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Expedition report: A game of cats & elephants: safeguarding big cats, elephants and other species of the African savannah, Namibia (August - November 2014)

Authors:
  • Biosphere Expeditions

Abstract and Figures

Abstract This research project started in 2012 and was based on Okambara Elephant Lodge, a game farm located 85 km south of Windhoek’s international airport, in the Khomas region of central Namibia. Okambara is game-fenced and comprises an area of 150 km2. This report covers the survey work conducted during the period of August–November 2014. The key study species was the African leopard (Panthera pardus). Leopards are protected animals and listed as Near Threatened by the IUCN (International Union for Conservation of Nature). The conservation of leopards outside of protected areas in Namibia is not assured. Their “problem predator” image and high trophy value, together with habitat loss, habitat fragmentation and local outbreaks of wildlife diseases, are the main threats. These threats and the lack of scientific data on this species living on commercial farmland demonstrate the need for research. This study focussed on the spatial ecology and prey preferences of leopards on Namibian farmland. Invasive as well as non-invasive methods were used; invasive methods included trapping and collaring of leopards, whilst non-invasive methods included camera traps, track counts, search for prey remains and faeces collection. Data collected on Okambara showed differences in the ecology of leopards living on farmland and in protected areas. Home range sizes on farmland were bigger than those of leopards living in protected areas, most likely due to habitat preferences, variation in prey availability and lower predator densities compared to protected areas. The camera trap surveys on Okambara yielded a density of 1.8 individuals per 100 km2, a lower density compared to protected areas, thereby confirming the assumption that home range size is related to density. The camera trap surveys, as well as the monitoring of carnivore tracks and scats, also revealed the existence of additional carnivores and related interspecific behaviour showing that predators seem to avoid each other, thereby reducing direct competition and conflict. Despite and indeed perhaps because of this, different strands of evidence show that the habitat on Okambara is suitable for the survival and reproduction of different predator species. Zusammenfassung Im Jahr 2012 startete dieses Forschungsprojekt auf der Okambara Elephant Lodge, einer Wildtierfarm etwa 85 km südlich von Windhoeks internationalem Flughafen, in der Khomas Hochland Region in Zentral-Namibia. Okambara ist von einem Wildtierzaun umgeben und deckt ein Gebiet von 150 km² ab. Dieser Bericht befasst sich mit Untersuchungen, die dort im Zeitraum August-November 2014 durchgeführt wurden. Im Fokus der Studie stand der Leopard (Panthera pardus). Der Leopard ist eine geschützte Art und als "potenziell gefährdet" von der IUCN (International Union for Conservation of Nature) eingestuft. Jedoch kommt ein Großteil der namibischen Leopardenpopulation auf kommerziell genutztem Farmland und somit außerhalb geschützter Gebiete vor. Dadurch ist die Erhaltung dieser Art in Namibia nicht gesichert. Ihr Status als "Problem-Beutegreifer", ein hoher Trophäenwert, fortschreitender Verlust von Lebensraum und Wildtierkrankheiten sind ihre stärksten Bedrohungen. Diese Bedrohungen sowie der Mangel an wissenschaftlichen Daten machen es sinnvoll und notwendig, diese Spezies im Lebensraum Farmland besser zu erforschen. In dieser Studie standen die räumliche Ökologie von Leoparden auf nambianischen Farmland sowie deren Beutepräferenzen im Mittelpunkt. Sowohl invasive als auch non-invasive Methoden wurden angewandt; invasive Methoden beinhalteten den Fang und die Besenderung von Leoparden, während non-invasive Methoden die Nutzung von Kamerafallen und die Suche nach Kot, Spuren und Überresten von Beutetieren umfassten. Die auf Okambara aufgenommenen Daten zeigten, dass sich die räumliche Ökologie von Leoparden auf namibianischen Farmland von der in geschützten Gebieten vorkommenden Leoparden unterscheidet. Streifgebiete waren größer als in Schutzgebieten und dies ist vermutlich auf Habitatpräferenzen, variierende Beutetierdichte, sowie geringere Beutegreiferdichte im Vergleich zu geschützten Gebieten zurückzuführen. Der Kamerafallenstudie zufolge weist Okambara eine Leopardendichte von 1,8 Tieren pro 100 km2 auf. Die Leopardendichte auf Farmland ist somit geringer als in geschützten Gebieten und unterstützt die Vermutung eines Zusammenhangs von Streifgebietsgrößen mit vorkommender Dichte. Weiterhin zeigte der Einsatz von Kamerafallen, sowie die Aufnahme von Karnivorspuren und -kot das Vorkommen weiterer Beutegreifer auf Okambara, sowie damit verbundenes interspefizisches Verhalten, da sich die verschiedenen Arten in Raum und Zeit zu meiden scheinen, um Konflikte zu vermeiden. Damit ist Okambara ein geeignetes Habitat für den Fortpflanzung und Bestand verschiedener Beutegreifer.
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EXPEDITION REPORT
Expedition dates: 3 August
7
November
2014
Report published:
September
201
5
A game of cats & elephants: safeguarding big cats, elephants
1
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
organisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nation
s Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International Union for the Conservation of Nature
EXPEDITION REPORT
A game of cats & elephants: safeguarding big cats, elephants
and other species of the African savannah, Namibia
Expedition dates:
3
August
7
November
201
4
Report published:
September 2015
Author
s
:
Vera
Menges
Biosphere Expedition
s
Matthias Hammer (editor)
Biosphere Expeditions
2
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Abstract
This
research project started in 2012 and was based on Okambara Elephant Lodge, a game farm
located 85 km south of Windhoek’s international airport,
in the
Khomas
re
gion of central Namibia
.
Okambara is game
-
fenced and
comprises
an area of 150
km
2
.
This
report covers the survey w
ork
conducted during the period
of
August
November 2014. The key study species was
the
African
leopard
(
Panthera pardus
)
.
Leopards are p
rotect
ed animals and listed as
N
ear
T
hreatened
by the IUCN (International
Union for Conservation of Nature).
T
he conservation of leopards outside of protected areas in Namibia
is not assured. Their “problem predator” image
and
high trophy value,
together with
ha
bitat loss, habitat
fragmentation and local outbreaks of wildlife diseases
,
are the main threats. These threats and the lack
of scientific data on this species living on commercial farmland
demonstrate
the need for research.
This study focussed on the spa
tial ecology and prey preferences of leopards on Namibian farmland.
Invasive
as well as
non
-
invasive
methods were used;
invasive
methods included trapping and collaring
of leopards, whilst
non
-
invasive
methods included camera traps,
track
counts
, search fo
r prey remains
and faeces collection.
Data collected
on Okambara
show
ed
differences in the ecology of leopards living on farmland
and in protected
areas. Home range sizes
on farmland
were bigger
than those of
leop
ards living in
protected areas,
most likely
due to habitat preferences
, variation in prey availability
and lower predator
densities compared to protected areas.
The camera trap surveys
on Okambara
yielded a density of 1.8
individuals per
100
km
2
,
a lower
density
compared
to
protected areas
, thereby
confirming
the assumption that home range size is
related to density.
The camera trap surveys
,
as well as the monitoring of carnivore tracks and scats
,
also revealed the existence of additional carnivores and related interspecific behaviour showing that
p
redators
seem to
avoid each other,
there
by reducing
direct competition and conflict.
Despite and
indeed perhaps because of this, d
ifferent
strands of
evidence
show
that the habitat on Okambara is
suitable for
the
survival and
reproduction of different pred
ator species.
Z
usammenfassung
Im Jahr 2012
startete
dieses
Forschungsprojekt
auf
der Okambara Elephant Lodge
,
einer Wildtierfarm etwa
85 km südlich von
Windhoek
s internationalem Flughafen
,
in der
Khomas
Hochland
Region
in
Zentral
-
Namibia
.
Okambara ist vo
n einem Wildtierzaun umgeben und deckt ein Gebiet von 150 km² ab.
Dieser
Bericht befasst sich
mit Untersuchungen, die dort im
Zeitraum
August
-
November 201
4
durchgeführt
wurden
.
Im
Foku
s der Studie stand
der
Leopard (
Panthera pardus
)
.
Der Leopard ist eine
geschützte Art und als "potenziell gefährdet" von der IUCN (International Union
for Conserv
ation of Nature) eingestuft. Jedoch kommt ein
Großteil der namibischen Leopardenpopulation auf
kommerziell genutztem Farmland
und
somit
außerhalb geschützter Gebiete
vor
. D
adurch ist die Erhaltung
dieser Art in Namibia nicht gesichert. Ihr
Status als
"Problem
-
Beutegreifer
", ein
hoher Trophäenwert,
fortschreitender
Verlust von Lebensraum
und
Wildtierkrankheiten sind
ihre
stärksten Bedrohungen. Diese
Bedrohungen
sowie
d
er Mangel an wissenschaftlichen Daten
machen es sinnvoll und notwendig, diese
Spezies im Lebensraum Farmland besser zu erforschen.
In dieser Studie standen die räumliche Ökologie von Leoparden auf nambianischen Farmland sowie
der
en
Beutepräferenzen im Mit
telpunkt.
Sowohl
invasive
als auch
non
-
invasive
Methoden wurden
angewandt;
invasive
Methoden beinhalteten den Fang und die Besenderung von Leoparden, während
non
-
invasive
Methoden die Nutzung von Kamerafallen und die Suche nach Kot, Spuren und Überresten v
on
Beutetieren umfassten.
Die auf Oka
mbara aufgenommenen Daten zeigten, dass sich die räumliche Ökologie von Leoparden
auf namibianischen Farmland von der in geschützten Gebieten vorkommenden Leoparden unterscheidet.
Streifgebiete waren größer als in Schut
zgebieten und
dies
ist vermutlich auf Habitatpräferenz
en, variierende
Beutetierdichte,
s
owie geringere
Beutegreifer
dichte
im Vergleich zu geschützten Gebieten zurückzuführen.
Der
Kamerafallenstudie
zufolge weist Okambara
eine
Leopardendichte von 1,8
Tieren
pro
100
km
2
auf
.
Die Leopardendichte auf Farmland ist somit geringer als in geschützten Gebieten und unterstützt die
Vermutung eines Zusammenhangs von Streifgebietsgrößen mit
vorkommender Dichte. Weiterhin zeigte der
Einsatz von Kamerafallen
,
sowie die Au
fnahme von Karnivorspuren und
-
kot
das Vorkommen weiterer
Beutegreifer
auf Okambara
,
sowie
damit verbundenes
interspefizisches Verhalten, da sich die
verschiedenen Arten in Raum und Zeit zu meiden scheinen, um Konflikte zu vermeiden
. Damit ist
Okambara
ein
geeignetes Habitat für d
en Fortpflanzung und Bestand
verschiedener Beutegreifer.
3
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Contents
Abstract
/
Zusammenfassung
2
Contents
3
1. Expedition r
eview
4
1.1. Back
groun
d
4
1.2. Research a
rea
5
1.3. Dates
6
1.4. Local conditions & s
upport
6
1.5.
Expedition
s
cientist
s
7
1.6. Expedition l
eader
7
1.7. Expedition
t
eam
8
1.8
. Expedition b
udget
9
1.9. Ack
nowledgements
10
1.1
0
. Further i
nfo
rmation & e
nquiries
10
2.
African leopard ecology on
two
Namibian game farm
s
11
2.1. Introdu
ction
and background
1
1
2.2.
Study site and training of expedition participants
14
2.3.
Study
animal
1
4
2.4.
Methods
16
2.5.
Results
2
3
2.6
. Discussion and conclusion
s
33
2.
7
.
Literature
cited
42
Appendix I: Studies reporting mean home
range sizes and densities
49
Appendix II: Expedition diaries
& reports
50
4
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Please note: Each expedition report is written as a stand
-
alone document that can be read
without having to refer back to previous reports. As such, much of this section, whi
ch
remains valid and relevant, is a repetition from previous reports, copied here to provide the
reader with an uninterrupted flow of argument and rationale.
1.
Expedition
r
eview
Matthias Hammer
Biosphere Expedition
s
1.1. Background
Biosphere Expeditio
ns runs wildlife conservation research expeditions to all corners of the
Earth. Our projects are not tours, photographic safaris or excursions, but genuine research
expeditions placing ordinary people with no research experience alongside scientists who
ar
e at the forefront of conservation work. Our expeditions are open to all and there are no
special skills (scientific or otherwise) required to join. Our expedition team members are
people from all walks of life, of all ages, looking for an adventure with a
conscience and a
sense of purpose. More information about Biosphere Expeditions and its research
expeditions can be found at
www.biosphere
-
expeditions.org
.
This expedition report deals with an expedition
to Namibia that ran from
3
August to
7
November
2014
. The expedition was part of a long
-
term research project and assisted the
local scientist in ascertaining the status of the African leopard (
Panthera pardus
) living in
parts of mountainous game farmland
in the Khomas region of Namibia. The expedition
s
emphases were on capture activities, GPS
-
tracking, searching for leopard
signs such as
counting tracks and collecting scats, identifying individuals with the help of camera trap
surveys, and on recording p
rey animals by hide
-
based observationsat water points and on
game study drives. Additionally, a herd of
African
elephants
(
Loxodonta africana
)
was
observed daily to obtain
information
about their feeding and social behaviour
within the
confines of the fen
ced farm area study site
.
Namibia is one of a few African countries that support six species of large carnivores.
Lions, spotted hyaenas and wild dogs are mainly restricted to protected areas, but
cheetahs, leopards and brown hyaenas still occur on areas
with intensive livestock and/or
game farming. The leopard is currently not listed as an IUCN endangered species in
Namibia. However, we believe that high trophy take
-
off together with “problem predator”
reduction
,
combined with habitat loss and fragmentati
on
,
may put the local leopard
population under threat. There is thus an urgent need to gain a better scientific insight into
both leopard demographics
and
ecology outside protected areas in Namibia.
A good knowledge of leopard ecology on Namibian game far
mland will help to conserve
and protect the predator.
In 2011, the Ministry of Environment and Tourism conducted a
leopard population density estimate (national estimate: 14,154 leopards)
throughout
Namibia
on which the hunting quota for leopards was based
(250 individuals per annum)
(Stein & Aschenborn 2012)
.
However, the
removal through human
-
wildlife
conflict is poorly
monitored
and currently no reliable numbers are accessible.
5
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
1.2. Research area
At 825,418 km
2
Namibia is the world's
34th
largest coun
try
(
F
igure 1.2a)
. However, after
Mongolia,
it
is the
second
least densely populated country in the world (2.5 inhabitants per
km
2
). About 40% of the total area in Namibia is used for commercial livestock farming,
while
communal areas comprise another 40%
and
national parks and restricted areas
mak
e
up the remaining 20%
(
Berry 1990
)
. It is estimated that commercial farmland hosts
about 80% of the commercially useable larger game species (
Brown 1992
) and also
represents most important habitat types.
Fl
ag and location of Namibia and study site.
An overview of Biosphere Expeditions’ research sites,
assembly points, base camp and office locations is at
Google Maps
.
Figure 1.2a.
Map and flag of
Namibia and
location of
study site
.
The study area was centred on Okambara
G
ame Reserve in the Khomas region very
close to the Omaheke regio
n in the east
(
F
igure 1.2b)
. The Khomas region spans 36,804
km²
(
F
igure 1.2b
;
Mendelsohn 2009
)
and, due to the inclusion of Windhoek, Namibia’s
capital, has the highest human population of any region in Namibia.
Figure 1.2b
.
Regional government areas a
nd study site
(red dot)
in Namibia
.
6
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
1.3. Dates
The expedition ran
from August to November 2014
, split into seven two
-
week groups:
3
-
15 August | 17
-
29 August || 7
-
19 September | 21 September
-
3 October || 12
-
24
October | 26 October
-
7 November
2014.
All groups
were composed of a team of international research assistants, guides, support
personnel and an expedition leader (see below for team details).
1.4. Local conditions & s
upport
Expedition base
The expedition team was based at
the Okambar
a Bush Camp
on the Okambara
Game
Reserve
, about 85
km southeast
of
Windhoek’s
international Hosea Kutako
airport
,
in the
Khomas region
. The
camp (
S
22.69227
,
E
18.21029
) was situated
in the southern part
of
the
Reserve
.
Team members stayed in
chalets
equi
pped with beds, mosquito n
ets,
basic f
urniture
and
en
-
suit
e
bathrooms. Breakfast and all meals were prepared by the expedition cooks, who
could cater for vegetarians and
some other special diets. Chalets
had 220V mains
electricity from European style socke
ts.
There was also a communal building called
lapa
with a dining room, rest areas with sofas, and a fireplace with a view of a waterhole.
Weather
The climate is
semi
-
arid savannah
type
with three distinct seasons
. The
hot, dry season
runs
from September
to December when t
emperatures
can reach
40ºC
or more
during the
day and
plummet
at night
,
sometimes
to levels
below zero
. Second is a hot, wet season
f
rom January to April and third
is a cold, dry season from May to August with warm days
,
which are contras
ted by very cold nights, when temperatures often drop to below freezing.
The expedition
started at the end
of winter in
August
2014
. Annual rainfall
was
highly
variable
,
but in general rainfall in 2014
was
higher
compared to
the previous year
.
Average
dail
y temperatures duri
ng the expedition ranged from 18 to 38.3
º
C
.
Field communications
There wa
s good mobile coverage around the camp but no
coverage
in
the mountains.
Regular expedition diary updates were uploaded to
the
Biosphere Expeditions blog
,
Facebook
and
Google+
for friends and family to access.
Transport & veh
icles
Team members made their own way to the Windhoek assembly point. From there onwards
and back to the assembly point all transport and vehicles were provided for the expedition
team, for expedition support and for emergency evacuations.
7
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Cars used dur
ing the expedition were Toyota Landcruisers, provided by Christian Schmitt,
the owner of Okambara
G
ame
R
eserve.
Team members wishing to drive the
cars
had to
be older than 21, have a full clean driving licen
c
e and a new style EU or equivalent credit
-
card s
ized driving licen
c
e document. Off
-
road driving and safety training was part of the
expedition.
Medical support and insurance
The expedition l
eader was a trained first aider
and the expedition carried a comprehensive
medical kit. Namibia’s healthcare sys
tem is of an excellent standard and the nearest
doctor and hospital were
located
in Windhoek. All team members were required to carry
adequate travel insurance covering emergency medic
al evacuation and repatriation
.
E
mergency procedures were in place, but
did not have to be invoked
.
There were
some
minor medical issues such as a hurt thumb and minor dehydration
, but
no serious medical
incidents during the
expedition.
1.5.
Expedition
s
cientist
Vera Menges, born and educated in Germany, joined Biosphere Exp
editions
in 2013
. After
spending a couple of years abroad (UK & New Zealand), she graduated from the
Westphalian Wilhelms
-
University
Mue
nster in Germany with a Bachelor’s Degree in
gree in
Conservation and
Management of Protected Areas.
The latter was based on research
of
brown bears in Sweden in collaboration with the Scandinavian Brown Bear Research
Project. Since then,
she has worked for this
bear project as well as for a lynx/roe
deer
research project in the Bavarian Forest National Park, Germany
.
Now s
he is putting her
skills and passion for wildlife research and conservation towards pursuing a PhD
on
leopard ecology within the spatial ecology working group
of the Leibniz Institu
te for Zoo
and Wildlife Research in Berlin
,
as well as mitigating
the local
human
wildlife conflict by
working
o
n
the big cat project in Namibia
.
1.6. Expedition l
eader
Alisa Clickenger was born in the United States and educated at Bennington College in
Vermont. After many successful years in the corporate world, she fell in love with the path
less travelled. She now lives a life of travel and adventure, and writes about it for several
magazines. An experienced overlander on two and four wheels, Alisa
has
a
love of nature
and foreign cultures
which in 2009
brought her on a seven
-
month solo journey through
Central and South America seeking wildlife and wild places. An experienced tour guide in
the adventure travel field, at Biosphere Expeditions Alisa reali
ses a dream
that of
combining her love of people with her love of wildlife and conservation.
8
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
1.7. Expedition t
eam
The expedition team was recruited by Biosphere Expeditions and consisted of a mixture of
all ages, nationalities and backgrounds. They we
re (
in alphabetical order and
with
countries of residence):
3
-
15 August 2014
Sebastian Deiber (Austria), Simona Duranti (Qatar), Paula Malesa (USA), Polly Marti
(USA), Eva Schoenmakers (Austria), Heinrich Staudigl (Germany), Eric Stockeyr
(Belgium), C
hristine Tschynylo (Belgium), Marco Zanferrari (Qatar).
17
-
29 August 2014
Valerie Boquet (USA), Leung Siu Han (China), Lynne Ogilivie (Canada), Lesley Oliver
(Australia), John Rawnsley (UK), Glenn Woodford (Australia).
7
-
19 September 2014
Diane Bat
eman (UK), Barbara Buchter (Germany), Monika Monn (Switzerland), Rebekka
Thalmann (Switzerland).
21 September
-
3 October 2014
Edward Durell (USA), Volker Hegemann (Germany), Jeff Holten (Canada), Sonja Krezmer
(Germany), Keryn Lewis (Australia),
Nerys
Lewis (Australia), Sue McVerry (UK), Jan
Moore (Canada), James Smith (USA), Rebekka Thalmann (Switzerland), Renate Winderl
(Germany).
12
-
24 October 2014
Helen Bartholomew (UK), Emma Charles (UK), John Cotton (UK), Paul Gent (UAE),
Martina Gruben (Germa
ny), Bruce Hambour (Australia), Louize Hermitage
-
Holt (UK),
Vibeke Jensen (Denmark), Ashley O'Brien (Australia), Mara Schiff (USA), Mark Schiff
(USA), Diane Williamson (UK).
26 October
-
7 November 2014
Sabine Brandstetter (Austria), Markus Cudaj (German
y), Astrid Eglitis (USA), Sandra
Kraetschmer (Germany), Stuart McDonald (UK), Heidemarie Moser
-
Sturm (Austria), Karen
Smith (UK), Christiane Stalschus (Germany).
Also:
Guides Jesaja (s
lot 1 and 2), Legius (Slot 1 to 6), Willia
m (Slot 3), Paul (Slot 5 and
6).
9
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
1.8. Expedition
b
udget
Each team member paid towards expedit
ion costs a contribution of £
1,750
per two
-
week
slot. The contribution covered accommodation and meals, supervision and induction, all
maps and special non
-
personal equipment,
and
all tran
sport from and to the team
assembly point. It did not cover excess luggage charges, travel insurance, personal
expenses
such as
telephone bills, souvenirs, etc.,
or
visa and other travel expenses to and
from the assembly point (e.g. international flights).
Details on how these contributions were
spent are given below.
Income
£
Expedition contributions
102,701
Expenditure
Staff
includes local & international salaries, travel and expenses
, living expenses
16,234
Research
includes
equipment, anim
al capture and other research expenses
15,370
Transport
i
ncludes
bus transfers,
fuel, car tax & maintenance
16,721
Base
includes board, lodging and other base camp services
29,153
Administration
includes office costs
,
visa & professional fees and miscel
laneous costs
222
Team recruitment
Namibia
as estimated % of PR costs for Biosphere Expeditions
6,525
Income
Expenditure
18,476
Total percentage spent directly on project
82%
10
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
1.9. Acknowledgements
This study was conducted by Biosphere Expe
ditions
,
which runs wildlife conservation
expeditions all over the globe. Without our expedition team members (listed above) who
provided an expedition contribution and gave up their spare time to work as research
assistants, none of this research would ha
ve been possible. The support team and staff
(also mentioned above) were central to making it all work on the ground. Thank you to all
of you and the ones we have not managed to mention by name (you know who you are)
for making it all come true.
Biosphere
Expeditions would
also like to thank
the Friends of
Biosphere Expeditions for their sponsorship and/or in
-
kind support.
The author
would like to thank the Namibian Government, the Namibian Tourism Board
and the Ministry of Environment and Tourism in parti
cular, for giving me the permission to
conduct this study. My thanks also
go
to all expedition team members as well as staff
members for
their amazing effort and their
contribution to the
research
on Okambara.
My
thanks also go
to Swaro
v
ski
Optik for provi
ding
binoculars and range finders
.
I thank the
Institute for Zoo and Wildlife Research in Germany for scientific advice
, help with handling
and immobilisation of animals
and analysing blood samples.
My s
pecial thanks go
to
Uschi
and Christian Schmitt
, for
giving me permission to run the expedition on their property
and
for their cooperation
and allowing me to live on Okambara.
Also
,
I would like to
thank Alisa
Clickenger for running the expedition on the ground
and her support on numerous
occasions. I
thank
Matthias Hammer and the other reviewers for their comments on
various versions of this manuscript.
Last but not least, I would like to thank Biosphere
Expeditions for the contribution that this expedition has made to large
carnivore
conservation
in Namibi
a
.
1.10. Further information & e
nquiries
More background information on Biosphere Expeditions in general and on this expedition
in particular including pictures, diary excerpts and a copy of this report can be found on the
Biosphere Expeditions website
www.biosphere
-
expeditions.org
.
Copies of this and other expedition reports can
be accessed via
www.biosphere
-
expeditions.org/reports
.
Enquire
s should be addressed to Biosphere Expeditions
via
www.biosphere
-
expeditions.org/offices
.
11
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Please note: Each expedition report is written as a stand
-
alone document that can be read
without
having to refer back to previous reports. As such, much of this section, which
remains valid and relevant, is a repetition from previous reports, copied here to provide the
reader with an uninterrupted flow of argument and rationale.
2. African leopard
ec
ology
on
a
Namibian game farm
Vera Menges
Biosphere Expedition
s
2.1. Introduction and background
Given the steady decline in biodiversity, it is of increasing importance to connect nature
conservation with science
-
based management (
Lawler et al. 2006, S
oulé & Orians 2001
).
Research
not only
serves to broaden scientific knowledge, but is
also
essential
for
predicting the success of
management plan
s
for
species.
This is especially true for large
carnivores as they are at the top of the food chain in terres
trial ecosystems
,
but at the
same time represent
its
most vulnerable elements
(
Schipper et al. 2008
). Studies indicate
that ca
rnivores play an essential role
as they structure
as well as preserve the existing
biodiversity through
their prey choice
(
Miller
et al. 2001
). The elimination of carnivores
can
lead
to a
chain of negative consequences
, starting with the demographic exp
losion of
herbivores and meso
-
carnivores
and
unsustainable
grazing
pressure, leading to
biodiversity loss at all levels of the food c
hain
,
and
it
can even
result
in a collapse of the
ecosystem
(
Estes
& Duggins 1995
, Henke & Bryant 1999
). It is therefore crucial to protect
apex predators
,
in order to
pres
erve biodiversity
as well a
s the ecosystems that host them
.
Research
on
carnivores
is usually
not very
practice
-
oriented and management guidelines
are often intuitive and subject to trial
-
and
-
error methods
,
rather than relying on scientific
facts (
Ray et al. 2005
). However, species
-
specific knowledge of ecology and biology of a
species
i
s required
for the successful implementation of wildlife
conservation
and
management (
Frankham et al. 2002
).
T
hus the probability of success of the
applied
methods
increases
and important resources
, such as time and finances, are
used more
effectively.
In
Africa,
human
wildlife
conflicts
are
among the three
main
threats to
the
existing biodiversity;
in
particular
for large cats such as
the l
eopard
(
Panthera pardus
)
(
Nowell & Jackson 1996, Ray et al. 2005, Treves & Karanth 2003, Woodroffe 2000
).
Several stu
dies on
leopards (
Panthera pardus
)
exist already
, but
they were usually carried
out
in protected area
s such as Kruger, Serengeti and Etosha National Park
s
(
Bertram
1982, Bailey 1993, Stander 1997
, Durant 1998,
Mizutani 1999, Ray et al. 2005
)
. However
,
the
majority of leopards
in
Namibia
occur
on
commercial
farmland.
There, t
he local
farmers are often accused of
persecuting
big c
ats to protect their livestock. Such
behavioural patterns are
primarily due to
the
absence
of
basic strategies to avoid conflicts
w
ith these animals in
the first place
(
Linnell et al. 2001, Marker et al. 2003
).
Namibian
farmers
are organis
ed
locally
in
to
so
-
called
conservancies in
which they develop and
agree on
management guidelines. Since there is often a lack of information on the
ecology
and biology of the big cats, the
se
management guidelines are
often
neither sustainable
,
nor
do they
solve problems
comprehensively.
M
ost
of the local farmers
are engaged in
breeding
cattle
and also
use the locally abundant
wildlife for their own co
nsumption
as well
12
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an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
as for
trophy hunting.
L
osses
due to predators
are
reported regularly; some
farmers have
particularly
high
losses
,
which
put them
under high economic pressure
,
and
are
therefore
intolerant of b
ig cats and other predators
(
Shwiff & Sterner
2002, Hughey et al. 2003
).
There are no detailed studies on the prey preferences
of leopards
outside
protected
areas.
Farmers often assume that leopards
specialise in preying on domestic livestock and take
calves, sheep, goats and poultry as easy prey
.
P
e
rsecution
of leopards
and their
extermination
on farmland with methods
such as hunting at night with torches, the use of
dogs to chase the cats or shooting them in a box trap is putting the local leopard
population under threat.
To understand the ecologic
al factors that determine demographic trends in carnivores, it is
important to study free
-
ranging populations under natural selection pressure. As most
parts of Namibia are under some sort of agricultural management, which very often entails
removal of pro
blem animals, the selection pressures include human factors. Demographic
parameters such as fecundity, mortality, reproductive success, sex ratio, age structure and
social structure
can
therefore differ from populations in protected areas. These
demographi
c parameters are key elements to estimate long
-
term viability of populations,
and population viability models need to be fed with high
-
quality data as the output of these
models is extremely sensitive to the input. Information on leopards on commercial
far
mlands is scarce and very often preliminary data are used.
Large carnivores are particularly difficult to study, as they range widely, occur at low
densities, capture probabilities
vary
between different individuals, and they are often
secretive or elusiv
e (
Karanth 1995, Boulanger et al. 2004
).
Leopards in protected areas,
for example in national parks, are habituated to humans
. Therefore
extended periods of
observation are possible. However, leopards living on commercial farmland generall
y
avoid encounter
s with humans.
To obtain high
-
quality data, indirect sampling methods are
required. Fitting individual animals with GPS collars is a su
itable method to study solitary
and
elusive
mammals
in their habitats (
Seidenst
icker et al. 1970, Bailey 1974
) as the dat
a
obtained provide information on home range sizes, movement patterns
and
habitat use.
Information gleaned thus can be incorporated into farm management and may help to
keep financial losses to a minimum, which in turn makes cooperation by stakeholders
mor
e likely.
Also, m
onitoring the abundance and distribution of animals is fundamental to the research,
management and conservation of wildlife populations.
Estimating animal numbers is often
a basic requirement for
determining the status of species. However
, this task is deceptively
simple and no single best approach exists; techniques that work
well in some situ
ations
are useless in others (
Caughley and Sinclair 1994
)
. Many terrestrial
mammals
such as the
leopard
are nocturnal, cryptic in appearance, and
, i
n the case of leopards on farmland,
generally
adept at avoiding being seen, which limits well
-
developed methods
of direct
observation
(
Duckworth 1998, Chiarello 2000, Lopés and Ferrari 2000, Jachmann 2001
)
.
These
challenges leave indirect observation, for
example via animal
tracks or remote
photography, as often the only realistic option.
Photographic capture of individual leopards,
together with information on date, time and capture location, can provide baseline data for
population density analyses (
Karan
th et al. 2004
). Photos obtained can be used to identify
individual animals and add valuable information towards population density est
imates and
population dynamics.
In
general, recordings of predator tracks are designed to provide
presence/absence data o
nly, but by following tracks of foraging cats, a wide range of
additional data about behaviour such as prey
-
encounter frequencies, hunting success,
13
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
prey species selection, home range use and social interactions can be gathered (
Stander
et al. 1997
). Scats
of predators add another piece of evidence of predator occurrence. The
hair of prey is relatively
indigestible
and
undamaged
in most carnivore scat and can thus
be used to identify the prey species eaten (
Wachter et al. 2006
). Scat analysis is used to
unde
rstand the prey preferences of leopards and obtain insights into predation habits, thus
showing
if diet overlap and potential competition among carnivores and even smaller prey
occurs.
In addition,
prey preferences
can further be
evaluated
through
GPS
clu
ster analysis
. This
is a
fairly
new method to detect
potential kill sites
of carnivores and has been applied only
in a few studies (
Krofel et al. 2012, Pitman et al. 2012, Fröhlich et al. 2012
)
.
Leopards
revisit kill sites for up to several days in order t
o fully consume their prey, thereby leading
to
a specific pattern of GPS locations ("clusters"
). Remains found at these locations can be
used to identify prey species and therefore provide information on individual prey
preferences of leopards.
Such findin
gs are very important to demonstrate predator dietary
preferences and thus enable game ranchers to manage predators on their land.
The abundance and density of prey species are influencing factors on predator
occurrence
,
densities
and prey preferences
and
therefore need to be investigated as well.
In addition, t
he management of game
species on game farms is an
important factor in
securing income.
In areas w
here wild ungulates are utilised by people for either
consumptive
purposes
(commercial hunting and ga
me farming) or non
-
consumptive
purposes
(safari tourism), competition and conflict may occur between game ranchers and
large predators. With the advent of game ranching, game prices for most species have
increased by more than 50% over the last 20 years. M
any game farms are stocking up
with rare and valuable species such as roan (
Hippotragus equinus
) and sable
(
Hippotragus niger
) antelope, resulting in a large increase in the antelope value over
recent years. The typical game farm is fenced to keep the valu
able game species on the
property of the owner. Historically, game migrated perennially from one grazing ground to
another. This gave the grass time to regrow, bloom and reproduce. Fences hinder these
dynamics and game farms run the risk of severe degradat
ion and desertification due to
overgrazing. Management therefore becomes crucial in fenced
-
in area
s
and many pieces
of information are needed for successful management,
such as
game density,
reproduction rate, primary production and sustainable stocking ra
tes.
To determine the status of the leopard population in the study area, the dynamics and
abundance of the leopard population and prey species
need to be ascertained. The
basic
questions that the study focused on were: What is the behaviour and ecology o
f leopards
living on commercial farmland, particularly game farms? Are there any differences to
leopards found in protected areas and national parks?
What is
the local
prey availability
and abundance?
14
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
2.2. Study site and training of
expedition participant
s
Okambara
is situated
85
km
south
east
of
Windhoek’s
Hosea Kutako
International A
irport
(F
igure 1
.2
a
). The farm is 15
0
km² in size and entirely
surrounded
by a game
fence
(height
4
m)
(F
igure 2.3a
)
. All internal fences have been removed, thus allowing fre
e roaming of
wildlife
(in F
igure 2.3a
turquoise
lines inside the
study area illustrate
former fence
lines
as
the
study area eight years ago consisted of three
different farms
“Frank” in the south,
“Bildah” in the
centre
and “Okambara” in the northwest)
.
The
study site
has
a variety of
landscape
s
(altitude
s
range from 1
,
500
to
2
,
000 m) with many different habitat types
ranging from typica
l
African bushveld to
mountainous
areas
, and it
contain
s
ideal habitats
for all of Namibia’s indigenous mammal species,
including elephant and rhino.
Fairly
evenly distributed over the study area
are
nine
dams (man
-
made lakes), which contain
water year
-
round
.
Other dams
are relatively small and only keep water for a few months
after the
rainy season.
The area
has not been u
sed
for any commercial farming activity
for
many years
,
thus leaving the pasture and bush in
good
condition. The
expedition base
camp site (S
22.44308
,
E
16.96900)
is
situated close to
a man
-
made waterhole called
Gustavposten
.
Okambara
is a
good
ar
e
a
in w
hich
to study
leopard
ecology in a game farm
setting.
Although the
study area
is fenced
in
, the movements of leopards and other felids are not
confined as cats (
as well as other predators
and smaller herbivores) can easily
pass
underneath the fences.
For
the first two days
of each
two
-
week
group
,
expedition participants
were given talks and
practical lessons, learning the use of GPS
, compass,
range finder and other research
equipment
and safety techniques, skills and procedures.
F
irst excursions into the
field
were under the supervision of Biosphere Expeditions staff. After a few days,
participants
were
able to navigate around
the study site, install camera tr
aps,
rec
ord tracks and signs
of mammals and
identify animals. Where necessary
,
research teams were
accompanied
by trained local
staff
t
o improve the accuracy of data recording
or to provide a safe working
environment. Data entry and p
icture downloads were tasks performed at the expedition
base
.
2.3. Study animal
The leopard
(Panthera pardus)
was the
key study species
.
It has the greatest geographic
distribution of all the
big
cats (
Nowell and Jackson 1996
), covering a variety of different
habitats ranging from desert to rainforest. Density varies with habitat, prey availability and
intensity of per
sec
ution, from
below
one
individual
to over 30
per
100 km², with
the
highest
densities
recorded
in protected east
ern
and southern African environments (
Hunter 2011
).
Nevertheless, the leopard is listed
o
n Appendix I
of
CITES and
is
classified as Near
Threaten
ed (
IUCN 201
3
)
, with nine genetically distinct subspecies. Currently wild cats
such as leopards, cheetahs and caracals are not listed in the Endangered category (
IUCN
20
13
)
al
though excessive trophy hunting
combined with a high “problem predator” take
-
off,
and other factors such as habitat loss, fragmentation and local outbreaks of wildlife
diseases, may potentially put the leopard (and the other predator species) under threat
locally
(
Berry 1990,
Bailey 1993
).
15
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-
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-
profit
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or
ganisation registered in England, Germany, France, Australia and the USA
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.
3
a
.
Okambara
Game Reserve
con
sists of three former farms as shown by the red lines that surround farm
roads (yellow).
The outer red line perimeter is an electrified game fence
;
inner fences (turquoise) have been removed.
16
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an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Leopards are
solitary, nocturnal carnivores
with spacious home
ranges, but only occur in
low densities (
Spong et al. 2000
).
Both sexes are territorial and defensive against
adult
conspecifics of the same sex
;
they mark their territory with scent, faeces and scratch
marks
(
Hamilton 1976, Bailey 1993
)
.
Leopards are very
good climbers; they often hide
their prey in trees to avoid scavengers.
Their hunting strategy consists of
stalking and
pouncing
;
thus
they do not chase their prey over long distances
(
Bailey 1993, Stander et.
al 1997
)
.
Leopards have a vast range of prey;
Bailey (1993)
noted at least 92 prey species
used by
leopards in sub
-
Saharan Africa,
varying from species as small as the dung beetle
up
to large mammals
such as
adult male eland
antelope
s (
Kingdon 1977
). Yet despite this
apparent ability
to
successfully
exploit prey spanning such an enormous size range,
the
leopard
’s
diet is generally dominated by medium
-
sized ungulates (e.g.
Bailey 1993
). A
recent analysis of 33 studies on leopard feeding ecology revealed that leopards
preferentially prey upon species wi
thin a weight range of 10
40 kg, even if prey outside
this weight range is more abundant (
Hayward et al. 2006
). The optimum prey weight for
leopards derived from this analysis is 23 kg, based on body mass estimates of significantly
preferred prey species (
Hayward et al. 2006
).
2.4
.
Methods
2.4.1
.
Capturing and collaring
Box traps were
baited mainly with antelope as well as
zebra meat
and
were
checked
twice
a day (morning and
late
afternoon). Once a target
animal
, i.e.
a
predator,
was captured, it
was dar
ted and
immobilised
. Drug choice, dosages and combinations depended on
the
type of species captured and the body weight. Whilst under anaesthesia, animals were
placed in a shaded
location
and a facial cover and eye lubricants were used to prevent
damage to
the eyes. Noise levels were kept to a minimum. Vital parameters were
monitored and an intravenous line was placed to administer fluids if needed and to have
access to the bloodstream should an emergency arise. ID pictures were made from
both
sides of the
animal for usa
ge
in
the camera trap survey (F
igure 2.4.1a
). Various samples
were taken (a range of blood samples, smear of saliva, nasal and conjunctival fluid, faeces
and body measurements). While working in the field, blood samples were stored
,
chilled
a
nd processed later in the lab
oratory
. The animal’s age was determined based on
tooth
wear and general habit. Only f
ully grown animals were fitted with a GPS collar.
Once the anaesthetic was reversed, the animal was
placed at a location in the shade near
t
he handling si
t
e and observed from a safe distance
to ensure complete anaesthetic
recovery
.
Both
e
-
o
bs GPS
-
collars
(Figure 2.4.1
b)
and
Vectronic Aerospace
satellite
collars
were
used.
These
collar types
provide the GPS position (
based on the coordinate system
WGS84
) of the animal, a fine
-
scale ambient temperature and
an activity
measurement;
the Vectronic
collars
also send a
notification in the event of mortality.
D
ata collected by the
collars were downloaded
at
regular intervals via
airplane
telemetry.
The weight of
each
co
llar was less than 3% of the animal
’s body weight.
17
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.4.1a
.
ID picture
of
fe
male leopard
L074
, left
side
.
Figure 2.4.1
b.
Taking samp
les of adult female leopard L074.
18
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
2.4.2
.
Monitoring animals
h
ome range
GPS
(Global Positioning System
)
tele
metry
was used
to monitor the animals’ home
ranges
.
Leopards fitted with collars were located by GPS
;
i.e. the transmitter inside the
collar atte
mpts
within defined intervals
to contact at least three satellites in order to
determine accurately the ani
mal’s position
.
Telemetry data
were uploaded to
movebank.org
and converted into ESRI shape files and
c
sv
-
files for further analysis
. Afterwards data were entered into
the statistical program R
and the geographical processing program ESRI ArcGIS 10.1 to calculate and display
home range sizes
. The home range size was calculated using two standard methods: th
e
minimum convex polygon (MCP,
Hayne 1949
) and the kernel method (
Worton 1989
).
Data analysis
The MCP method is one of the earliest and still a widely used method for calculating home
ranges (
Harris et al. 1990
). In this method the peripheral locations o
f a given data set are
connected so that they form a polygon. The MCP method is very simple and the resulting
home ranges are comparable between studies, but it has several disadvantages. For
example, the home range is highly correlated to the number of lo
cations and it does not
give any informat
ion on how the area is used
. Studies on habitat utilisation require more
sophisticated analyses such as the kernel method. Currently th
is
method is considered to
be the most suitable one for home range estimation (
P
owell 2000, Worton 1995
). With
it
a
probability density function from the locations is calculated in order to determine a utility
distribution. Home ranges are then defined by drawing contours around areas with equal
intensity of use. The home range looks
like a hilly surface. However, occasional
exploration trips of an animal may lead to overestimated home range sizes. To correct for
this, a certain percentage of the data
set is excluded as outliers (e.g.
5% of the most
remote points being excluded results
in the
Kernel 95
). From a biological point of view, the
kernel method is much m
ore useful than the MCP method,
but for comparison with
previous studies MCP data needs to be considered too.
2.4
.
3
.
Track
counts and scat collection
Twelve
different routes
were planned for track and scat counts (total 70
km)
(Figure
2.6.
4a)
. Each day, a route was selected randomly. Occasionally expedition team members
needed to reschedule for safety reasons because elephants were utilising that particular
area. GPS positions
were recorded for all leopard, cheetah and hyaena tracks found. Data
such as date, number of animals, sex and age class, age of track (very fresh, fresh, old,
not sure) and track size (pad width, pad height, total width, total length), direction of track,
start and end point of the track and further comments were recorded.
All leopard, brown
hyaena and cheetah scats found on the transects were collected. Scats were collected
along the same routes as tracks, and date and GPS coordinates were noted. Scats
co
llected were air
-
dried and stored. Leopard scats can be discerned from scats left by
other species by their size, shape, consistency (
Stuart and Stuart 2000
), odour and
adjacent tracks visible. In terms of size, hyaena scats are similar to leopard scats, b
ut
they
are
easy to distinguish from them, as hyaena scats are much harder and white due to a
high ratio of calcium residue of digested bones (
Walker 1996
). Additionally, in many cases
tracks were found in association with scats, which ma
de identification
more precise.
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-
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-
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
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nion for the Conservation of Nature
2.4.4
.
Camera traps
Results from the capture
recapture methods can be analysed by the program
CAPTURE
(
Otis et al. 1978, Rexstad & Burnham 1991
).
This
program
offers
diffe
rent
models
to
calculate
population size
.
Two different brands of camera traps (
Bushnell
Trophy Cam 2010 & 2011 and
Reconyx
650) were used during the study. Both were equip
ped with SD memory cards up to 8 GB
(yielding up to 8
,
000 pictures at medium resolution settings). Camera traps were
either
positioned in wildlife hotspots close to natural or man
-
made water sources or scattered
over the study site
,
mostly alongside farm t
racks.
The minimum distance between stations
was 700 m and the maximum distance was 15 km.
Camera traps were checked
once
a
week to exchange SD cards, make minor adjustments and verify battery status. Leopard,
brown hyaena and cheetah individuals were iden
tified from the pictures taken, as well as a
host of other non
-
target animals (primates,
ungulates, etc.). The fur pattern
of each
individual
leopard and cheetah
is unique and individual animals were identified. Brown
hyaenas have stripes on the front legs
as well as scars on the face or ears, all of which
can be used to identify individuals.
The program
Camera Base
(Version 1.6
,
Tobler 2010
) was used to organise camera trap
pictures and r
un analyses, for example via the program
CAPTURE
(
Rexstad and Burnham
1991
), which estimates
leopard abundance.
CAPTURE
offers
different
models
and
identifies
which model fits the data se
t best and then generates capture statistics for all
models (
Jackson et al. 2006
). The most important statistical requirement to calculate
population size based on mark
recapture data is the assumption that the population is
closed (no immigration, no emig
ration, no mortality and no birth) during the sampling
period.
To meet this requirement, a sampling period between 30 and 90
days should be
considered, so 9
0 days was chosen for this study. If an animal was photographed it was
noted as an event. In order
not to overestimate the research area, a buffer needed to be
added
.
To estimate the area effectively sampled (A), a convex polygon connecting the
outermost camera traps plus a buffer area, where width (W) is an estimate of half the
home range length for fe
male leopards in the sampled area, was computed following
Karanth and Nichols (2002).
Population density was determined by dividing numbers of
identified leopards (by CAPTURE)
by
the sampled area.
2.4.5
.
GPS c
luster
a
nalysis
Based on
temporal high
-
resol
u
tion
GPS data of collared leopards,
a GPS cluster analysis
was performed
(
Pitman et al.
2012
, Fr
ö
hlich et al.
2012
).
Leopards
feed from
their prey
repeatedly, thus returning to the
carcass
(
i.e. hiding place where the prey is located
)
over
a period of
up t
o
several days. This causes a cluster pattern in the data, meaning
numerous GPS positions (of consecutive days) in the same location
(see Figure 2.4.5)
.
Detected clusters were visited in the field and searched for prey remains such as hair and
bones
,
which
were then
used to identify the prey species.
20
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-
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-
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ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.4.5
a
.
GPS
positions, movements and cluster (yellow circle) of L05
5
as an example
.
2.4.6
.
Game counts
V
ehicle game counts and waterhole observations were conducted over a four
-
month
period. Of pri
mary interest was population demographic data (e.g. male:female ratios, age
composition of herds, number of sexually mat
ure females with calves, etc.).
Distance
sampling is one of the best methods to estimate wildlife populations accurately (
Buckland
et al
. 2008
). For this purpose the study area was divided into line transects following
Buckland et al. (2008). The area was classified into two easily discernable vegetation
types: dense and open.
Vehicle game counts were conducted on farm tracks. The three t
ransects of between 10
and 15 km
(see Figure 2.4.6
)
each were driven along at a very low and relatively constant
speed (about 15
20 km/h) and observers on the back of the vehicle counted all animals
they detected on both sides of the road. All game animals
within a 1
,
000 m semi
-
circle (the
average viewing distance on foot) in front of the observers were counted
.
Equipment used
included range
finder, binoculars, angle measurer, clipboard, datasheet, pen and different
African mammal identification field guide
s. Species, number(s), distance
to the vehicle
and
angle of the detected animal(s)
from the transect (vehicle midline)
were recorded, as well
as the GPS position of the observer, plus, if possible, any notes about
the
species
age
and sex
.
21
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.4.6
a
.
The three vehicle game count routes on Okambara.
VGC 1 = 10.8 km, VGC 2 = 14.9 km and VGC 3 = 12.7km
.
22
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-
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-
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or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
G
ame species were also recorded
at waterholes
. At the beginning of the study, expedition
participants had to construct several hides at each waterhole
so that viewing positions
could be taken up depending on the wind direction. Observations took place during the
day to study animal behaviour such as duration of stay at the waterhole, and whether
animals were drinking or not. Gender, age class and herd c
omposition were also recorded.
2.5
.
Results
2.5.1. Capturing/collaring
The capture campaign started
at
the beginning of
August and continued until
the
beginning
of November 2014
. During this period
one juvenile male leopard, one adult female leopard
and
one
adult male leopard
were captured
(L073, L074, L075 respectively
)
.
All leopards
wher
e captured in baited box traps and
immobili
s
ed
. The
female
leopard
was
fitted with
an
e
-
o
bs
GPS collar and the adult male leopard was fitted with the Vectronics satelli
te collar
.
The juvenile male leopard was too young to be collared.
All individuals captured were in
good condition (Table 2.5.1a
).
During the expedition
four to
six
box traps were set throughout the study site.
Since the
fifth
and the sixth box trap were
a loan of the IZW,
their
availability was dependent
on the
needs of the insititute and
were
therefore not available throughout the whole expedition.
Each trap that
was
set count
ed
as one trap night. One night with four
,
five
or six
armed
box traps
was
ther
efore counted as four
,
five
or six
trap nights
, respectively
. During the
study per
iod box traps were active on 94
days with a total of
586
trap nights
(T
able
2.5.1b
).
When checking the traps,
88
%
of box traps were found open, 5% had captured an
animal and
7
% of the traps that had shut were empty (F
igure 2.5.1
b
). Three
leopards, one
honey badger
(
Mellivora capensis
)
,
one
small
-
spotted
gennet
(
Genetta genetta
)
, one
slender
mongoose
(
Galerella sanguinea
)
, two
African savannah
hares
(
Lepus microtis
)
,
two
wartho
gs
(
Phacochoerus africanus
)
,
twelve
crested
porcupines
(
Hystrix cristata
)
, one
rock
monitor
(
Varanus albigularis
)
and one
red
-
billed
francolin
(
Pternistis adspersus
)
were
captured
. Traps were set in
eight
different locations; the highest capture success wa
s
close to the
farmhouse of the farm owner (BT02) in the northern middle
of the study site
(trap
position BT04
on Figure 2.5.1b
)
.
Table 2.5.1a
.
Predator
capture
data 2014
.
Capture
d
ate
Species
Animal
ID
Gender
Estimated
a
ge
Weight
(kg)
Neck
circ.
(cm)
C
o
llar
24.08.20
14
Leopard
L073
M
ale
10 months
18
30
no
25
.08.20
14
Leopard
L0
74
F
e
male
5
40
40.5
yes
27.09
.2014
Leopard
L075
M
ale
5
63
58
yes
Table 2.5.1b
.
Trap nigh
ts (24h) effort and success 2014
.
Trap nights
Open
Closed
but
empty
Capture
58
6
516
42
2
8
23
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-
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-
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ganisation registered in England, Germany, France, Australia and the USA
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.5.1a
.
Captu
re success from 584
capture nights (24h) on Okambara in
2014
.
During the capture campaign traps wer
e moved regularly. In Figure 2.5.1b
, the
letter “A”
after
labels of box traps (e.g. BT01)
indicates a new po
sition of a box trap (
Figure 2.5.1b
;
for example
,
box trap 1, BT01, moved to location box trap BT01A).
2.5.
2
.
Home range size
Data from leopards collared in 2013 is included.
The MCP of L051 covered an area of 413.72 km²; Kernel 95 consisted of 383.73 km²,
Kernel 90 of 356.1
8 km² and Kernel 50, the core area of the home range, was 119.75 km².
L052 had an MCP of 269.29 km² whilst Kernel 95 and Kernel 90 covered an area of
202.45 km² and 174.82 km², respectively. The core area of L052 (Kernel 50) consisted of
65.84 km². The MCP
of L055 was 172.63 km²; Kernel 95 covered 145.01 km² and Kernel
90 entailed 119.38 km². The size of the core area of the home range of L055 was 53.31
km². The MCP of L074 covered an area of 37.91 km²; Kernel 95 consisted of 34.72 km²,
Kernel 90 of 29.63 k
m² and Kernel 50, the core area of the home range, was 12.04 km².
L075 had an MCP of 89.63 km² whilst Kernel 95 and Kernel 90 covered an area of 82.29
km² and 73.82 km², respectively. The core area of L075 (Kernel 50) consisted of 49.56 km²
(see Table 2.5.
2).
Table 2.5.2
.
Home range size (km
2
; MCP and Kernel) of the leopards collared on Okambara
.
Home range size (km
2
)
L051
L052
L055
L074
L075
DATA
256 days
343 days
253 days
59 days
37 days
Kernel 50
119.75
65.84
53.31
12.04
49.56
Kernel 90
356.18
17
4.82
119.38
29.63
73.82
Kernel 95
383.73
202.45
145.01
34.27
82.29
MCP 100
413.72
269.29
172.63
37.91
89.63
24
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-
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-
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O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.5.1b
.
Map of
Okambara with
position of box traps
in
2014
.
25
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.5.2a
.
Location
s of all collared leopards
on Okambara
and surroun
ding farms since collaring
.
26
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-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.5.2b
.
MCPs
of all collared leopards on Okambara
.
27
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-
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-
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
2
.5.
3.
Track
counts and scat collection
Track
and scat
routes were
monitored
between
one
and
6
times
each
and a total length of
294.2
km was
covered
.
Eight
of the rou
tes
were in the plain
s
area
(2, 5, 6, 7, 8, 9, 10 & 11)
and
five
in mountainous areas
(1, 3,
4
, 12 & 13
). The routes
most frequently
monitored
were number
s
3,
4, 6 and
9
.
Number
s
2, 7
and
11
were not
monitored
regularly
,
because
elephants
were in those are
as
frequently
.
Figure 2.5.3a
shows the probability (p %) per kilometre of predator findings (tracks/scats)
for
leopard, brown hy
aena and cheetah
on differ
ent routes (T
racks
&
S
cats Route No.
1
13
).
Figure 2.5
.3a
.
Probability
p (%
)
/km of predator occurrence on the basis of track and scat findings
on particular routes
. LEO = leopard, BH = brown hyaena, CH = cheetah.
Leopard
signs
(43
)
dominate
d
the results over
cheetah (10
)
.
Hyaena signs
(18
)
were
found
all over the study site
, sometimes several times in the same location.
T
h
e largest
number
of tracks and scats from leopard
s
were found close to
the edge of
the
small mountains in the north and
southwest
of the study site,
where
there is also
water
available
(route
s
3 & 6
).
Also
, on route 1 and 9
sever
al signs of leopards were found.
Few
signs of leopard occurrence were detected on routes 2, 4, 5, 10
, 12
and 13. No signs of
leopards were found on routes 7, 8 and 11, all of w
hich are situated in the plains (see
figures
2.5.3a,
2.5
.3b and 2.5.3c).
Signs of
hyaena were found mostly on route
s
4, 6,
12
and 13
; few
signs were detected on
routes 1, 2, 3, 7
and 1
0.
No signs of hyaena were found on routes 5, 8, 9 and 11.
Only on
routes 3, 5
, 7, 8, 9 and 11
were
signs of cheetah occurrence
detected
(see figures
2.5.3.a,
2.5.3b and 2.5.3c).
28
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-
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-
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Figure 2.5
.3
b
.
Amount
of scats from different predators on fixed
survey
routes
, O
kambara
2014
.
L
eo
= leopard, BH = brown hyaena, CH = cheetah
.
Figure 2.5
.3c.
Amount
of tracks from different predators on fi
xed survey routes, O
kambara
2014
.
L
eo
= leopard, BH = brown hyaena, CH = cheetah
.
29
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-
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-
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ganisation registered in England, Germany, France, Australia and the USA
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
2.
5.4. Camera traps
The study period started at
the beginning of August 2014
.
F
ifteen
c
amera traps were
place
d at strategic points (based on
tracks and scats, near waterholes
) around the study
site.
Due to logistics, all available camera traps were not set on one single day in the field
but on several consecutive days.
Overall, between
5
and 14
camera traps were
in use
at
the same time
throughout the whole expedition
(number of camera traps increasing with
each additional day in the field during the first slot)
.
Not all leopard
s photographed could
be identified. From
42
events
,
17
% of photographs were either too p
oor in quality
(e.g.
blurred or overexposed
) for
the fur pattern
to be sufficiently visible,
or close
-
ups showed
only small body sections. In total
3
9
useable
leopard
events were recorded
throughout the
whole expedition
, wh
ere an event is a picture with as
a certain
individual
identifiable
leo
pard captured by a camera trap.
Capture success
A
sampling
period
of
9
0 days was set and conducted
fr
o
m
07
August to 05
November
2014
, yielding
34
events
.
Nine
individual
adult leopards were identified
by their coat
patterns
. Four
adult males
were recorded
;
two of which
had been
captured and
collared in
2013, one male
w
as
captured and equipped with
a collar
during the study period.
In
addition,
two
mature females were photographed on several occasions
.
Further, two mo
re
individuals were recorded whose sex could not be identified.
Table 2.5.4
a.
Camera
-
trapping
effort and leopard captures 2013
and 2014
.
Sampling
period
Trap
stations
Photos of
leopards
Identified
individuals
17 Aug
15 Nov 2013
1
4
29
6
07 Aug
0
5
Nov
2014
1
4
34
9
During the sampling period,
14
camera traps were active,
nine
of which recorded leopard
s
.
Six
cameras
recorded brown hyaena
; pictures were not clear enough to identify
individuals
.
Events of pictures taken of other predator
s
within the
study period are listed in
Table 2.5.4
b
.
Table 2.5.4
b
.
Number of c
amera trap pictures of different predators
2013 and 2014
.
Sampling
period
Brown
hyaena
Spotted
hyaena
Honey
badger
Caracal
African
wildcat
Jackal
17 Aug
15 Nov 2013
4`
2
8
9
12
45
07
Aug
05
Nov
2014
34
0
11
5
13
32
30
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-
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Estimates of leopard capture probability, population size and density
The CAPTURE test for closure supported the assumption of population closure (i.e. no
immigration, emigration, births or deaths) during the survey. C
APTURE selected the null
model (M
0
) for the survey. A relatively high captu
re probability of 0.
4271
was recorded (
the
probability that a leopard in the sampled area is photographed on a single sampling
occasion)
(Table 2.5.4
d
).The sample population was est
imated to be
eight
leopards (SE
±
0.
4827
, 95% CI
6
-
6
). When computing the 95% confidence interval, CAPTURE converts
the values to the nearest integer, rather than printing decimals (
Jackson
et al
.
2006
).
For the survey
eight
individual leopards (excluding
subadults) were e
stimated to occupy an
area of
104.93
km
2
. The buffer width (half of the home range length of a female home
range) was 4.4 km.
The estimated effective area sampled
was 318.52
km
2
. A density of
1.8
individuals per 100 km
2
was calculated.
T
able 2.5.4
d
.
Results of population closure, capture probability, estimated abundance, standard error and 95%
confidence interval of leopards sampled on
Okambara game farm, Namibia
,
in
2014
.
Null Model (M
0
)
Test for closure
Capture probability
Abu
ndance
(SE)
95% CI
z = 0.
592
P = 0.
6
71
0.
42
71
8
±
0.
4827
7
-
7
2.5.5. GPS
c
luster
a
nalysis
The GPS c
luster analysis
bas
ed on the data of L051, L052,
L055
, L074, L075
showed
no
specialisation of individual leopards.
Prey species varied
among
eight different spe
cies
(see
F
igur
e 2.5.5). At 33
% of the visited kill sites, remains of greater kudu were found.
Thirty
percent
of the kill sites revealed remains of
oryx
,
and at 14
% of the kill sites remains
of
impala
we
re detected. Remains of warthog
were
found at 7
% of k
ill
sites and at 4% of
the kill sites, steenbock was found. Mountain zebra and
cattle were
each
fo
und 3% of the
kill sites, respectively. Waterbuck, horse and porcupine were also found, each of which
constituted of 2% of the kill sites.
Figure 2.5.5
.
Prey range of leopards
(
%
of kill sites)
on Okambara and surrounding farms
.
31
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fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
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2.
5
.
6
.
Game counts
Vehicle game counts were conducted
during daylight hours
between August and
Novem
ber 2014
using
three
line transects
(see F
igure 2.
4.
6a)
and distance sampling
methods. All routes were driven from south to north and started at the same time in the
morning (
at
sunrise).
There was a tracker or
a
scientist on each game count vehicle to
provide some standardisation of observations and
increa
se
detection probability.
The three transects lengths were VGC 1 = 10.
8
km, VGC 2 = 14.9
km and VGC 3 = 12.
7
km.
Twelve
game counts were
conducted, yielding
3
,
694
animals
over
460.8
km
driven
.
Results of counted animals from the three transects were exami
ned over the entire area
(150 km
2
). Livestock animals such as cattle, horses and donkeys were not counted
.
Re
sults are listed in Table 2.5.6b
.
Over
time, the same groups, e.g.
brindled gnu
(blue wildebeest)
and white
-
tailed gnu
(black wildebeest)
, were ob
served repeatedly in certain areas of the farm (e.g. on VGC 3).
Animals were
relatively easy
to detect, because they prefer to stay in large groups in open
areas to feed on grass.
Results of the waterhole observations at
seven
different waterholes (F
igure
2.
3
a;
Bergposten, Frankposten, Gustavposten, Sandposten
, Michael’s Dam
, Lodgeposten
and
Boma
) produced
737
animals over
171
sightings. The percentage of juveniles was
8
.55
%.
The study period was between August and November
2014
.
Some
of the time animals
n
oticed the observers in the hide,
but more than 90
% did not flee.
The total numbers of
obser
ved game species are listed in T
able
2.5.6
a
.
Table 2.5.6a
.
Total n
umbers of
observed
ga
me species at waterholes on Okambara in 2014
.
Species
Total
White
-
Tailed G
nu
21
Brindled Gnu
23
Eland
45
Giraffe
28
Impala
277
Greater Kudu
67
Oryx
24
Mountain
s Zebra
45
Sable Ante
lope
13
Springbuck
1
Warthog
113
Waterbuck
80
Total
737
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Table 2.5.6b
.
Numbers of
observed
ga
me species
(
total no. of
individuals
seen on
vehicle game counts during
expedition period
, mean
number
of individuals observed on vehicle game count during expedition period (total
number/num
b
er of game counts carried out)
,
individuals
/km
2
(mean/150km²
)
)
, O
kambara
2014
.
Species
No. Individuals
Mean
Individuals
/km²
White
-
tailed Gnu
(Black Wildebeest)
994
82
.
83
0.
55
Brindled Gnu
(
Blue Wildebeest
)
281
23
.
42
0.
16
Common Duiker
7
0
.58
0.00
Eland
149
12.42
0.08
Giraffe
2
15
17.92
0.12
Greater Kudu
169
14.08
0.09
Impala
523
43.58
0.29
Klipspr
inger
2
0.17
0.00
Mountain Zebra
216
18
0.12
Oryx
680
56.67
0.38
Plains Zebra
70
5.83
0.04
Red Hartebeest
51
4.25
0.03
Sable Antelope
14
1.17
0.01
Springbuck
128
16
.64
0.07
Steenbuck
72
10.67
0.04
Warthog
92
7.67
0.05
Waterbuck
31
2.58
0.02
Total
3
,
694
307
.
83
2
.
05
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2.6
.
Discussion and conclusion
s
2.6.1. Capture and collaring
Information on leopards is difficult to obtain by visu
al observations,
so n
on
-
invasive
methods were chosen to gain ecological and biological information
. Also,
these
metho
ds
are cost
-
effe
ctive, objective and repeatable
(
Norton
-
Griffiths 1978
).
With the help of
identifying leopard signs, such as tracks and scats
,
as well as
using
camera traps
,
potential locations for box traps were identified
.
In addition, box traps were pla
ced near
waterholes
close to
mountain
ridges
,
as
leopards
prefer mountainous habitat but
need to
take in water regularly. Success of trapping the main target species, i.e. leopards, varied
among
box traps.
Only in BT03
A and BT04,
set
at
the Bergposten wate
rhole
and the lodge
waterhole
respectively,
were
leopards captured. Lack of trapping success at the other
locations
might be explained by various reasons
(see below)
. Traps BT01
,
BT01A
, BT05
and BT06
were set
at
locations
where several
signs of leopards (t
racks or camera trap
pictur
es) were detected.
GPS
data gained
via
the three leopards
collared
on Okambara
in 2013
showed that
leopards seem to revisit waterholes every 7
14 days
,
depending on the availability of
water sources
with
in the home range
and th
e time of the year, i.e. amount of rainfall
.
The
bait in the trap
s was replaced every 3
5
days
(depending on resources such as staff and
meat)
since Bailey (1993) showed in his st
udy on leopards in South Africa
that the trapping
success decreased
significa
ntly with the time bait was left in the trap
.
Therefore
,
it is
possible that o
n various
occasions leopards visited
waterholes when bait
was
older and
less attractive
.
This was already known from the p
revious expedition in 2013. H
owever,
bait availability
i
n this year
was dependent
again
on the meat resources provided by the
farm owner. The meat consumed on the farm is obtained via hunting on the premises. As
this happens
at
irregular intervals and hunting success also varies, the supply of bait meat
varied
in amounts as well as in quality. Large pieces of meat
,
which are suitable to be
attached inside or behind the trap are preferable. However, on several occasions only
small pieces of meat or intestines were available. Although these pieces of bait are idea
l
for creating scent trails towards the traps (to increase the likelihood of a predator
approaching the trap), they are only
partly suitable for baiting traps. This might have
affected the attractiveness of the baited box traps for carnivores.
BT06
was
se
t late
in
the capture season; leopard tracks were found in front of the trap, but
no animal was captured. The lack of trapping success might have been
due to the short
amount of time
the trap was set at this location. Setting a box trap
brings with it
a lo
t of
impact, e.g. cutting shrubs,
driving to the locations, etc. The trap
must
have
also
had an
intense human smell as it was handled by several people during relocation. So
the amount
of time between setting the trap and the end of the trapping season mig
ht have been too
short for animals to get
used to the n
ew feature in their surrounding
.
None
of the leopards were recaptured in the box traps
during the trapping season of this
study
. This suggests that leopards have an excellent memory of
trap location a
nd most
likely
develop an aversion to traps (getting trap shy). Interestingly, leopards living in
national parks (Bailey 1993) showed no aversion to box traps; researchers captured some
individuals up to
20
times during a study perio
d.
The trap shyness of
leopards on farmland
and the much lower trapping success compared to protected areas might be due to the
persecution of leopards on farmland.
F
armers use box traps to capture and eradicate
34
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carnivores. Therefore, selection pressure is in favour of trap shy
animals as these are
more likely to survive and produce more offspring.
Hence, the local population of leopards
consists of
increasingly
trap shy animals
. C
urious and less trap shy animals are
less likely
to survive.
No cheetahs were captured
as
the trap
s were set
specifically
for leopards and heavily
scented bait was used. Cheetah capture requires different trap positions and settings, e.g.
at marking trees or with live bait.
Blood samples taken during capture and
immobilisation
were sent to the Institu
te for Zoo
and Wildlife Research (IZW) in Berlin, Germany for further analyses. Results gleaned will
be published elsewhere, probab
ly in late 2015
or early 2016.
2.6.2. Home range
Home ranges (the area regularly used by an individual) of some carnivore s
pecies overlap
considerably among individuals, depending largely on resource density and distribution
and genetic relatedness (
Moyer et al. 2005
).
Leopards, just as other large carnivores,
cover
home ranges that
have to be of a size
large
enough
to provide
sufficient prey
availability throughout the year
.
Where prey distribution is constant
,
these territories are
often stable,
however,
under other circumstances they drift (e.g. red foxes
Doncaster
and Macdonald 1991
), move with migrating prey (e.g. wolves
Walton et al. 2001
) or are
fixed, but temporarily left by individuals to find prey (e.g. spotted hyaena
Hofer and East
1993
).
Data obtained via GPS collars from the three male leopards
collar
e
d on Okambara
showed no changes in home r
ange sizes over a
period up to nine
months from the end of
the dry season throughout the rainy season.
Since on farmland prey movements are
restricted by fences, especially on game farms with fences that keep the game
confined
with farm boundaries
, prey availability is stab
le throughout the year. Therefore leopards
are not required to migrate with prey or leave their home range to find prey.
Typically, adult male leopards require larger home ranges than females
. S
everal studies
revealed similar home range sizes within each
sex, with males
varying from 17 to 76 km²
and females ranging from 6 to 18
km²
(
Bailey 1993, Hamilton 1976, Bertrum 1982,
Mizutani
&
Jewell 1998, Stander
et al.
1997, Norton
&
Lawson 1
985, Norton & Henley
1987,
Seidensticker 1976
).
However, i
n
arid areas
t
he home range sizes of leopard
s
can
be
much larger
(
male
s
86
km², females 22
29
km²
;
Jenny 1996
)
,
and even for home
ranges of individuals of the
same sex there can be some degree of overlap
,
or
some
times
even a complete overlap,
e.g
.
if
the
whole
home rang
e of a female
is
within the home
range of a male
(
Jenny 1996,
Rabinowitz 1989, Grassman 1999
).
Most
leopard home
range data available are from studies that were conducted in protected areas (see
Appendix I: Kruger N
ational
P
ark
, Serengeti N
ational
P
ark
). I
n Namibia the sizes of MCP
(95%) varied
from
108
to
229 km
2
for males and 53
to
179 km
2
for females (see Appendix
I). A study conducted by Marker and Dickman (2005) o
n commercial farmland found 229
km² (MCP95) as home range size
for male leopards and for f
emales a range of up to 179
km
2
.
Stander et al. (1997)
estimated home ranges of male leopards varying from 210 to
1
,
164 km
², whilst
female
home ranges measured 183 to 194
km
²
in
north
-
eastern
Namibia
.
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In this study,
the home range sizes found for the mal
e leopards correlate mainly with the
study of
Marker and Dickman (2005
)
, since home range sizes
(MCP100)
f
or
L052 and
L055
were
269
km² and
173
km²
respectively
,
but
they
also
correlate
with the findings of
Stander et al. (1997
)
showing
that there can be a
high variance between different
indiv
i
duals (L051, 414
km²).
The home range of L075 was only 90 km², thus much smaller
compared to other male leopards. However, the data
only encompasses
37 days
since the
collar
appears to have failed after
this period
.
T
his is not unusual
in studies using GPS
collars as
failures and production faults happen
from time to time
.
It is interesting to note
that all of the
data
obtained was within the home range of L052. This is highly unusual as
male adult leopards defend thei
r territory against other male leopards.
Since the end of the study period, L052 has
not appeared on the camera traps again
suggesting that L075 might have taken over his territory.
However, since
L052
has
not
been
found
again
, this remains a theory
only
. L075
, on the other hand,
was shot in 2015
during
a trophy hunt on a neighbouring farm. The collar was retrieved and checked by the
manufacturer in Germany.
It emerged that
the collar was part of a faulty production line
,
which caused the failure of the c
ollar after such a short time. Failing collars are always a
setback in these types of studies. However, the report of this failure and the coincidental
retrieval of the collar allowed the manufacturer to detect the fault in manufacturing and
avoid it in fu
ture production
s
.
The fact that home range sizes on farmland are larger than in protected areas, despite th
e
stable
prey availability throughout the year, could
be
due to varying densities and
abundance of leopards in protected areas and on farmland.
Stei
n et al. (2011)
determined
a
leopard population
density of
3.6
leopards
per 100
km²
on farmland in central Namibia.
Marker and Dickman (2005
), on farmland in north
-
central Namibia, found that the average
density of leopards
on farmland
is 2.1 leopards per
100 km
2
.
O
n the current Okambara
study site, the estimated leopard density
was
1.3 individuals per 100 km
2
,
1.9 individuals
per 100km²
and 1.8
individuals per 100 km
2
in 2012,
2013
and 2014
respectively
. There
might be a high variance of leopard density ev
en within an area, depending on the habitat
and management of different farms. Some farmers sh
o
ot leopards regularly on their
premises, thus often removing the territor
y holders
and creating
space
for other
,
sometimes neighbouring
leopards to move in. Ther
efore, leopard densities
outside of
Okambara
,
on which
leopards are not persecuted,
might be lower than expected and
home ranges can be larger than in protected ar
eas where there
is
fewer
turn
over
s
within
the population.
Game
-
proof fences, in general
and i
n this study
, were not a barrier
and had
no influence on the home range
, as
all individuals
regu
larly crossed under the fence on
Okambara
.
Furthermore, prey availability might be lower on farmland compared to
protected areas. Although there is game farming
in Namibia (including Okambara), the
majority of farms
are
engaged in cattle breeding, thus only naturally abundant game
species appear on those premises. Also, the game can move between cattle farms as the
surrounding fences are purposely kept low in ord
er to allow migration of game.
Local prey
availability is therefore subject to change and can affect the home range size of leopards
.
It
has been
shown that o
verlap
often occurs
between individuals of different sex (
Arthur et
al. 1989
). In leopards, males
defend
their
territories against other
sexually mature
males,
but tolerate females, cubs and even dispersing young ma
les within their territories (
Bailey
1993, Marker and Dickman 2005
).
This is supported by the data of L074
, which show
that
her home range
is completely within the home range of L055. Usually, several female
home ranges are covered by the home range of only one male. As the home range of
36
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-
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-
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L074
is only
38 km², it is assumed that additional females roam within the territory of L055
and most lik
ely also the other male leopards.
C
amera trap pictures of female
and
juvenile
leopards taken within the home ranges of the
four
males
on Okambara support this
finding
.
2.6.3
.
Track
counts and scat collection
The largest number of tracks and scats from le
opard
s
were found close to the edge of the
small mountains in the north
east
and southwest of the study site, where there i
s also water
available (routes 3 & 6
).
Also, on route
s
1 and 9
several
signs of leopards where found;
b
oth routes include waterholes a
s well. Few signs of leopard occurrence were detec
ted on
routes 2, 4, 5, 10 and 12
. No signs of leopards were found on routes 7, 8 and 11, all of
which are situated in the plains.
This correlates
with t
he analysis of the GPS data, whi
ch
showed mountain
o
us
areas to be the preferred habitat of leopards.
Results of these non
-
invasive methods
also
show
ed
that
other
predators occur on
Okambara. Cheetahs were detected more frequently in the open areas of the study site,
where they
probably avoid
other predators
such as
leopard and brown hyaena and
because their hunting technique is more suited to open areas (
Caro 1994
).
Brown
hyaenas
occur throughout the study site as
they are looking for carcasses from other predator kills
everywhere and they patrol their
large
home range. Cheetahs are known to leave most of
their kill after having eaten their fill and do not usually return (
Caro
1994). If leopards do
not take their kill up a tree
or hide it properly
, the probability that
hyaenas
will
scavenge on
it is high.
The
re were some restrictions to these methods
.
Route
1 and
4
included
very hard, stony
surfaces and some of the routes
were in deep sand (2, 5, 6 and 8)
,
both of
which make the
detection of tracks quite difficult. Also, weather conditions such as wind and rai
n influence
the success of finding tracks; there was not much rain
fall during the study period
, but
there
were several days with
strong
wind
s
.
In addition, not all routes could be monitored
at
regular intervals, as the presence of elephants on the farm was
a highly limiting factor,
especially to the routes in the plains or some waterholes (especially Frankposten and
Bergposten). Hence, not all routes were monitored at the same frequency and intensity.
2.6.4. Camera traps
Camera
traps
are
very
useful
tools
in
wildlife research, collecting
a variety of
data
sets
and
allowing for
undisturbed
observation of species
in their habitats
to explore
their
natural
behaviour patterns
and movements,
and
to determine
population sizes
.
During the
three
months of the
stu
dy period
,
187
pictures of
most
large and medium
predator species present
in the area (leopard
, jackal, caracal, brown hyaena
, African wild
cat
and honey
badger) were recorded. Brown hyaena, honey badger
, African wild cat
and
all of
the caracal
pictures we
re
taken
during
or
after sunset.
All of these animals are mainly
active during the night; therefore detecting those species during the day is unlikely.
Jackals were recorded mostly during the night, when they are
most active,
but they can
also be seen duri
ng the periods of dusk and dawn.
Brown hyaenas and African wild cat
were detected all over the study area,
showing
the vari
ed
habitat selection within these
species. Caracal and honey badger were only detected near
ridges either at
waterholes or
along
fenc
e lines
;
apparently this is their preferred type of habitat.
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Several studies
suggest
that
leopards
are active
between sunrise and sunset
(
Nowell and
Jackson
1996,
Hamilton
1976,
Bailey
1993,
Sunquist
&
Sunquist
2002
)
. This is confirmed
by
pictures taken
o
f leopards
during this study
period
,
with leopard
s
active just before
sunset as well as
in the middle of the night
,
and
with
only a
few
records after
sunrise
,
when temperatures
are
still low
. In semi
-
arid
savannah
regions
mammals
are active at
night
to avo
id
the
heat of the day
and
associated heat
stress and energy loss
(
Bothma &
Bothma
2005
)
,
and l
eopards
usually
avoid the
heat and prefer shady
places
to
rest
(
Bothma and
l
e Riche 1984,
Walker
199
6,
Sunquist
and
Sunquist
2002
)
.
This applies to
predators as
well as herbivores.
So, the locally abundant prey species are also less active
during the
heat of the day
and
it is self
-
explanatory
that
the
activity patterns
of
leopard
prey
have an influence on
leopard hunting behaviour
. T
his
leads to an increased activ
ity of
leopards between sunset and sunr
ise
(
Bothma and
Bothma
2005,
Sunquist
&
Sunquist
2002,
Jenny and Zuberbühler
2005
)
.
Furthermore, in agricultural areas
,
where there is
also intensive persecution of predators, these species tend
to be
more active duri
ng the
night
to avoid humans.
A high percentage
(approx. 65%)
of the predator pictures wer
e of brown hyaenas and
jackals, but no individuals could be
identified. Due to their greater strength, size and
stealth, leopards are the dominant predator
s
in the s
tudy area
.
No persecution
of
predators occurs on Okambara,
so predator r
atios
should
be subject mostly to
natural
selection pressures
. In general, on Namibian farmland, the leopard is the only competitor
for brown hyaena and cheetah, and it is likely that
the latter will avoid areas where many
leopards occur. Brown hyaena
s
and leopard
s
d
o coexist in space, but they tend
to avoid
each other in time (Killian
et al.
2012). Generally, leopard
s
and brown hyaena
s
are
opportunists and better adapted to poore
r habi
tat conditions (
Estes 2012
).
Marker and
Dickman (2005), on farmland in north
-
central Namibia, found that the average density of
leopards in protected areas is 2.1
individuals
per 100 km
2
.
On this
Okambara study site,
the
esti
mated leopard density was
1.8
i
ndividuals per 100 km
2
.
In relation to the study of
Marker and Dickman (2005) and of
Stein et al.
(2011)
,
who
determined
a density of
3.6
leopards
per 100
km² on farmland in
a
central Namibia
leopard population
, this study
shows that leopard densities on f
armland are highly variable
.
Th
i
s is probably due to the
various types of habitats and the different composit
i
on of these types on each farm. In
addition, the
rate of
predator
removal
varies
among
areas/farms and can also lead to a
higher range of leopard
densities.
In addition, the density of leopards found on Okambara
is considerably lower than densities found in protected areas (see Appendix I) whilst their
home range is larger compared to protected areas. This supports the
assumption that
home range siz
e
is related to density; thus lower densities of leopards lead to larger home
ranges.
To meet the statistical assumption of the population being “closed” during the camera trap
study period
(no immigration, no emigration, no birth and no death),
a period
of 9
0 days
was selected.
The null model (M
0
) assumes that capture probability is the same for all
individuals and is not influenced by behavioural response, time or behavioural
heterogeneity among individuals. The camera trap survey produced meaningful res
ults,
but small sample sizes from
elusive carnivores appearing in low densities
makes precise
analysis difficult.
Karanth and Nichols (1998
) noted that CAPTURE performs poorly with
population sizes of 20 or fewer individuals. Therefore, the statistical ana
lyses performed
here based on just
six
recaptured individuals can only serve as an indication.
38
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-
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ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
Even with the result of a low density of leopards, overall results suggest that local
conditions are particularly favourable for different predators
such as leo
pard and brown
hyaena
. The area possesses abundant prey, good habitat features and minimal
competition,
and no persecution from humans
within the premises
.
There were some
constraints to the
camera tra
p placement design, because
traps could
not
be placed i
n the
plains area where elephants and baboons were active
and
the
likelihood of
these animals
damaging
a camera was high
.
2.6.
5
. GPS c
luster analysis
In sub
-
Saharan Africa, 92 prey species of leopard are known (
Hayward et al. 2006
). They
range from small
rodents (
Mitchell et al. 1965
) to large antelope. Bailey (1993),
Ray et al.
(200
5), Sunquist & Sunquist (2002) and others found more than 20 different prey species
in leopard scats in studies conducted mostly in national parks, where the prey spectrum is
more varied compared to game fa
rms.
So far
ten
different prey species
have been
identified for four
collared leopards
in this
study
.
The main prey species found at confirmed kill sites were greater kudu and
oryx
;
both species are highly abundant in the mo
untainous parts of the farm. Since this is the
preferred habitat of leopards, it is not surprising that they focus on the most available prey
species.
The third most consumed species was
impala
,
which occur
s
in the mountains as
well
.
On average, leopards p
refer
medium
-
sized
prey (average
23
kg
;
Hayward et al.
2006
)
;
accordingly most
prey animals
found
were juvenile
s
or young adults.
The leopards of this study had
a
kill rate of
once every
five days on average. This
correlates with
Bailey (1993)
who
estimat
es that an average 52.8 kg male leopard must
consume 3.8 kg of meat per day and an average 37.5 kg female leopard 3.0 kg per day.
The weight
s
of the
male
leopards captured on Okambara ranged from 67.5
kg to 69
.0
kg,
thus they had to consume 4.9
kg per day
and based on the average prey size of 23
kg this
would result in a kill rate of four to five days.
The female weighed
less (40 kg)
,
which is not
surprising as sexual dimorphism is common in leopards. Her kill rate was between five
to
six days and prey was
medium
-
sized. This is quite similar to the kill rates and prey size of
the male leopards and therefore at first glance surprising considering her lower body
weight. However, this female had been captured with a ten
-
month
-
old cub; as cubs at this
age are st
ill supported by their mother, it is
very likely that her usual kill rate increased due
to the increased demand for prey in order to feed herself and the cub.
No specialisation on certain prey species could be detected for any of the individuals.
2.6.
6
. Game counts
The study period for game counts was conducted in late winter and the beginning of
spring, and finished in early summer
.
On vehicle game counts, the main species observed
were oryx and
white
-
tailed
wildebeest
; the third most
detected
species
was
impala.
At
waterholes, mostly warthogs and impala were detected,
followed by
greater kudu
and
waterbuck
.
Hopcraft et al. (2005)
postulated
a
prey abundance hypothesis
,
which states that leopards
prefer to
consume prey that is most common within the h
ome range. Since oryx and
impala were some of the most observed species and were detected
via
the GPS
cluster
39
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
analysis as two of the preferred prey species, the prey abundance hypothesis is
supported
by
this study.
Furthermore, results
also corroborate
Bai
ley (1993) who cites that impala is
an important ungulate prey species of leopards throughout southern Africa, because the
species yields the greatest return of energy for that expended in locat
ing and killing it
.
High
numbers were also e
stimated for
white
-
tailed
wildebeest
. H
owever,
white
-
tailed
wildebeest
exceed the preferred prey size of leopards
,
which is most likely why this species is not part
of their diet. Also,
wildebeest
species
occur in the plains, a habitat less used by leopards.
Warthogs occur
in high numbers on Okambara
,
but are apparently not an important part of
the leopard diet.
This may be due to
the fact that
warthogs
are
spend
ing
the night
in
burrows. L
eopards are mainly nocturnal and hunt during the night or in the late evening or
early
morning hours, when the warthogs are hiding underground.
For some species the expedition data collection period coincided with their mating and
reproduction periods. For example, impala females gave birth during the data collection
period and are known to
leave their calves hidden for protection (
Skinner and Chimimba
2005
). Suckling juveniles
rest in undergrowth and
do not need to go to waterholes during
the first weeks of lif
e.
D
ense
vegetation
over large distances
may have
reduced
the
visibility of and
therefore
sample size
for
some
species.
To account for this, game counts should
be
repeated
regularly throughout the year. Observers
at waterhole
s
rarely
disturb
ed
the animals
visiting. Anim
als were alert, but not fleeing, thus providing possibilities
to c
ollect data. The
data collected during the expedition should form the baseline for further data collection,
which should include
data collection during dry a
nd wet seasons. Data collected over
different
seasons
could provide important information
for farm
management
regarding
population growth.
2.6.7
.
Conclusion
s
The expedition’s r
esearch
has shown that different carnivore species coexist
on
Okambara
. Species included leopard, brown hyaena, cheetah,
African wild cat, honey
badger,
caracal and black
-
backed
jackal. The habitat
types in relation to the prey
abundance present seem to be
suitable for
populations
of the different carnivore speci
es
and their reproduction
,
if no other threats such as persecution or trophy hunting of
predators arise.
The
Okambara
study site is surrounded by livestock farms, primarily
with
cattle.
Using
camera trap pictures, several leopard i
ndividuals could be
identified
,
and based on the
GPS
data gained so far it is very likely that most of the home ranges of these animals
exceed
the Okambara game fence line
(see Figure 2.5.2a)
.
Communication with
neighbouring farmers should continue
s
o
that emerging problems such as leopard attacks
on cattle can be recorded and discussed and non
-
lethal solutions can be found.
Already,
one kill of
a cattle calf has
occurred (predated by L051) on a neighbouring farm.
As
this
project openly shares data, experiences and advice with farmers
, the owner of this
particular farm
has pledged
that there will be no persecution of leopards on his premises if
lo
sses of cattle stay low. This shows the importance of stakeholder involvement in this kind
of project, as farm owners are increasingly interested in learning more about t
he ecology
of predators and how to preserve them whilst also protecting their liveliho
ods.
40
© Biosphere Expeditions,
an international not
-
for
-
profit
conservation
or
ganisation registered in England, Germany, France, Australia and the USA
O
fficially accredited member of the United Nations Environment Programme's Governing Council & Global Ministerial Environment Forum
Officially accredited member of the International U
nion for the Conservation of Nature
The results presented here provide information to assist wildlife managers and
conservation bodies on predator carrying
capacity and predator
prey interactions.
Understanding the human
carnivore relationship is central to rural and commercial
carnivo
re conservation and management and ultimately to the possibility of sustainable
coexistence.
We hope that science
-
based results such as the ones presented here,
translated
into
readily understandable management advice, will promote coexistence of stakehol
der
farmers and predators by reducing conflict and pointing towards revenue streams such as
ecotourism. Biosphere Expeditions itself working on a Namibian game farm with
international volunteers is a showcase of the oft
-
quoted win
-
win situation. Income for
the
farm through low
-
impact ecotourism helped provide useful scientific results that translated
into sound management advice and predator/biodiversity conservation.
In the end, successful management of carnivores will require modifying both human and
wil
dlife behaviour. Long
-
term success can only be attained by changing human behaviour,
especially people’s attitudes towards, and tolerance of, human
predator conflict situations.
Management recommendations for stakeholder farmers
On game farms
,
game speci
es are prevented from migrating by fences and have to adapt
to farm conditions. Therefore good farm management is required to maintain stocks of
healthy game animals
, especially if an extreme drought
occurs
. With good management,
fenced areas can be very g
ood conservation tools, for rare species in particular
.
T
o pr
otect valuable game species
from leopard depredation, farm managers should
ensure that
t
heir farm
is
well
stocked
with low
-
value
spe
cies (less expensive than sable
and roan antelopes), particula
rly impala
and springbok
.
Leopards are likely to then
concentrate on
these
preferred easy target species and stay away from larger, more
valuable
species.
Managers should also ensure
that the entire
game population is in
a
good, healthy condition
and
that
the fenced
areas are
not overgrazed
resulting in
weaken
ed game
animals,
therefore creating easy prey for predators.
Outlook
and recommendations for further work
To develop effective conflict resolution strategies
,
more about
leopard biology on game
farms
must be known
.
Okambara
is surrounded by cattle farms,
which have been
i
ncluded
in the GPS
cluster analysis
. Game counts and camera trap
surveys should also take place
on neighbouring farms
to gain more information about prey availability and density of
l
eopards.
Capturing and collaring of further predators
, especially