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Posts Tagged ‘big cats’

White stripes on black or black stripes on white? Although our perceptions may differ, we can all agree that the zebra has one of the most striking coats seen in the animal kingdom.

Two species of zebra occur in southern Africa: Burchell’s (or plains) zebra Equus burchellii and mountain zebra Equus zebra. Both Burchell’s zebra and the mountain zebra sub-species, Hartmann’s mountain zebra Equus zebra hartmannae, which is listed as vulnerable on the IUCN Red List of Threatened Species, are found in Namibia. (The Cape mountain zebra is restricted to reserves in South Africa.)

Although zebras’ pied colouring serves to camouflage Hartmann’s zebra in mountainous areas, it often seems to be clearly visible in grassland, accentuated against the tawny shades of the antelope species, posing the question as to the evolutionary purpose for zebra stripes. Many hypotheses have been voiced over the years. One of the more naive explanations we receive as children simply describes zebras as horses wearing pyjamas, while the African legends have a tale about Zebra falling into the fire while challenging Baboon, burning the well-known stripes onto his skin.

Stripes merge individuals to a group.  Photo: Ron Swilling

Stripes merge individuals to a group. Photo: Ron Swilling

It has been suggested, however, by those with more of a scientific bent that zebra stripes have a more practical and life-affirming purpose, to deter predators. Stripes merge when seen from a distance, making it more difficult for a predator to distinguish a single animal from the group, a definite advantage for herd animals. Because predators will always try and single out an individual animal, zebras’ safety depends on tight bunching. This trait can be seen in breeding groups when the mares and foals keep to the front and the stallion takes the rear.

Stripes may also serve to confuse a predator as they narrow towards the head, neck and shoulders, widen towards the rump and break the outline of the animal, presenting a distorted image, making it difficult for the predator to judge the size, distance and direction the zebra is moving. The stripes also enable zebras to follow one another at night in poor visibility and amidst dust thrown up by their hooves when the big cats are out on the prowl.

Zebras are preyed upon by lion, leopard, cheetah, hyaena and wild dog, animals that hunt using different methods and at different times of the day and night, making overall protection important at all times.

Experiments reveal that zebras are attracted to stripes, finding them visually stimulating, another mechanism programmed into their genes to ensure the herd animals remain together. Some scientists also believe that because colours absorb or reflect heat at different rates, black and white stripes may create a convection current, keeping them cool.

Zebras (10 Cent), issued in 1983, artist: Jacobus Johannes 'Koos' van Ellinckhuijzen

Zebras (10 Cent), issued in 1983, artist: Jacobus Johannes 'Koos' van Ellinckhuijzen

An interesting evolutionary hypothesis suggests that the zebra developed stripes over time to allow it safe passage down the African continent through tsetse fly areas. Stripes deter the blood-sucking pest that targets large surfaces. This may explain why the predecessors of the zebra managed to survive in Africa unlike those of other Equus groups. (Domesticated horses were introduced much later by the early settlers.)

In the wild, survival tactics take all forms and shapes and animals have perfected methods to ensure their survival. If solitary, camouflage, stealth and silence provide protection, and if sociable, safety is often found in numbers. In addition, some animals have built-in weapons such as horns, and others, like zebras, depend on their colouration and patterning – their dazzling black and white pyjamas – to baffle the enemy.

Contact for collectors: Philately Services, Private Bag 13336, Windhoek; Tel +264 (0)61 2013097/99, philately@nampost.com.na

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Beauty and power blend seamlessly in Panthera pardus, an animal that seems to have been given a double share of both. As the leopard emerges from a thicket, blending into the dappled light and pads across the leafy earth to disappear once again into the vegetation, the observer cannot help the quickness of breath or the feeling of awe he experiences for this fleeting vision of the ‘prince of stealth’.

Solitary and predominantly nocturnal, the elusive leopard (luiperd in Afrikaans) is rarely seen. Once having a wide distribution including Africa and the Arabian Peninsula through south-western Asia into India, China and the Russian Far East, the leopard’s range has shrunk considerably over the years through hunting, persecution in farming areas and loss of habitat. It is listed as near-threatened on the IUCN (International Union for Conservation of Nature and Natural Resources) Red List. Although it has disappeared from 36.7 percent of its historical range in Africa, is on the verge of extinction in North Africa and survives only in fragmented populations in some parts of its range, it is still widespread in sub-Saharan Africa, managing to endure in areas where many of the large cats have not.

Panthera pardus, issued in 1998, artist: Sheila Nowers

Panthera pardus, issued in 1998, artist: Sheila Nowers

There are nine sub-species of Panthera pardus worldwide recognised by the IUCN, living in a wide range of habitats from rainforest to desert, where there is sufficient cover for concealment. The leopard is not dependent on water, obtaining moisture from the body fluids of its prey, but will readily drink if water is available. In Namibia, it is found throughout the country but prefers areas with rocky outcrops and mountains. It marks its territory using scratching posts and urine spray.

The smaller of the Panthera ‘big cats’, the leopard, with its rosette markings, relatively short muscular limbs, a long low-slung body and large skull with powerful jaws, is an opportunist feeder. Its diet includes anything from dung beetles, dassies, francolins, carrion and black-backed jackal to medium-sized and occasionally large antelope. It has even been known on the rare occasion to feed on crocodile. Secretive, well-camouflaged and silent, it hunts by stealth, stalking its prey with patience until close enough to pounce, taking it by surprise. To protect its kill from other predators, the leopard carries it up into a tree, or drags it amongst rocks or under dense bush. In areas where its natural prey has been eradicated, it may prey on domestic stock and has proven to be a menace in farming areas.

Rare sight: Leopard killing a crocodile.  Photo: Hal Brindley

Rare sight: Leopard killing a crocodile. Photo: Hal Brindley

Leopards unite to court and mate and litters of 2-3 cubs are born after a gestation period of 100 days. The female hides the 500 g cubs in dense cover or rock crevices, out of danger. The cubs stay with their mother for 18 months, learning to hunt and fend for themselves. While on the move, they follow the white tip on her tail which serves as a beacon.

Half the size of a lion, the adult leopard standing at 80 cm is a formidable 50-90 kg powerhouse not to be trifled with. (The male is larger than the female with a heavier thick-set head.) Usually shy, however, and sensitive to noise, it will quickly disappear when there is a disturbance. It is only known to attack humans when trapped, threatened or injured, preferring the flight rather than the fight response to danger.

Rare sight: Leopard killing a crocodile.  Photo: Hal Brindley

Rare sight: Leopard killing a crocodile. Photo: Hal Brindley

Its low rasping and rhythmic grunt-like call, likened to the sawing of wood, alerts Etosha visitors to its presence at a waterhole before it makes its rare appearance from out of the darkness. In areas where there is little human disturbance it can sometimes be seen in the cooler hours of the day padding along a dry river course or through the long grass, offering a fleeting opportunity to witness ‘the embodiment of feline beauty, power and stealth’.

Contact for collectors: Philately Services, Private Bag 13336, Windhoek; Tel +264 (0)61 2013097/99, philately@nampost.com.na

 

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