Electronic Supplementary Material
Detailed methods
Study area
The study took place between September and May (austral summer), within the TUSK Trust
Cheetah Rehabilitation Camp (4000 ha) of the AfriCat Foundation, on the guest farm Okonjima
(20º50’S 16º38’E), 200 km north of Windhoek in central Namibia, a location which wild cheetah
currently inhabit. This summer rainfall region forms the western border of the Kalahari and
consists predominantly of shrubland and thornbush savanna. Potential prey species common in
the camp included hares, dik-dik (Madoqua kirkii), steenbok (Raphicerus campestris), impala
(Aepyceros melampus) warthog (Phacochoerus aethiopicus), red hartebeest (Alcelaphus
buselaphus), kudu (Tragelaphus strepsiceros), gemsbok (Oryx gazelle) blue wildebeest
(Connochaetes taurinus), zebra (Equus equus) and giraffe (Giraffa camelopardalis). Intraguild
predators included two resident leopards (Panthera pardus) with their cubs.
Animals
Two female and four male wild born cheetah (Acinonyx jubatus) which became habituated
during a “rehabilitation programme” were allocated to the study. Two male cheetah had previous
hunting experience. Four siblings (two males and two females) had not previously hunted on
their own but after release they remained together as a successful hunting coalition, although the
females were observed hunting independently on occasion. All procedures were approved by the
Animal Ethics Screening Committee of the University of the Witwatersrand (protocol no.
2005/42/4).
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Weather data measurements
We collected weather data at the field site by erecting a portable weather station (Hobo Weather
Station, Onset Computer Corporation, Pocasset, USA) in an open area that was not shaded or
protected by vegetation. We recorded dry-bulb temperature (°C), relative humidity (%), wind
speed (m.s-1), solar radiation (W.m-2) and standard (150 mm diameter) black globe temperature
(°C), at a height of 1 m, at 30-min intervals. Over the study period, daily maximum air
temperature averaged 29.8 ± 4.0°C (with a range of 17.1°C to 38.8°C) and daily minimum air
temperature averaged 12.8 ± 4.7°C (range –2.0°C to 20.6°C). High solar radiation (maximum
daily radiation 1026 ± 183W.m-2) resulted in daily black globe temperatures ranging between
11.4 ± 5.1°C and 44.2 ± 5.5°C. Relative humidity averaged 61 ± 30% and wind speed averaged
1.0 ± 0.4 m.s-1 over the study period.
Temperature and activity data loggers
Under sterile surgical conditions, we implanted temperature-sensitive and movement-sensitive
data loggers. The temperature logger (mlog_T1A, Sigma Delta Technologies Pty Ltd, Perth,
Australia, resolution 0.06ºC, calibrated accuracy better than 0.1ºC, ~25 x 25 x 10 mm, mass of
~10 g when covered in wax), which recorded body temperature every minute, was tethered in the
abdominal cavity via an incision in the linea alba. An additional incision was made on the upper
hind limb, where an activity logger was tethered subcutaneously. The activity logger (Actical,
Mini-Mitter Corporation, Bend, USA, ~40 x 40 x 15 mm, mass of ~40 g when covered in wax)
recorded activity over successive 5 min intervals. The activity logger recorded movement via a
multidirectional, piezoelectric accelerometer, which was sensitive to 0.05 G. Activity loggers
were orientated so that the axis with optimal sensitivity was parallel to the body axis, such that
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the main sensitivity of the logger was to body movement horizontal to the ground. All data
loggers were covered in an inert wax (Sasol EXP986, Johannesburg, South Africa) and drysterilized in formaldehyde vapour before implantation.
A neck collar (African Wildlife Tracking, Pretoria, South Africa) with a tracking radio
transmitter also was fitted to each cheetah. The cheetah were maintained in captivity for two
weeks, and then released into the rehabilitation area where they were free to conduct their own
lifestyle, including hunting naturally. The four siblings, which had no previous hunting
experience before being released into the camp, were supplementarily fed twice during the first
month. Thereafter, cheetah hunted for themselves. We measured temperature and activity for
seven months, after which we recovered and downloaded the data loggers. For most of that
period, there were no humans in the cheetahs’ vicinity. We periodically tracked the cheetah by
vehicle and on foot, keeping them just in visible range. Our presence did not prevent them
hunting [3]. We identified successful hunts mostly by finding cheetah on fresh kills, but also
directly observed five successful hunts and 23 unsuccessful hunts. We correlated hunt behaviour
with activity and body temperature recorded on the data loggers.
Data analysis
Our male cheetah (M4) developed gastritis a month after release and was returned to captivity
for treatment. He was killed by a resident leopard shortly after he was re-released. Another male
cheetah (M3) was killed by a leopard, less than two months after release. Both these cheetah
therefore were excluded from the analyses, except that some of M3’s data are included in Fig. 2
for comparative purposes. A third male cheetah’s (M1) activity logger was removed 60 days
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after surgery after an injury occurred which caused it to break through the skin. We analyzed
body temperature and activity for 12 ± 3 (mean ± SD) successful and 6 ± 2 unsuccessful hunts
per cheetah for four cheetah (M1, M2, F1, F2). To compensate for inherent differences in
sensitivity between movement-sensitive loggers, activity was expressed as a percentage of the
maximum recorded for that logger.
We used a series of generalized linear mixed models (GLMMs) with Gaussian error and identity
link to investigate the effect that success of the hunt had on the cheetah’s body temperature
profile in terms of body temperature at the time of maximum activity, maximum body
temperature reached, body temperature increase and the area under the temperature increase/time
curve, following 63 hunts. Here, we entered maximum activity during the hunt, duration of the
hunt, air temperature and time of day when the hunt occurred as ‘control variables’ because of
their potential impact on the cheetah’s body temperature profile. Because prey size influenced
hunting success of Serengeti cheetah [4], we investigated the effect of prey mass on the body
temperature increase following successful hunts. Prey mass was estimated based on the body
mass of prey species taken by cheetah in South Africa [16]. We used a series of GLMMs to
investigate the effect of prey mass, maximum activity during the hunt, duration of the hunt, time
of day and air temperature when the hunt occurred on the body temperature profile in terms of
maximum body temperature reached, body temperature increase, rate of body temperature
change and the area under the temperature increase/time curve, following 40 successful hunts. In
all GLMMs we entered individual cheetah as a random factor to control for the nonindependence of data points allowing each hunt to be entered as a single data point [17]. All
GLMMs were performed in STATA v12 software (StataCorp, College Station, USA).
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References:
3.
Mills M. G. L., Broomhall L. S. & du Toit J. T. 2004 Cheetah Acinonyx jubatus feeding
ecology in the Kruger National Park and a comparison across African savanna habitats: is the
cheetah only a successful hunter on open grassland plains? Wildl. Biol. 10, 177-186.
4.
Hilborn A., Pettorelli N., Orme C. D. L. & Durant S. M. 2012 Stalk and chase: how hunt
stages affect hunting success in Serengeti cheetah. Anim. Behav. 84, 701-706.
16.
Radloff F. G. T. & Du Toit J. T. 2004 Large predators and their prey in a southern
African savanna: a predator's size determines its prey size range. J. Anim. Ecol. 73, 410-423.
17.
Pinheiro J. C. & Bates D. M. 2000 Mixed effects models in sand S-PLUS. 1 ed. New
York: Springer-Verlag.
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Table S1. Body temperature parameters (mean ± SD) for four cheetah (two males and two
females) over 178 days (mean 24-h air temperature averaged 20 ± 4ºC with a minimum of 13 ±
5ºC and a maximum of 30 ± 4ºC), together with the body temperature and activity profile
following unsuccessful and successful hunts.
M1
M2
F1
F2
Average
38.3 ± 0.3
37.3 ± 0.4
39.3 ± 0.5
2.1 ± 0.6
38.0 ± 0.2
37.0 ± 0.4
39.2 ± 0.6
2.2 ± 0.7
38.5 ± 0.3
37.4 ± 0.4
39.7 ± 0.6
2.3 ± 0.7
38.3 ± 0.2
37.3 ± 0.5
39.6 ± 0.6
2.4 ± 0.8
38.3 ± 0.2
37.3 ± 0.2
39.5 ± 0.2
2.3 ± 0.1
Body temperature at time the chase was
terminated (ºC)
Unsuccessful hunt
Successful hunt
38.5 ± 0.5
38.1 ± 0.3
38.1 ± 0.5
38.3 ± 0.5
38.3 ± 0.5
38.5 ± 0.5
38.1 ± 0.7
38.5 ± 0.4
38.3 ± 0.2
38.4 ± 0.2
Maximum body temperature reached (ºC)
Unsuccessful hunt
Successful hunt
38.9 ± 0.5
39.3 ± 0.6
38.4 ± 0.5
39.0 ± 0.6
38.7 ± 0.4
39.2 ± 0.5
38.6 ± 0.6
39.4 ± 0.7
38.7 ± 0.2
39.2 ± 0.2
Maximum body temperature increase (ºC)
Unsuccessful hunt
Successful hunt
0.7 ± 0.3
1.5 ± 0.6
0.5 ± 0.3
1.1 ± 0.7
0.4 ± 0.2
1.3 ± 0.8
0.6 ± 0.2
1.3 ± 0.7
0.5 ± 0.1
1.3 ± 0.2
Area under the temperature increase/time
curve (ºC.min)
Unsuccessful hunt
Successful hunt
18 ± 22
89 ± 48
14 ± 14
94 ± 50
1±9
51 ± 46
3 ± 12
79 ± 61
9±8
78 ± 19
Time to maximum body temperature after
chase had ceased (min)
Unsuccessful hunt
Successful hunt
13 ± 5
68 ± 44
12 ± 6
39 ± 33
16 ± 5
38 ± 24
10 ± 6
29 ± 10
13 ± 3
44 ± 17
Maximum hunt activity (% maximum)
Unsuccessful hunt
Successful hunt
44 ± 18
60 ± 23
53 ± 27
59 ± 18
45 ± 25
68 ± 28
57 ± 30
58 ± 25
50 ± 6
61 ± 5
31.2 ± 5.5
26.3 ± 5.1
28.5 ± 4.6
21.5 ± 5.9
30.0 ± 4.5
21.4 ± 7.8
28.3 ± 5.1
22.2 ± 5.8
29.5
22.9
24-h body temperature (ºC)
Mean
Minimum
Maximum
Amplitude of rhythm
Air temperature at time of hunt (°C)
Unsuccessful hunt
Successful hunt
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