CONSERVATION
Lions - by their whiskers shall ye
know them (and what they eat)
FELIX PATTON
is a rhino ecologist,
who writes and
broadcasts about
the species from
Africa and Europe.
He has an MSc
in Conservation
Biology and a PhD based on research
into individual rhino identification
and social behaviour. He is a frequent
contributor to SWARA.
A
game reserve surrounded
by cattle and communities
is certainly not the place to
have lions that can move
in and out at will. When an area of
Kenya’s Solio Ranch was set aside for
wildlife, the surrounding fence was
made especially predator proof so no
lions, leopards and cheetahs could get
out – or in.
Since lions can live for over 10 years,
even the smallest population was
bound to grow. At the same time, all
the other wildlife - from warthogs to
rhinos - grew. By moving individuals to
other reserves, Solio’s internationally
famous and critically endangered Black
rhino population had been reduced to
a manageable level by 2008, but the
question remained as to how many lions
were there.
This was important as, apart from
humans, lions are the other main killer
of rhinos, attacking small calves under
about four months of age and any old
or infirmed adult. What method could
be employed to identify each individual
lion so as to only count them once?
Faced with this very problem when
working in Nairobi National Park, lion
researcher Judith Rudnai found that
every lion had a largely unique pattern
of whisker spots and so developed a
method of capturing the differences.
Rudnai’s system was, (and is),
employed at Solio by building a
40 SWARA APRIL - JUNE 2013
Compare the position of any spots in row A with the spots in row B for both the
left and right profiles to determine the identity of an individual lion.
database of photographs of both the left
and right profiles of any lion found and
determining their unique spot pattern
(see illustration). By the end of 2008
the lion population of Solio had been
recorded at 14 with seven males and
seven females.
For an area of only 69 sq km, this
was a high number and the concern
was what were these lions eating? An
adult lion is said to eat a daily average
of between 5-7kg of meat, albeit gorging
themselves one day and going with little
the next. This means that a single lion
may eat over 2 tonnes of meat in a year,
which is equivalent to more than 10
adult zebras.
Solio rangers monitoring the rhinos
also report sightings of lions and any
carcasses they come across, determining
whether lions killed the animal or died
of other causes. Recent game counts
showed the reserve had around 1000
buffalo, 700 impala, 600 zebra, 400
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CONSERVATION
Zebra with ripped skin after a lion attack.
warthog, 250 waterbuck and oryx and
a little under 100 giraffe and eland. The
lions had a full menu to choose from.
Lions are not stupid. They are
well aware that larger game may
present greater danger in a fight than
smaller game, while smaller game do
not provide such a satisfying meal,
especially where a pride with cubs need
feeding.
It is possible to create a risk/reward
assessment of the different prey a lion
would choose and this is shown in the
table below.
Smaller prey such as warthog and
impala present no threat to the lion
but offer little meat. Giraffe, buffalo
and oryx give more of a meal but can
cause particularly bad injuries to lions –
giraffe from a vicious kick; buffalo from
their horns and by males throwing the
lion into the air using their strong neck
muscles; oryx from piercing injuries
due to the sharp horns. Zebra can cause
Table: Body mass (kg) of main prey and their potential threat to cause injury (after Hayward
and Kerley, 2005).
Species
Body mass
Threat index
Giraffe
550
2
African buffalo
432
2
Eland
345
1
Waterbuck
188
0.5
Zebra
175
1
Oryx
158
2
Wildebeest
135
0
Warthog
45
0
Impala
30
0
Springbok
26
0
Thomson’s
15
0
Notes:
Body mass is shown as 75% of mean adult female weight to account for sub-adults and calves; threat index: 0 = no threat, 1 =
minor threat or active defence, 2 = severe threat, cause of known death to lions
Species in italics not present in Solio Game Reserve
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This zebra did not get away and was
food for a group of ten lions taking it
in turns to eat their fill.
kicking injuries and can often be seen
with bad scratch marks or wounds on
their rump where a lion has jumped on
it but has been kicked away.
Statisticians have a way of analysing
everything. By using Jacob’s Electivity
Index, statisticians can describe
whether an animal favours one
particular food source over another
when related to the amount of that food
source available. For the Solio lions,
the Index showed that zebra was the
species most preferred while the more
abundant buffalo and impala were less
desired.
This preference rating is closely
related to the injury threat. Buffalo are
avoided especially as the herd will offer
individuals protection (see the amazing
YouTube video “battle at Kruger”).
Zebra are preferred as they offer only a
minor threat. Impala are found along
the river in more open ground where
the lions have less cover in which to
stalk their prey and the impala can
easily detect them and run off.
There is a problem with the analysis
as it is not possible to account for the
fact that the kills found by the rangers
favoured the larger animals as there
is little left when a lion polishes off
a warthog or even a rhino calf. More
recent game counts showed a serious
reduction in the number of warthogs
from 400 down to less than 100. Lions
SWARA APRIL - JUNE 2013 41
CONSERVATION
All that remained of the six
month old calf 48 hours after
lions had eaten it.
Lion snacking on a warthog.
Female and six month old
calf killed by poachers.
An adult giraffe can last for more than one meal for the lions.
42 SWARA APRIL - JUNE 2013
are lazy killers and warthogs are easy
meat. The lions lie in wait on top of a
warthog den and grab any unsuspecting
warthog that shows its face. If the
warthog gets away, the long legged
lion can easily catch the short legged
warthog. When hungry and having
failed to catch a large animal, the lions
turn their attention to warthogs to ‘tide
them over’. This could also be called a
snack between meals.
The laziness of lions is well illustrated
by the fate of a poached rhino female
and calf. Two days after being shot, the
remains of the 200 kg, six-month-old
calf comprised of the bottom of one leg,
half the skull and a few bones scattered
around. The female was largely
untouched with only the udder, lips and
ears having been eaten. But the lions
had not finished and were waiting in the
bushes to return to their meal.
Another lion casualty is giraffe.
Despite their large size and high threat
of hurting an attacking lion, an adult
giraffe offers a lion a huge meal so the
reward is worth the risk. Offering 550
kilos of meat at a daily requirement of
6kg, one giraffe is worth 91 days of lion
food, sufficient to feed a large pride over
a couple of days before the meat goes off
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CONSERVATION
This greedy lion has tried to hide its zebra
kill away from other interested parties.
When lions killed two rangers in Nakuru
National Park some 10 years ago, only
their heads were left complete with
their frightened expressions.
when the scavengers like hyenas, jackals
and vultures take over.
Giraffe numbers at Solio dropped
from 96 to 80 over a 5 year period.
Apart from the lions attacking the
adults, they also killed four out of every
five juveniles meaning the replacement
rate did not match the death rate. Only
three out of 16 giraffe calves born in
2011 and 2012 had survived through to
2013.
Today Solio has a confirmed lion
population of 31 with seven females
forecast to give birth this year which
could mean as many as 20 more lions
by the year end. Despite this sometimes
offering a great tourist experience,
and apart from the danger this means
for the ranger force walking daily
in the reserve, this number will put
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great pressure on the preferred prey
species. If on average the 31 lions ate
6kg of meat a day throughout the year
and they were only to eat zebra (their
preferred species) then it would take
388 individuals to satisfy them.
While the growing number of lions
may drastically reduce the larger
wildlife population of Solio, it is the
threat to human life that is the greatest
concern. When lions killed two rangers
in Nakuru National Park some 10 years
ago, only their heads were left complete
with their frightened expressions.
Monitoring and security rangers
patrolling the Solio bush have already
had near misses, too close for comfort,
so compromising the efficiency of their
operation. Perversely, those most at
risk are intruders walking in the bush
Innocent looks but a savage nature.
at night – the current occupation of
a number of poachers. They run the
increasing risk of being savaged by
the lions which some would regard
as appropriate justice for killers of
innocent rhinos.
Locking in the lions at Solio and the
problems that have resulted, act as an
example of the future to come to other
fully enclosed, lion-inhabited, wildlife
areas. A long term solution is required
and that is in the hands of the guardians
of all Kenya’s wildlife, the Kenya
Wildlife Service.
SWARA APRIL - JUNE 2013 43