The Lions of Intu Afrika Kalahari Game Reserve

The Kalahari Desert is the largest continuous mantle of sand in the world, stretching across some nine countries and covering over 800 000 km. The African lion is endemic to the Kalahari and manages to survive in an ecosystem characterized as a semi-desert. These lions are of the toughest in the world, facing regular and rigorous drought cycles, veld fires and temperatures exceeding 40ºC in summer and reaching -15ºC in winter. They are generally smaller than their counterparts in eastern South Africa with males averaging between 180 and 200 kg and females around 120 kg. They survive on small mammals such as the porcupine and even hunt bat-eared fox to survive. Oryx comprise about 40 % of their diet and springbok about 10 %. All lions are independent of drinking water and as a result, this does not really influence them. Due to the vast areas they must cover to survive, Kalahari lions will walk up to 60 km in one stretch to find food.

The prides are smaller and generally these split up when they hunt. Whereas prides of up to 18 females and three to four males will be found in the lowveld and areas such as Kenya, the Kalahari prides will consist of maximum six females and two males. Cub mortality is very high. The cause of death is usually starvation due to the large distances that females must cover to hunt and find food so as to produce milk. They can be absent from their cubs for up to five days. In a study done by Fritz Eloff over a period of two years, only two cubs in the entire Kgalagadi Transfrontier Park survived past the age of two years.

Kalahari lions prefer the well-known shepherd’s tree. These trees are generally referred to the lions’ nursery, lounge, playroom and bedroom. The males are generally black-maned although blonde males also occur. Kalahari lions also retain their spots on their lower legs and bellies and may be darker on the rump and back.

Intu Afrika is home to three Kalahari lions. Currently there is an adult male and two adult females. The lions were sourced from Harnas Lion, Leopard and Cheetah Farm in the Gobabis district in eastern Namibia late in 2000. The female and one of the males are siblings and were born early in 2000. The older male was a nomad that came into Namibia from Botswana. He is estimated to have been born during mid-1999. The animals were held in captive conditions and fed pieces of meat on a daily basis. Subsequent to their arrival on Intu Afrika they were released into a 500 ha enclosure with the aim of rehabilitating them with eventual release onto the 10 000 ha reserve.

Research on their capacity to avoid heat stress and use of certain behaviors to do so is being performed on these lions by the Zoology department of the University of the Free State in South Africa. Fieldwork was performed during winter 2003 and summer 2004. The lions were darted and Thermocron buttons that measure surface temperature were implanted in the large male and the female at the neck, base of the tail and in the loins. This was required since lions, like all mammals, can regulate their core temperature in their bodies but surface temperature fluctuates.

Preliminary results indicate that lions are exceptionally adept at tolerating cold and heat. Published literature states that lions are most active under 10ºC and the fact that lions are successful in the Kalahari indicate their ability to tolerate extreme temperatures. Lions, as all cats and dogs, can only sweat through the paws and the mucous membranes of the mouth. This is why one regularly sees lions lying with their forepaws upturned. They also use panting to cool down the core temperature of the body and have a special structure that uses panting to cool down the blood going into the brain. The data from the buttons indicates that surface temperature can increase up to 3ºC when they pant. Maximum number of pants recorded in a minute was 190!

When lions lie with their loins exposed, they are using evaporation to cool down. The majority of times they will lie parallel or perpendicular to the wind, holding their legs in such a way to maximize the effect of the wind. Surface temperature decreases by up to 4ºC. Drinking has the same effect but for some reason, the lioness’s body responds within an hour and the male only within two hours. Reasons for this are not known although the weight of the male at 226 versus that of the female at 126 may play a role. The male is somewhat overweight while the female’s condition is perfect.

During the winter trials, the mane of the male did not show any effect on neck temperature when compared to that of the female. Also, male lions are notoriously absent from the pride and as a result, the large male generally slept a little away from the female. His surface temperature therefore varied greatly with the female’s staying more constant since she was generally always in the company of her brother.

The summer trials are currently underway but observations indicate that thus far, when the temperature increases to above 35ºC, the lions simply use panting. It appears that all other activities such as grooming, lying with the loins exposed and so forth, are sacrificed for dissipating body heat to the environment.

It is said that lions will lie like “honey in the sun” during the day. When they do this they are not lazy, they are in fact, controlling their body temperature!