J. 1986. Ecology of
African grazing
and browsing
mammals.
Ann.
Rev.
Scol. Syst. 17: 39-65.
HcNaughton,
S.J,
1987.
seasonal changes
in
J.B.
Hacker
Adaptation
of
herbivores
to
in nutrient supply. Pages 391-408
and
J.H.
Ternouth
(eds,).
TVie
Nutrition of Herbivores. Academic Press, Sydney.
Mehansho, H . ,
Butler, L.G,
and
Carlson,
D.H.
1987.
Dietary tannins and salivary proline-rich proteins:
interactions, inductions,
and defense
mechanisms.
Ann. Rev. Nutr. 7: 423-440.
Moermond, T.C,
1986. A
mechanistic
approach
to
the
structure of animal communities: Anoiis lizards and
birds, Am. Zool. 26: 23-37.
Hentii, M.T.
1986. Hypothetico-deductive and inductive
tannins: a
Monro, R.H.
critique of
Wisdom et. al. Unpublished
1980. Observations
on the feeding ecology
of impala. S. A/r. J. Zool. 15: 107-110,
Moorby, J.
and Wareing,
P.F. 1963.
Ageing
in
woody
plants. Ann, Sot. (Land.) 27: 291-309.
Hurray, M.G.
1982. Home range, dispersal, and the clan
system of the impala. Afr. J. Ecol- 20: 263-269.
Mwalyosi, R.5.B.
1987. Decline
of Acacia
tortilis in
Lake Manyara National Park, Tanzania. Afr. J. Ecol.
26: 61-53.
Neu, C.W., Byers, C,R. and Peek, J.M. 1974. A technique
for analysis
of utilisation-availability
data. J.
Wildl. Manage. 38: 641-646.
Norton-Griffiths, M,
browsing, and
1979. The
fire on
influence of
the vegetation
gracing,
dynamics of
the Serengeti. Pages 310-352 in A.R.E. Sinclair and
M. Norton-Griffiths
teds.). Serengeti. Dynamics of
an Ecosystem. University of Chicago Press, Chicago.
Novellie,
P.A.
strategies
1978.
of
Comparison
blesbok
and
of
the
springbok
foraging
in
the
Transvaal highveld.
Novellie, P.A.
S. Afr. J. WildX. Res. 8: 137-
1983. The
Feeding Ecology
Tragelaphus strepsiceros
(Pslles)
In
of The Kudu
The
Kruger
National Park. DSc thesis, University of Pretoria.
Oates, L.
G. 1973.
Food
Transvaal lowveld
preferences
mopane woodland.
of
giraffe
J.
Sth.
in
Afr.
k'ildl. Ngwt. Ass. 2: 21-31.
O'Connor, T.G.
1986. A
Concerning the
Synthesis of Field Experiments
Grass Layer
Southern Africa.
i,. Savanna
flexions of
South African National Scientific
Programmes Report No. 114.
Owen,
D.F.
and
Wiegert,
R.G.
1976.
Do
consumers
maximise plant fitness? ‘Oikos 27: 488-492.
Owen-Smith, R.N. 1976. The social ethology of the white
rhinoceros Ceratotherium
simum (Burchell 1817). Z.
Tierpsychol. 38: 337-304.
Owen-Smith,
R.N.
efficiency of
1979.
Assessing
the
foraging
a large herbivore, the kudu. S. Afr.
Factors
influencing
the
; products by large herbivores.
Huntley
(eds.). Ecology
of
Tropical
and
B.H.
Walkei
Springer-
Savannas.
Verlag, Berlin.
among
S.
Vrba
African
(ed .).
Museum Monograph
gaherbi
5.H.
1985.
Comparative
in-Smithi R.N. and Cooper, S.M. 1987a. J
preferences of
ungulates
J. ffildl. Manage. 61: 372-378.
Owen-Smith, R.N.
of woody
and Cooper,
plants to
S.M. 19876. Palatability
browsing ruminants
in a South
Pagel, M.D.
and Greenough,
J.A. 1987. Explaining size
ratios in nature. Trends Bcol. Bvol. 2: 114-115.
Pellew, R.A.
and fire
1983a. The
impacts of
elephant, giraffe
upon the Acacia tortilis woodlands of the
Serengeti, Afr. J. Ecol. 21: 41-74.
Pellew, R.A.
in the
1983b. The
Serengeti.
production of
Pellew, R.A.
browser,
giraffe and its food resource
I.
Composition,
available browse.
biomass,
and
Afr. J. Ecol. 21:
1984a. The feeding ecology of a selective
the
giraffe
(Qtratta
Camelopardalis
tippelskirchi). J- Zool ■ lLon<S.) 202: 67-81.
Pellew, R.A. 1984b. Food consumption and energy budgets
of the giraffo. J , Appl. Ecol. 21; 141-159.
Pellew, R.A, 1984c. Giraffe and okapi, Pages 634-641 in
D. MacDonald
2.
(ed.). The
Encyclopaedia of Mammals:
George Allen and Unwin, London.
Pennycuick, C.J.
the concept
1979. Energy
of "foraging
A.R.E. Sinclair
and
M.
costs of locomotion and
radius", p p ,
164-184 in
Norton-Griffiths
leds.J.
imposed
SAS Institute
Inc. 1986a.
BAS
Users
Quide:
Basies,
Version 5 Edition, SAS Institute Inc., Cary, NC.
SAS Institute
Inc. 1985b. SAS Users Guide: Statistics,
Version 5 Edition. SAS Institute Inc., Cary, NC.
Scholler, G.B.
1972. TVie
Predator-Prey
Serengeti Lion.
Relations.
University
A Study
of
of
Chicago
Press, Chicago.
Schoener, T,W, 1968, Sizes of feeding territories among
birds. Ecology 49: 123-141.
Schoener, T.W. 1970. Non-synchronous spatial overlap of
lizards in patchy habitats. Ecology 51: 408-416.
Schoener,
T.W.
1974a.
Resource-partitioning
in
ecological communities. , Science (Wash., B.C.) 186:
Schoener,
T.W.
19746.
Some
competition coefficients
methods
for reso u
of
calculating
.
utilization
spectra. Am. Nat. 108: 332-340.
Schoener, T.W,
1981. An
empirically based estimate of
home range. TVieor. Pop. Biol, 20: 281-325.
T.W. 1983. Field
Senft,
R.L.,
Coughenour,
H.B.,
Bailey,
D.W,,
Rittenhouae, L.R., Sala, O.E, and Swift, D.M. 1987,
Large
herbivore
foraging
and
ecological
hierarchies. BioScience 37: 789-799.
Shannon, C.E.
Theory of
and Weaver,
W. 1949.
Communication.
The
University
Mathematical
of
Illinois
Press, Urban*.
Simberloff, D.
1983.
testing, and
Competition
theory,
hypothesis
other community ecological buzzwords,
dm, Nat, 122: 626-636.
Simpson, C.D.
In
1972. An evaluation of seasonal movement
greater
strepsiceros
kudu
populations
Pallas
-
in
three
-
Tragelaphus
localities
in
southern Africa, Zool. Atr- 7: 197-206.
Sinclair, A.R.E.
and Norton-Griffiths, M. (eds. ) 1979.
Serengeti, Dynamics
of an Ecosystem. University of
Chicago Press, Chicago.
Sinclair, A.U.E.
Competition
and Norton-Griffiths,
or
facilitation
ungulate populations
in the
M. 1982,
regulate
Serengeti? A
hypotheses. Oecologia (fieri,; 63: 364-369,
Does
migrant
test of
Sinclair, A.R.E.
1985, Does
or predation
interspecific competition
shape the African ungulate community?
J. Anim. Ecol. 64: 899-918.
Smith, J.N.M,,
and
Grant, P.R.,
Abbott,
deeding habits
L.K.
Grant, B.R., Abbott, I.J.
1978.
Seasonal
variation
in
of Darwin's ground finches. Ecology
69: 1137-1160.
Smithers, R.H.N.
African
1983. The
Subregion.
Mammals
of
University
the
of
Southern
Pretoria,
Pretoria.
Smuts, G.L. 1982. Lion. MacMillan, Johannesburg.
Southwood,
T.ft.E.
1978.
Methods
Ecological
(2nd
Edition). Chapman and Hall, New York.
Starfield, A.H. and Bleloch, A.L. 1986, Building Models
for
Conservation
and
Wildlife
Management.
MacMillan, New York.
Strongi D.R.,
Tests
of
Szyska, L.A.,
and Simberloff,
community-wide
character
D . 1979.
displacement
against null hypotheses. Evolution 33: 897-913,
Sussman, R,W.
and Raven,
P.M.
1978.
Pollination
by
lemurs and
marsupials: an
archaic
coevolutionary
system, Science (Wash., D.C.) 200: 731-736.
Sweet,
R.J.
and
Mpbinyane,
observations on
W.
1986.
the ability
of goats
regrowth
in
post-browsin/
nigrescens/ Combr&tum
Preliminary
to
control
Acacia
savanna
apicu.latum
in
Botswana. J. Grassl. Soc. Sth. Afr, 3: 79-84.
Swift,
M.J.,
Heal,
O.K.
and
Anderson,
J.M.
1979.
Decomposition in Terrestrial Ecosystems. Blackwell,
Oxford.
Swihart, R.K.,
Slade, N.A,,
and Bergstrom, B.J. 1988.
Relating body size to the rate of home range use in
mammals, Ecology 69: 393-399.
Taylor, Ci.R.
1969. The
eland and
the oryx.
Sci. Am.
220: 88-95.
Teague, W;R, 1987 . Defoliation and Browse Production of
Acacia karroo
PhD
Africa.
Hayne in
the
thesis,
Eastern
University
Cape,
South
of
the
Witwatersrand.
Terborgh, J,
and Robinson,
utility in
S. 1986.
ecology. Pages
Guilds and their
66-90 in J . Kikkawa and
D.J. Anderson
(eds.). Community
Ecology.
Pattern
and Process. Blackwell, Melbourne.
Turner, V.
1982.
Marsupials
Australia, Pages 65-66
PowelV and
as
in
pollinators
J.A.
Armstrong,
in
J.M.
(eds,). Pollination
A.J. Richards
and
Evolution. Sydney Royal Botanic Gardens, Sydney,
Unwin, D,M.
and Martin, P. 1987.
u-vng a
van Dyne,
Recording behaviour
portable microcomputer. Behaviour 101:
87-
G.M,, Brockington, N.R,, Szocs, Z., Duek, J .
and Riblc,
C.A. 1980.
Che
.>■ 4.
Large herbivore
subsystem. Pages 269-637 in A.I. Breymeyer and G.M.
van Dyne
(eds,), Grasslands,
Systems Analysis and
Man. Cambridge University Press, Cambridge.
van
Hoven,
W.
1984,
Trees’
secret warning
system
against browsers. Custos 13: 5-16.
van
Soest,
P.J.
1982. Wutritionai
Ecology of
the
Ruminant. 0 1 B Books Inc., CorvnlHs, Oregon.
van Wyk,
P,
1984,
Field
Guide
to the
Kruger National Park, Struik, Cape Town.
Trees
of the
t
VenturCom Inc. 1984. Prelude Reference Wanuai. Printing
Version
VenturCom
1.2,
Inc.,
Cambridge,
Massachusetts.
Vesey-Fitageraid, D.F.
1960. Grazing
successicu among
East African game animals. J . Mammal 41: 161-172.
Walker, B.H.,
Ludwig, D. ,
R.M. 1981.
Moiling, C.S. and Peterman,
Stability of semi-arid grazing systems.
J . Ecol. 69: 473-498.
Walker, B.H.
and Noy-Meir,
J. 1982.
stability and
resilience
Page
in
658-690
(eds.). Ecology
B.J,
of
of
Huntley
Tropical
Aspects
savanna
and
of
the
ecosystems.
B.H.
Savannas.
Walker
Springer-
Verlag, Berlin.
Walker, B.H.
and Goodman, P.S. 1983. Some implications
of ecosystem
pp. 79-91
properties for
in R.N.
Large Mammals
wildlife
management,
Owen-Smith (ed.), Management of
in African Conservation Areas. Haum,
Pretoria.
Walker, B.H,,
reported by
Lewin, R. 1986. In ecology,
change brings stability. Science (Wash., D.C.) 234:
1071-1073.
Walker,
B.H, ,
Emails,
R.H.,
Owen-Smlth,
R.N.
and
Scholes, R.J. 1987, To cull or not to cull. Lessons
from a southern African drought. J. Appl. Ecol. 241
381-401.
Walther, F.R.
1972. Territorial
horned ungulates,
examples of
behaviour in
with special
Thomson's and
reference
certain
to
the
Grant’s gazelles. Zool,
Atr. 7: 303-307.
Western, D.
on the
1976. Water availability and its influence
structure and
dynamics of
a savanna large
mammal community. £. Atr. WLldl. J. 13: 266-88.
Westoby, M.
1974, The
analysis of
diet selection
by
large generalist herbivores. Am, Nat. 108: 290-304,
White,
G.C.,
and
Biotelemetry
Garrott,
Data
-
R.A.
A
ms,
Analysis
Primer.
of
Unpublished
manuscript.
Whiten, A.,
and
Barton,
R.A.
1988,
Demise
of
the
checksheet: using off-the-shelf miniature hand-held
computers for remote fieldwork applications, Trends
Ecol. Evol. 3: 146-148,
Whitmore, J.S,
1971. South
Afr. J. Sol. 67: 166-176,
Africa's water
budget, 5.
Wiens,
J.A.
1976.
population
responses
to
patchy
environments. Ann. Rev, Ecol.Syst. 7: 81-120.
Wiens, D., and Rourke, J.P. 1978. Rodent pollination
southern African
Wiens,
J.A,
1984.
Protea spp.
Chapter
IS.
Resource
in
276:
Nature (Lond.)
systems,
populations, and communities. Pages 397-436 in P,W,
Pricei C.N.
New
Slobodchikoff, and W.S. Gaud (eds.). A
Ecology.
Novel
Systems. John
Wier, J.S.
1971.
Theeffect
water supplies
Pages 367-385
The
Approaches
to
Interactive
Wiley anti Sons, New York.
in E.
Scientific
of
creating
additional
in a central African national park.
Duffey and
Management
of
A.S. Watt (eds.).
Anima.l
and
Plant
Communities for Conservation, Blackwell, Oxford,
Wilson, V.J.
1865. Observations
Tragelaphus
strepsiceros
control hunting
scheme in
on the
Pallas
greater
from
Northern
a
kudu
tsetse
Rhodesia.
E.
Afr, ttildl. J, 3: 27-37,
Wilson, V.J.
1970.
Tragelaphus
Data
from
strepsiceros
the
culling
Pallas
in
of
the
kudu
Kyle
National Park, Rhodesia Arnoldia (Rhod.) 4: 1-26.
Wisdom, C.S.,
1987,
Gonzalez-Coloma, A.,
Ecological
tannin
proanthocyanidins,
protein
protein precipitating
and
assays.
Rundel,
P.W.
Evaluation
binding
assays
of
and
potential, Oecologia IBerl.)
72: 395-401.
Wolff,
J .0.
1980.
during peak
Hoose-snowshoe
hare
densities.
hare
competition
Proceedings
of
the
Ranger.
The
North American Noose Conference 16: 238-254.
Wolhuter, H .
Wildlife
1948. Memories
Protection
of
Society
a
Game
of
South
Africa,
Johannesburg.
Youngi E.
1972.
The
estimating wild
value
of
waterhole
animal populations.
counts
J. Sth,
in
Afr.
Wlldl. Mgmt. Ass. 2: 22-23.
Zar,
J.H,
Edition.
1984.
Biostatistical
Prentice-Hall,
Analysis.
Englewood
Cliffs,
Second
New
Appendix AL Giraffe (G920) home range and location points. Sci.lei 1
Appendix A2. Kudu home ranges and location points. Top overlay: K905
(west), K925 (east); bottom overlay: K910 (north), K900 (south).
Scale: 1 grid square s 1 km2.
T
Appendix A3. Steenbok and impale home ranges and location points.
Top overlay! ateenbok1
, S902 (west), S907 (east).
Middle overlay: impale; 1912 (squares), 191 (circles).
Bottom overlay: impaia; 1913 (circles), 1909 (triangles).
Scale: 1 grid square a 1 km2.
t h a t follows.
Hut MM; pirtertigi fiejto} tl# illoMtus
' Suple s lii ie iKOidi, lidlcitles totil ftedlii} llee ricordei In taeti Cise.
I
J#
u
ih1
1
,tiii i'rii tu
ivs
n
m
Mjst Hof till; Fercistisa f m U $ t t a illacitloi
f6rls
JcjcuJfjrfstH!
Setirlfiji m s i
lieir«l«li?s m m
Crsswfl
m sa
tortfitee h irtm ii
lucis jtmrtU
Cr
w
e
n
i
iwl
ek
t
e
J
r
c
c
jv
rj
t
rr
K
t
onrpw
Irinii rimstrn
ISrttn men
Sclemm btmt
SiitafjH NlilMrlM
Hicii
So
rl
t1
lu
UPtiWl
K
H
(tom
Mrrffii
tiMeeu rolHMli
IntlH ilrnerw
C
i
j«
pj
rii
i
M
f
J6
il
e
s
i
U
l
l
lU
6
I
«
l
l
(
if
itp
Wt
i
K
r
iM
t
J
Ciiiuliinnili
l(«HmKsiiifemi
JifMiieif/n
Senniesiriresi
Ci
l
r
ii
i
i
ii
i
if
S
tn
f
e
r
oi
c
i
fi
UiH
f
f
UfCMii
MMiMifem
kicn lltthcptiHI
Jcitd
toelfiti*
lim it ciflrs
lias fiilu ll
Jlilzll pHtrtim
h ltiilm t tlriu m
SfiVli f l l K S U t i
I C U i l fllflllH
tiem t s n l M U
torn ejjlirl
Slf/tteM leiieii
i
mieetlfled
IijsiHifrltiM
tiiiii Mtintm
ftclH i i i t u m
""
*
3I.M ,u? M.K
M
tH
566
li.H ».# tl.M !M3 ,U |
Nc
ttetili II. lenli ilet ee«pesltlM
Flint species
3
loethiy pireintigi Win; tin illotition
JH
M
T
»pr
Ml
W
»»} Sip
0»
IW
a.n U.M I1.5S
Itiil
k«(t Urtllls
H.K
lacitiljrtms
Sttimitittjs ctmi
iecMfley vim
/ ii IjNs igereiiti
Hi/ims secejilecsfs
Ml
Hi m enriilfs
Snrfi nntlHli
0,11
Smi thmcm
Men Urtllls
tom wlttUi
Imhturfts ctfisst
tupiris toHilosi
EtorelM frtirte
tenirttifl hitirmst
Cmipm sdltptrl
O.ti «,«
Hltll Itirisli
(to
lit»roslicf;s cimt
Frt
BlMtil itotl
Foi
FnUWfW Ifljisl (tildes Fit
Siritniirolltoll
UllergU teltwto
1,1!
I
J
}
1
ilium tuforuti"'’
omo o!ss
Hi m Hlnddil
lUldintlflii
Ml
0.11
I
tniFirs
0° 0.M
:
j
llto ii ulfn
!iS
lelesntto sieeiisM
Smli toulK
in
iimupw trmcuw
Iculi sruiluiuU
(it In SiriMm
fl/tMdS M lltoi/lll
Ml
tuontii lossiilitiin
SfimiitliH ifritui
1.06
Hied illitfci
Stoll ilcrtHffsi
kitii intSottlsei
0 V'
(Matt puitrufsm
Cmsunililii
5te»lisl»!
Hilt ititt till mil KOI Kill Hill Mid 30)11 HIM Hill Mill Mill
1ftl, faltis; (rt, fwv, fV, ilw .
1 5«[1« sin le skos Is, lidituisj titil W i n tin records! in eich ei
S|U(i
AppenSii C. Kean duration of feeding events (In seconds).
Sp
MpwrituiC o a t i m s ,
ainffe
Mu
l,i.
Sipelie itrlcm
UMie stvhleiMlI
lai’thacifta! sisessi
Hem eerelfelii
Hn/ltere Mchieie
Hi/tim Mtrofkytit
W ttm m tjilm is
m rm tim li ittemis
irtoarpst tricluarptt
t i m i smUri
Pelt#em ifric m t
peylliMhvi reticulate;
Prttaperejw ifissstfelatos
Ptmctrm ratundtfolius
Mu; sstiMlt
scM li tnchtpstil'i
s c ltm iw birrti
Meerieeje tin u
SulaflM paederjeferM
5»ir»itacl^s itrlem
Strythnos spirrtse
r«4mi« Mritie
lereiMlie ierieee
termhis obontt
lim n ciffrt
l i m it m rk m
lUiphus m rm ti
Ml wedy plenM
Creeperi
n .i
*
IumU
neaniot
NIM
W««
5.t.
1
,
1
•
$.43 SM2
10,1 IW
«
'Pliste lilted 6? loicias ire ill <006? pianti,
•n li the fluebir cf feedlo} eviets racgriei in eieh ceie,
ttt
0,42 UW
8.M
4
0,86 2474
&W *
Author Du Toit Johan Truter
Name of thesis Patterns Of Resource Use Within The Browsing Ruminant Guild In The Central Kruger National Park. 1988
PUBLISHER:
University of the Witwatersrand, Johannesburg
©2013
LEGAL NOTICES:
Copyright Notice: All materials on the U n i v e r s i t y of t he W i t w a t e r s r a n d , J oha n ne s bu r g L i b r a r y website
are protected by South African copyright law and may not be distributed, transmitted, displayed, or otherwise
published in any format, without the prior written permission of the copyright owner.
Disclaimer and Terms of Use: Provided that you maintain all copyright and other notices contained therein, you
may download material (one machine readable copy and one print copy per page) for your personal and/or
educational non-commercial use only.
The University of the Witwatersrand, Johannesburg, is not responsible for any errors or omissions and excludes any
and all liability for any errors in or omissions from the information on the Library website.
Author Du Toit Johan Truter
Name of thesis Patterns Of Resource Use Within The Browsing Ruminant Guild In The Central Kruger National Park. 1988
PUBLISHER:
University of the Witwatersrand, Johannesburg
©2013
LEGAL NOTICES:
Copyright Notice: All materials on the U n i v e r s i t y o f t h e W i t w a t e r s r a n d , J o h a n n e s b u r g L i b r a r y website
are protected by South African copyright law and may not be distributed, transmitted, displayed, or otherwise
published in any format, without the prior written permission of the copyright owner.
Disclaimer and Terms of Use: Provided that you maintain all copyright and other notices contained therein, you
may download material (one machine readable copy and one print copy per page) for your personal and/or
educational non-commercial use only.
The University of the Witwatersrand, Johannesburg, is not responsible for any errors or omissions and excludes any
and all liability for any errors in or omissions from the information on the Library website.