Posts Tagged ‘nature’

This morning, Wednesday 15th of August 2012, the small town of Aus in the south of Namibia awoke to a unusual weather phenomenon. It was snowing!

Have a look at the pictures below taken by Piet Swiegers owner of the Desert Horse Inn in Aus:

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To read more about the town of Aus, follow this link: http://en.wikipedia.org/wiki/Aus,_Namibia


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Kalahari’s sands harbour unusual treasure. The Devil’s Claw is one such gem, known to indigenous people for centuries for its medicinal properties. Although its name stems from the claw-like hooks of the thorny fruit, it is the secondary tubers of the Harpagophytum procumbens that are harvested for their analgesic and anti-inflammatory properties.

Devil's Claw, issued in 2005, artist: Anja Denker

Devil’s Claw, issued in 2005, artist: Anja Denker

One of Namibia’s most famous plants, Devil’s Claw, called Kamangu by many ethnic groups, is known traditionally as an all-purpose tonic, assisting with ailments such as chest pains, emaciation, weakness, fatigue, urinary problems, digestive disorders and fever. The infusion is also taken as an analgesic, especially during pregnancy, and an ointment is applied to heal sores, ulcers and boils. It has become well-known in the western world in the last fifty years as a treatment for rheumatism and arthritis.

The creeping perennial with grey-green leaves and tubular mauve flowers that appear from November onwards is endemic to southern Africa, growing predominantly in the Kalahari sands of Namibia, Botswana and South Africa. It belongs to the Pedaliaceae family. The fruit is dispersed by attaching to animals’ fur and the seeds may remain dormant for decades. The cassava-like secondary roots are sliced and dried for medicinal purposes. Traditionally, an infusion is made by mixing the powdered material with boiling water. Capsules, tablets, tinctures and ointments are also now available.

In the 1950s, the medicinal value of Harpagophytum was recognised by a German farmer in Namibia and the first major commercial export of Devil’s Claw began in the 1960s. The international demand increased in the 1990s. Today, Namibia is responsible for a large percentage of the supply of Devil’s Claw, which is mostly wild-harvested by rural people. Devil’s Claw was listed as a protected species in Namibia in 1977 and permits are required to harvest and import the plant. Thousands of harvesters living in remote rural areas rely on the harvesting of Devil’s Claw as their sole cash income.

Leaves, blossoms and thorny fruits of the Devil's Claw. Photo: Wikipedia/CITES Secretariat (http://en.wikipedia.org/wiki/Harpagophytum)

Leaves, blossoms and thorny fruits of the Devil’s Claw. Photo: Wikipedia/CITES Secretariat (http://en.wikipedia.org/wiki/Harpagophytum)

A large amount of Devil’s Claw is harvested in the Nyae Nyae Conservancy in eastern Namibia. The conservancy works closely with the Ministry of Environment and Tourism to ensure the sustainability of Devil’s Claw. In the last few years, NGO funding enabled the Nyae Nyae Development Foundation of Namibia (NNDFN) to work with the Centre for Research Information Action in Africa – Southern African Development and Consulting (CRIAA SA-DC) to introduce and implement a sustainable harvesting programme. This also ensures quality of the product and prevents exploitation of the harvesters.

There is concern that Devil’s Claw is threatened by over-utilisation. Studies reveal a need for harvesting to be controlled and restricted to certain months of the year, so as not to disturb the plant during the growing season. It has also been ascertained that although the secondary tubers can be harvested, the primary tap roots must not be disturbed to allow plant regeneration and population growth, ensuring Devil’s Claw survival. Harvesting quotas and long-term monitoring of this valuable resource, which lies so unassumingly on the desert sands, are also recommended.

Resembling a weed, Devil’s Claw could easily be overlooked without its beneficial properties ever being realised. Thanks to indigenous peoples, like the San, we have been made aware of the untold treasures of the natural world.

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The black eagle or Verreaux’s eagle, as it’s officially called, is one of four large African eagle species – the others being the martial eagle, crowned eagle and our national bird, the African fish eagle – each specializing in a different ecosystem.

Black Eagle. Photo: Jutta Luft, Wikipedia

Black Eagle. Photo: Jutta Luft, Wikipedia

This king of the skies inhabits mountains, hills, cliffs and broken rocky habitats throughout southern and eastern Africa, from Table Mountain to Israel, excluding the Kalahari basin. There are about 500 to 1000 pairs of black eagles in Namibia, from the cliffs of the Orange and Fish rivers and the Karas Mountains in the south through the western escarpment belt, the Khomas Hochland, the Waterberg, Kaokoveld and to the Kunene River in the north.

Verreaux’s eagle, Aquila verreauxii, has a wingspan of about 2 m and like most birds of prey (‘raptors’) the female (±4.5 kg) is larger than the male (±3.7 kg). One of the reasons for this may be because smaller males are more agile and proficient hunters, while females need a good supply of body fat reserves to incubate eggs and brood small nestlings for long periods.

The eagle’s main prey is the rock hyrax or dassie. In some areas where hyrax are plentiful and readily accessible they may comprise 90% or more of the eagle’s diet while in other areas they comprise as little as 50%, with other medium sized mammals (e.g. hares, rabbits, small antelopes) and medium to large birds (e.g. guineafowl, francolin and bustards) making up the balance. Verreaux’s eagle will also scavenge. It sits imperiously on top of a carcass which, if it is a sheep, leads farmers to assume that the eagle killed the animal.

Seven such incidents were investigated with farmers and in six it was found that the sheep died of other causes, mainly predation by domestic dogs, birth problems or disease. In the 1970s and early 1980s farmers in the Karas Mountains, because of perceptions of small-stock predation, largely eliminated Verreaux’s eagles from the area. This resulted in an explosion of rock hyrax, which ventured out far from their rocky areas over the plains where they competed with small-stock for grazing. (Twelve hyrax eat the same amount of grass as one karakul sheep.) Once the Karas farmers understood this they started protecting Verreaux’s eagles and today the Karas Mountains once again supports a healthy population of this magnificent eagle.

Aquila verreauxii (Black Eagle), issued in 1975, artist: Dick Findlay

Aquila verreauxii (Black Eagle), issued in 1975, artist: Dick Findlay

The nest is a large stick platform lined with green leaves, usually built high on a ledge on a sheer cliff face, safe from baboons. Verreaux’s eagles are monogamous, forming lifelong pair bonds, and are territorial, defending their home range. Breeding starts in late April and May with spectacular courtship flights and displays. The peak egg-laying season in Namibia is June and most clutches comprise two eggs. The eggs usually hatch 2-3 days apart after an incubation period of 45 days.

On hatching, one of the most interesting biological events takes place. The first chick to hatch, which is larger and more developed, attacks the second in what has become known as the Cain and Abel struggle. Reasons suggested for this are that the second egg serves as a reserve in case the first is infertile and that one fit young eagle has a better chance of surviving and ultimately rearing offspring than two less fit young eagles. The fledgling leaves the nest for the first time at about 95 days after hatching, and is chased from the territory about 30 days later.

Verreaux’s Eagle is listed as ‘Near Threatened’ on the Namibian Red Data list because of persecution from small-stock farmers and because it is vulnerable to the use of poison, usually set to kill mammalian predators of small-stock. It is a sad fact that, for every target species killed in this way, over a hundred non-target scavengers are poisoned, most of them vultures and scavenging eagles. Fortunately, because of the remote mountainous terrain in which they live, the population of Verreaux’s eagle in Namibia is stable.

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Few tortoise species are as well-known as the African leopard tortoise (Stigmochelys pardalis, former scientific name: Geochelone pardalis). The reasons for being so easily recognised are their attractive markings, appealing size (in some areas females may reach up to 70 cm!) and their distribution throughout Africa.
Leopard tortoise. Photo: Alfred Schleicher

Leopard tortoise. Photo: Alfred Schleicher

Leopard tortoises are found in an area stretching from southern Sudan and parts of Somalia across Kenya and Tanzania in East Africa and all over southern Africa. This versatile species occurs in Mozambique and South Africa as well as Zimbabwe, Botswana and Zambia, in the arid regions of Namibia as much as in the rain forests of Angola, no matter whether annual rainfall is just 100 mm or well above 2,000 mm.

The leopard tortoise favours semi-arid thorny to grassland habitats but seems to thrive anywhere from coastal to mountainous landscapes. It is able to cope with heat as well as extreme cold, aridity as well as humidity. Tortoises in the Mountain Zebra National Park near Cradock in South Africa are known to dwell in the abandoned holes of small predators during the cold winter months. Likewise, in the arid scenery around the Tiras Mountains in southern Namibia, they shelter in similar holes to survive the heat and extended periods of drought. There, however, the occurrence of leopard tortoises is no doubt proportionately much smaller than it is in the vast savannah of Serengeti National Park in East Africa, for example.

Leopard tortoises are herbivores which graze on grasses like lawnmowers. They also favour various fruits, succulents and thistles and even eat the dung of other herbivores. The key to success seems to be versatility combined with resilience.

Adaptability is also reflected in the reptiles’ size within different tortoise populations. The largest ones are found in areas where food is plentiful and, perhaps, where the reptiles have enough time to grow. In many African cultures large leopard tortoises are seen as a food source. For the San (Bushmen) in the Kalahari this tortoise used to be a special treat and the empty shells were treasured as containers for collecting berries and roots. But the numbers of tortoises always remained stable, even though baby tortoises have many natural enemies to contend with – hornbills, eagles, hawks and secretary birds. Bush fires are another threat.

Geochelone pardalis (Leopard tortoise), issued in 1982, artist: Arthur Howard Barrett

Geochelone pardalis (Leopard tortoise), issued in 1982, artist: Arthur Howard Barrett

Leopard tortoises are very prolific. In years with generous rainfalls females lay up to three clutches of up to 12 (sometimes 20) eggs each, even in Namibia. Eggs are the size of a ping-pong ball. Females, as in all tortoise species, use the strong nails of their hind legs to dig a nesting hole of 30 to 35 cm deep. They moisten it by emptying their anal bladder and then, sliding down the hind leg, one egg after the other is dropped to its place in the hole. After the last one the nesting site is carefully covered up again and smoothed over with the plastron to make it less conspicuous.

Incubation time differs from 80 to 120 days in areas which are humid and always warm, to more than one year in mainly arid regions – like Namibia, for example. This is another form of amazing adaptability: if the rains stay away the hatchlings would find no grass and starve. It does in fact happen that fully developed baby tortoises hatch but stay in their nesting hole in a state of ‘drought hibernation’, waiting for the proverbial better times. After sufficient rain has fallen they will finally make their appearance. In typical tortoise manner the baby ‘leopards’ are immediately able to look after themselves without restriction and have all four little feet firmly planted on the ground.

In some parts of their original habitats leopard tortoises have nevertheless become rare. The reason will most certainly be the impact of the most destructive of all living creatures, modern man. Because even the most adaptable species are unable to cope with fast changes in their habitat. Perhaps we, as humans, should take a leaf out of that book.

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It’s surprising to think of penguins in the African heat rather than in colder climes, but the African penguinis endemic to the southern tip of Africa. An unusual flightless bird, ungainly on land, it is an agile master of the water world as it careens swiftly through the water powered by its webbed feet and small flipper-like ‘wings’.Because of its loud braying call, it was once referred to as the Jackass penguin. The tough 60-70 cm bird has an attractive black-and-white colouring that serves as camouflage; the white underbelly to disguise it from underwater predators below and the black back from predators above. Its disguise has not protected it, however, from its greatest competitor – man, and African penguin numbers have plummeted over the last century to a fraction of what they were. In 1956/57 the total population was estimated at 141 000 breeding pairs, a number which had decreased by 60% in 2009 to just over 25 000. The Namibian population comprised approximately 5 000 pairs in 2008/9 and the South African, 21 000.Historically, the decline in penguin numbers has been attributed to the harvesting of penguin eggs and the collection of guano. Without the guano layer, penguins are unable to dig their burrows, which protect them from predators and provide cover from the hot African sun.

Jackass Penguin, issued in 1997, artist: David Thorpe

Jackass Penguin, issued in 1997, artist: David Thorpe

The African penguin is now facing an even more severe crisis – food scarcity, being unable to compete with the commercial fisheries. Many penguin mortalities have also resulted from oil spills. Natural predators include seals and sharks in the ocean and the mongoose, gull and genet on land. The dramatic decline in numbers led to the African penguin being reclassified on the IUCN’s Red List in 2010 from Vulnerable to Endangered.The distribution of the African penguin Spheniscus demersuscoincides with the area influenced by the nutrient rich waters of the Benguela Current that runs up the coast of Africa and the availability of off-shore nesting sites. (Some mainland sites have been colonised in recent years. This has been attributed to an eastward shift of pelagic fish.) Its breeding range extends from Hollamsbird Island, off central Namibia, to Bird Island in Algoa Bay in the Eastern Cape. In Namibia, Halifax Island, Mercury, Ichaboe and Possession islands account for approximately 96% of the Namibian penguin population. Sardines and anchovies, the penguins preferred diet, were overfished in the 1960s/70s making it difficult for penguins on islands like Halifax to find food. The guano layer covering the island was also removed for fertiliser during this period.Several distinctive behaviours are evident in the penguin colonies during the year, most noticeably the annual moult, where penguins fatten-up for weeks before their 20-day starvation period when they are unable to enter the ocean, and the breeding season. In Namibia most penguins moult in April and May, and in South Africa from November to January.

African penguin. Photo: Gondwana Collection

African penguin. Photo: Gondwana Collection

There are also regional differences of breeding season, with the peak of the breeding season occurring in Namibia in November and December and in South Africa from March to May. The African penguin is monogamous, the breeding pair sharing the 40-day incubation and feeding duties. About 60 days after hatching, the chicks’ down has already been replaced by blue-grey waterproof plumage, and from 60 to 130 days the ‘baby-blues’ are ready to leave their natal colony. They will return after 12 to 22 months, after journeys of up to 1 900 km, to moult into adult plumage.There are ‘happy feet’ and success stories these days as more protection is being granted to the species, nesting boxes supplied and organisations like SANCCOB (South African Foundation for the Conservation of Coastal Birds) rehabilitating abandoned chicks and oiled birds. Over a hundred birds from Lüderitz were transported to Cape Town in a rescue mission in 2009 where the oiled penguins spent 4 weeks rehabilitating before their release and long swim back to Namibian waters. After 18 days, the first of the group were seen arriving home.

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From close by it resembles a climbing wall for free climbers: Vingerklip is 35 metres high, about 15 metres wide and dotted with protruding stones. In 1973 the rock stack in the valley of the seasonal Ugab River, some 40 km east of Khorixas, was indeed conquered in free climbing manner by Udo Kleyenstuber, who ascended on its east side. The hooks which can still be seen were left by American mountaineer Tom Choate who is credited with the first ascent of Vingerklip in 1970.

For geologists, on the other hand, the erosional rock formation is like a book in which they can read stories that happened millions of years ago and shaped this landscape. They are captivating stories about sea levels dropping and rising, wet and dry phases of the climate, torrential rivers, chalky soil and rivulets that cause rocks to split. Even laypersons will notice that Vingerklip consists of different layers – layers of large stones alternate with layers of fine sand. They testify to the fact that at times the Ugab flowed rapidly enough to drag rocks with it, while at others it was so sluggish that sand was deposited in its bed.

Vingerklip/Outjo, issued in 1986, artist: Johan van Niekerk

Vingerklip/Outjo, issued in 1986, artist: Johan van Niekerk

Knowing this much it already becomes clear that it was the Ugab River that sculpted Vingerklip. These days a seasonal river which comes down in flood only after sufficient rainfalls, the Ugab rises in the western foothills of the Otavi Mountains, then passes south of Outjo and north of Brandberg Mountain to reach the Atlantic Ocean about 180 km north of Swakopmund.

Some 120 million years ago, as the southern supercontinent of Gondwana breaks up and South America drifts away, the southern African plate rises and so does its gradient to the sea level. Thus the erosional force of the rivers increases further. Southwest of Outjo the Ugab cuts its course deeper and deeper into the rock. Then, towards the end of the ice age 20 to 10 million years ago, the sea level rises again and a wetter climate prevails. The Ugab River fills the valley, which it created earlier, with rocks and sand. Layer is deposited upon layer, up to a height of 100 m.

The Vingerklip in the Ugab Valley, some 40 km east of Khorixas. Photo: Gondwana Collection

Two million years ago, during the ice age in the northern hemisphere, the sea level drops again and the Ugab once more cuts deep into its course which it previously filled with rocks and sediments. Parts of the wide riverbed fall dry. As the water evaporates, minerals precipitate – most of all lime because the Ugab and its tributaries drain the soil west of the Otavi Mountains and around Outjo which contains carbonate. The precipitated lime works like cement and binds rocks and sand into a conglomerate which is as hard as concrete. The deeper the river cuts into its original bed the narrower it becomes, forming several terraces over time.

The ‘cement’ in the conglomerate, i.e. the lime, is dissolved again by rain. This results in rivulets and streams which gradually cut into the terraces as if they were a cake. Erosion continues to gnaw on the edges of these pieces of cake, causing them to shrink and the gaps between them to widen as time passes. Vingerklip is the remainder of one such piece of cake, albeit not the only one: from its base another two, larger terrace islands can be seen in the Ugab Valley.

Furthermore, three different terraces can be distinguished. There is the ‘old’ main terrace, the plateau of which now rises some 160 m above the current riverbed, while the surface of a younger terrace lies about 100 m and that of the youngest one some 30 m above the Ugab.

Since this area does not experience much rain, chances are that Vingerklip will remain for years to come. It sits on a sound wide base with a circumference of 44 metres – in contrast to the Finger of God in southern Namibia, which collapsed in December 1988.

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A true desert bloom crowned in the springtime by large disc-shaped crimson flowers, Hoodia has received much attention over the years, not for its ability to store moisture and thrive in arid areas or for its exquisite blooms but rather for its use as an appetite suppressant. In the last decade it has been universally acknowledged that the San/Bushmen, the oldest inhabitants of southern Africa, own the rights to the indigenous knowledge of the plant, but that has not always been the case.



The plant was used by the San for millennia as an appetite suppressant and thirst quencher (also as a treatment for high blood-pressure, diabetes and as a cure for abdominal cramps, haemorrhoids, tuberculosis, indigestion and hypertension), long before it was sought after in a western world in its battle with obesity.

The species of most interest in the family Apocynaceae for its appetite-suppressing qualities is Hoodia gordonii found predominantly in southern Namibia and north-western South Africa. The spiny-stemmed succulent grows in gravel or shale plains, Kalahari sands or on dry stony slopes. It can tolerate temperatures exceeding 40˚C and as low as -4˚C. Incredibly, a single plant can have as many as fifty branches growing from its base, can grow up to a metre high and weigh as much as thirty kilograms. Although eye-catching, the flowers referred to as stapeliads, are only attractive to its pollinators – flies and blowflies – with their strong carrion-like odour.

Hoodia with yellow flowers in the Gondwana Cañon Park.  Photo: Mannfred Goldbeck

Hoodia with yellow flowers in the Gondwana Cañon Park. Photo: Mannfred Goldbeck

The first Europeans to encounter Hoodia gordonii were Paterson and Col RF Gordon, who in December 1778 found specimens in the Upington area. Botanist, Francis Masson, recorded the use of Stapelia gordonii on his visits to the Cape around the same period. It was later transferred into the Hoodia genus, so named after dedicated succulent grower, Van Hood.

Hoodia is a protected plant in Namibia and a permit is required from the  for cultivation or harvesting, relocation or trade. It is also listed on the Convention of International Trade in Endangered Species of Fauna and Flora (CITES), Appendix 2, regulating international trade.

The Council for Scientific and Industrial Research (CSIR) in South Africa began to include Hoodia in its projects as early as 1963 and in 1995 it filed for a patent application for use of the active components (it had isolated the active compound – P57) responsible for appetite suppression. It later signed licensing agreements with UK pharmaceutical company Phytopharm that in turn sub-licensed the rights.

Hoodia bainii, issued in 1973, artist: Dick Findley

Hoodia bainii, issued in 1973, artist: Dick Findley

In June 2001, a South African-based NGO, Biowatch South Africa, with assistance from the international NGO, Action Aid, alerted the foreign media to the fact that the San had not been involved in the development or commercialisation of the Hoodia products, leading CSIR to enter into negotiations with the San. They were represented by the Working Group of Indigenous Minorities in Southern Africa (WIMSA), the South African San Council and the San Institute of South Africa (SASI). This culminated in the CSIR and the South African San Council signing a benefit-sharing agreement in March 2003 with the San receiving a percentage of the royalties.

In August 2004, the San Trust, formally named the San Hoodia Benefit Sharing Trust, was registered, with 75 percent of all Trust income to be equally distributed to the San Councils of Namibia, Botswana and South Africa.

The bottles of weight-loss products lining pharmacy shelves have little resemblance to the hardy desert plant that survives in the Namib Desert, its soft sensual bloom belying its tough existence, and its recent history is far removed from the time when the San still freely lived off the land and roamed the southern sands of Africa.

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