Words Willie Olivier
The leopard is a shy, solitary creature which is mainly active at night and less vocal than lions, which makes it extremely difficult to follow and study this elusive cat.
Having spent the last 19 years studying the ecology and behaviour of leopards in the south of the Kalahari Gemsbok National Park, which forms part of the Kgalagadi Transfrontier Park, it is probably no exaggeration to say that no one knows this predator better than Professor Koos Bothma.
Professor Bothma recently gave a fascinating insight into the ecology and behaviour of the leopard when he gave a presentation at the Namibia Scientific Society in Windhoek.
Bothma and his San trackers logged 2,608km of leopard tracks that were followed over 185 days during study visits of about two weeks between January 1976 and September 1994. During this period, Bothma built up an extensive database of every aspect of the leopards of the southern Kalahari.
Among his findings is that the leopards of the southern Kalahari use the most extensive ranges in the world, compared to leopards occurring elsewhere. Adult male leopards in the southern Kalahari have a mean range of nearly 2,105km² compared to savanna areas with a high density of prey such as the Kruger National Park where leopards have a mean range of just 25km².
Another interesting finding is that unlike elsewhere, the ranges of male and female leopards in the southern Kalahari overlap, but they usually do not occur in the same place at the same time. Distances between individuals are maintained through vocalisation and the use of scent-marking through spray-urination and tree clawing.
Bothma’s research found that the Kalahari leopards are independent of surface water. The maximum distance a leopard was tracked between successive drinks of water was just short of 159km. Water is obtained from the body fluids, especially the blood of prey, while metabolic water, a by-product of respiration through oxidative metabolism of food, can produce between 5% and 10% of the leopard’s total water requirement. Tsamma melons, Gemsbok cucumbers and Wild cucumbers, which consists of 90% of water, are also eaten.
Bothma’s research has shown that the southern Kalahari leopards are opportunistic feeders and prey type is not essential. The Black-backed Jackal is a favourite food source of the leopards and the easiest prey with a mean of 2.7 hunts per kill. Despite their formidable armour of quills, porcupines are also caught by flipping them upside down to get to the soft underparts.
Another observation made by Bothma is that the Kalahari leopards do not drag their catches into trees as leopards do in the Kruger National Park, but usually drag them to the shade of nearby trees. He ascribed this to the low density of spotted hyaenas in the southern Kalahari.
Cub mortality of the southern Kalahari leopards is a staggering 90% or more. Starvation, when the mothers don’t hunt successfully and cannot return to the cubs regularly for suckling, and predation by other carnivores are two common causes of cub mortality. Females come into oestrus again when cubs die, and during the lifetime of a female, she will replace herself and an adult male through the surviving cubs.
Bothma estimates that the Kgalagadi Transfrontier Park, which covers an area of 37,991km², has an adult leopard population of 171, but the population could be more significant because his study was done in the arid southwestern part of the park. Research by large carnivore biologist Dr Paul Funston has shown that there are 4.5% more leopard tracks in the northeastern part – which has a higher rainfall and consequently a higher prey density.
WRITTEN IN THE SAND
Professor Bothma, an internationally acclaimed wildlife management specialist and co-author of Game Ranch Management which is now in its sixth edition, has authored over 100 scientific papers and reports.
His book, Written in the Sand, was launched in Windhoek on the same occasion. Written in the Sand is an entertaining but insightful read filled with numerous anecdotes, reflections and anxious moments Bothma spent in the Kalahari over several decades. In addition to sharing stories about his introduction to the southern Kalahari way back in December 1962, the book covers aspects such as facts and myths about the southern Kalahari, the southern Kalahari ecosystem, the Kalahari San and the conservation and early research of the southern Kalahari. Bothma also tells the story of his early personal research and provides a fascinating insight into the life of the southern Kalahari’s second largest predator.
Professor Bothma’s visit to Namibia was sponsored by Point Break, Pumping Solutions and Mount Etjo Safari Lodge, while Tony Edmunds (Point Break), Heiko Denker (Pumping Solutions) and Waltraud Fritzsche of the Namibia Scientific Society made the arrangements for his visit.