Nestled inside a mountain wilderness, at the transition between the Little and Great Karoo, lies Bosch Luys Kloof. The animals that call this valley and surrounding mountains home are equipped with a series of adaptations which allow them to survive and thrive amidst drought conditions, temperature extremes, steep and rocky terrain and thorn-bearing plants, to name just a few.
This majestic spiral-horned antelope occurs naturally at Bosch Luys Kloof. Excellent jumpers, they can clear a 2m-high fence with relative ease, which allows them to move quite freely to access food and water. It’s this ability to roam that has earned them the nickname ‘Trek Kudu’ by local farmers, as they make their way through farms in the area, especially during the winter months, when the thorn trees lose many of their leaves and are not as palatable, forcing the Kudu to move to greener pastures.
Kudu have excellent camouflage when hiding in thickets, earning them another nickname: ‘Grey Ghosts’. They are almost exclusively browsers, showing preference towards Acacia trees and in the Bosch Luys Kloof area their calving season often coincides with the Sweet thorn (Acacia karroo) bearing its protein-rich seedpods.
Peak calving occurs around February and March, but can begin as early as November, following an eight-month gestation period. The bulls don’t walk with the cows all year, but rather form small bachelor herds or walk alone. During the breeding season however, typically autumn through early winter, the bachelor groups will split up and bulls will join small family groups of cows to mate with them.
The Cape Mountain Leopard is the main and likely only predator of Kudu at Bosch Luys Kloof and typically targets calves and younger animals, although they are able to take down larger animals as well. Sadly, Kudu fall prey mostly to hunters as they traverse privately-owned land during their localised migrations.
Translated from Afrikaans, Klipspringer means ‘rock jumper,’ accurately describing one of the things this antelope is best known for. Their blunt-tipped hooves give them traction when jumping from rock to rock and scaling steep gradients, and their unique gait, with legs often pressed against each other when stationary, allows them to balance on small surface areas. This adaptation also allows the Klipspringer to change direction suddenly, to avoid predators, which often also elicits a loud whistling alarm call through the nose, that can be heard up to 700m away.
Klipspringer have a coat made up of hollow fibre hairs which are able to trap air, allowing them to survive the cold and windy conditions associated with high elevation, and also assist in the reflection of radiant heat on hot Karoo days. These hair fibres also help to cushion the blow should they lose their footing and take an unlikely fall. The golden colour of their coat has a rough appearance and can differ, depending on the terrain, allowing them to easily blend into their rocky environments.
Primarily browsers, their diet is made up of a variety of plants – including Euphorbia species, which are toxic to many animals – fruits, flowers and lichen. They also have the ability to gain nutrients missing from their diet, such as phosphorous and calcium, by chewing bones (known as osteophagia) and soil from termite mounds (known as geophagia). They can obtain all of their moisture requirements from the plants which form part of their diet, making them independent of water and in its absence they will survive. As with most animals, however, if water is available they will drink it.
Klipspringer will generally mate for life. Ewes are typically slightly larger than rams, and only the rams have horns. One lamb is born, most often in the spring or summer months, after a gestation period of six months. After a period of a year, the youngster will be evicted from the family to avoid inbreeding. They are mostly crepuscular (or active in twilight), and can often be seen resting during the heat of the day on the Bosch Luys Kloof pass.
The Cape Leopard deserves a mention for many reasons. Panthera pardus or the leopard has the most extensive range of any cat (except the domestic cat), occurring across Africa and the Arabian Peninsula, through Asia to eastern Russia and Korea. There are several sub-species of leopard throughout the globe, but Panthera pardus pardus, the Cape Mountain Leopard, is still considered the same species as leopards found in the savannah and bushveld of southern Africa, despite noticeable differences in appearance, diet and habit.
Cape Leopard males weigh, on average, around 35kg (compared to savannah males which weigh from 60-70kg), and females in the Cape around 20kg (savannah females from 35-40kg). The leopards of the Western Cape mountains are incredibly shy and elusive, and have far larger home ranges than those further north. A Cape Leopard male’s home range can be anything from 200 to 1 000 square kilometres in size, typically spanning that of a few females, compared to savannah males with a home range typically from 25 to 50 square kilometres.
Cape Leopard inhabit some of the most inhospitable environments and habitats. The low-nutrient soils of the Cape Fynbos mountains yield often unpalatable species of plants, or plants with high tannin levels, resulting in very few large herbivores in these areas. This results in the Cape Leopard having a wide range of smaller prey, ranging from porcupine, dassie and hares, to small antelope or the young of larger antelope and zebra, birds, aardvark, small carnivores and mice.
Kills are typically dragged to a quiet place, a gulley or into dense thickets, and not into trees as is the case in the northern populations where other predators and scavengers threaten to steal their kills. The Cape Leopard is opportunistic about food sources and has adapted well to change, which is essential for this member of the Big Five to roam freely and virtually undetected so close to humans outside of protected areas. These are the apex predators of the Cape, and also the main predator of three of the other animals mentioned here: Rock Hyrax, Klipspringer and Kudu. They play an important role in maintaining the fragile balance in the food chain necessary for a healthy ecosystem.
Leopards are solitary animals, only coming together to mate. Typically, females give birth to two or three cubs in a litter, with a high mortality rate in the first six months of a cub’s life due to harsh conditions in the Cape mountains. Cubs become independent at around 22 months old. Snakebites and territorial killings by other leopards pose more natural threats to leopard cubs before they reach this age, but are overshadowed by those posed by humans, with roads, illegal poisoning, unnaturally frequent veld fires, snares, leopard traps and habitat loss, all threats to the survival of these isolated southern populations of big cats.
Based on the home range size estimates provided by the Cape Leopard Trust, we have a healthy and thriving population of Cape Mountain Leopard and we are overjoyed to announce that a female with cub was photographed a couple of months ago, which indicates that they are breeding here too.
The mountainous terrain at Bosch Luys Kloof, with its abundance of natural prey, provides an ideal habitat for the Verreaux’s Eagle – once known as the Black Eagle, and the apex avian predator in the Western Cape. Females are larger than males and can weigh in at 4.5kg, with males slightly smaller at around 3.7kg. Their wingspan can reach a whopping 2.8m, but is typically around 2m from tip to tip.
The distribution of these large eagles closely follows that of their main prey, the Rock Hyrax. Adult eagles are territorial residents in an area, monogamous, with a pair bond that lasts for many years, if not a lifetime. Unmistakeable and majestic when soaring through the skies, a pair typically remains close to one another for up to 95% of the day. They nest in the winter months, high up on inaccessible cliffs, on a nest built of sticks lined with green leaves. Mating normally takes place close to the nest site. Two eggs are often laid, but there is a high rate of siblicide, with the first-hatched chick relentlessly attacking and killing the younger chick. Most often only one chick is raised, resulting in a 50% survival rate before the chicks even fledge.
Verreaux’s Eagles are excellent at hunting as a pair. The first bird will often fly past cliffs in plain view to flush the prey for the following bird to catch. They have also been known to panic Rock Hyrax, causing them to fall to their death. Other mammalian prey include hares, Vervet monkeys, African porcupine, rabbits, Klipspringer, African Wild Cat, Black-Backed Jackal, Bat-Eared Fox and Springbuck. They will also feed on birds such as Cape Spurfowl and Egyptian Goose, reptiles and sometimes eggs.
Verreaux’s Eagles feed on carrion occasionally, and this has led to persecution and illegal poisoning, particularly by sheep farmers, which affects the survival of these birds. We have at least one known nesting site on the reserve. In 2018, no fewer than seven different Verreaux’s Eagles were counted on one guided drive, and they can often be seen circling high overhead.
Bosch Luys Kloof is an ideal habitat for the Rock Hyrax, which is locally referred to as a Dassie. These medium-sized terrestrial mammals may seem rodent-like, but their closest evolutionary relationships lie with the African Elephant and Dugong. They are often seen scuttling across the road in Seweweekspoort and on the Bosch Luys Kloof pass, rushing to seek shelter in natural rock crevices and cavities where they make their dens.
Arguably the dominant herbivores in rocky habitats, they reach biomasses comparable to successful plains antelope. They are also a vital source of food – not only for our two apex predators, the Cape Leopard and Verreaux’s Eagle – but are also preyed upon by Honey Badger, owls, jackals, Caracal and their young by African Wild Cat, mongoose and even snakes.
The Rock Hyrax is easily the most frequent item on the Verreaux’s Eagles’ menu and they have developed a series of alarm calls when eagles are soaring overhead. They struggle to regulate their own body temperatures and, like reptiles, cleverly use the environment to avoid extremes of temperature and humidity. They typically sunbathe in the morning, within reach of shelter amongst cracks or crevices in the rock, to avoid the midday sun. At night they shelter in these dens, places where temperature and humidity fluctuate half as much as outside. The rubbery soles of their feet are kept moist by sweat glands and assist in climbing and clambering across rock surfaces, with four front and three rear toes equipped with rounded, hooflike nails.
The Rock Hyrax feeds on a wide variety of plants, and although they prefer to graze, will readily browse on leaves, bark and fruits depending on the season. Typically, feeding takes place on the ground, but they readily climb into trees and bushes to access food and have often been mistaken for a totally different species, the Tree Hyrax (Dendrohyrax arboreus) in these instances.
Dassies have a very long gestation period for such a small mammal, 7 to 8 months, which is likely a legacy from their larger ancestors, after which between 1 and 6 (average 2 or 3) perfectly formed miniature versions of the adults are born in September or October, eyes open and able to move about soon after birth. They suckle for up to 3 months, but will sample vegetation within 2 days after being born.
Dassies are fond of company, with a dominant male taking leadership over a harem of several, often related, females and their young. Adolescent males are forced to disperse between the ages of 17 and 24 months and will typically travel more than 2km in search of a suitable undefended rocky outcrop. Most often, however, they end up as peripheral males living on the margin of a different colony’s territory. It is typically from these peripheral males that a challenger for the role of the next dominant male will come. Adolescent females remain with their colony.
The Rock Hyrax plays a very important role in the ecosystem, and is such an iconic part of the rocky and mountainous Karoo, that we felt it certainly deserved a mention here.