Seeing a leopard in the wilds tops the list of most people heading into the wilderness. It is a secretive, solitary and mainly nocturnal cat – factors which make it extremely difficult to see.
Count yourself lucky then if you do chance upon a leopard when visiting the Kalahari Gemsbok National Park. Internationally renowned wildlife management specialist Professor Koos Bothma has studied the leopards of the southern Kalahari for 19 years.
He estimates that there are about 35 leopards in the Kalahari Gemsbok Park – one leopard in nearly 300km². This is not surprising as the southern Kalahari leopards have the largest range in the world for its kind. Adult males have a mean range of 2,104km², while females have a mean range of 1,258km². By comparison, in the Kruger National Park which has high prey density the mean range is a mere 25km².
During his research on leopards, Professor Bothma, who was assisted by San trackers, followed 2,608km of leopard tracks on foot and by vehicle during two-week study trips between January 1976 and September 1994. Information was also collected by fitting satellite and radio tracking collars to leopards.
One of the fascinating findings is that the southern Kalahari leopards are independent of water. The maximum distance between successive drinks was just under 159km, while the maximum interval between drinks was ten days. Water is obtained from the body fluids of their prey, especially the blood, as a by-product of their metabolic processes (5% to 10% of their total water requirements) and by eating Tsamma melons, Gemsbok Cucumbers and Wild Cucumbers which consist mainly of water.
Satellite tracking enabled Professor Bothma to establish that male and female leopards have core areas of 981km² and 239km² and that there are considerable overlaps in their overall ranges, as well as in their core areas. In the case of males the overlaps in core areas range from 15% to 61%. The leopards, however, never occur in the same areas at the same time.
In a harsh environment like the Kalahari it is not surprising that cub mortality is high, but it does come as a shock that it is 90% or more. Starvation when their mothers are unsuccessful at hunting and cannot return for suckling, predation by other carnivores and injury or death of female leopards with cubs are among the main causes of cub mortality. Females have a lifespan of between ten and 12 years and come into oestrus again when their cubs die. Taking this into consideration, Professor Bothma says during her lifetime, a female would be able to replace herself and an adult male through her surviving cubs.
The leopard is an opportunistic feeder which will hunt any potential prey animal. Males and females have success rates of 11% and 10% when stalking prey and 15% and 28% when chasing their prey. Females with cubs, however, have a higher success rate because they move shorter distances between kills and hunt more small and easy to kill prey – which increases cub survival. Professor Bothma’s research found that the Black-backed Jackal is the easiest prey to hunt with 2.7 hunts per kill, while one in three hunts of porcupines is successful – despite their formidable armour of quills.
Professor Bothma’s research has provided a rare and fascinating insight into these secretive cats. He is the author of more than 100 scientific papers and reports, but these publications are inevitably aimed at the scientific community.
Fortunately, though, he has published a book, Written in the Sand, which was recently launched in Windhoek. Although only one chapter deals with his leopard research, it is an absorbing book which tells the story of when he began studying the large herbivores of the southern Kalahari way back in 1970 before turning his attention to leopards, the origin and ecology of the southern Kalahari, its conservation history and the Kalahari San people.
It tells stories of the hardships faced by the wildlife of the Kalahari and the challenges researchers face when venturing into this harsh land. It tells the stories of close encounters with leopards, getting lost in the dunes and getting bogged down in mud. The wealth of information is interspersed with anecdotes, memorable moments and lessons learnt – such as that a leopard never attacked Professor Bothma’s vehicle when the front did not face the animal.
The book is available at the Book Den in Windhoek. Price N$595.00 (inclusive of VAT).
Author: Willie Olivier