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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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According to African folklore, Leopard stopped sharing his meals and started to hide his kills in trees because Jackal and Hyena weren’t reciprocating his generosity and Leopardess became wary because Hare ate her cubs. One of the best remembered fables of the ages is, however, ‘How the Leopard Got His Spots’ in the ‘Just So Stories’, where Rudyard Kipling elucidates the benefits of camouflage. Leopard looked ‘like a sunflower against a tarred fence’ when he entered the forest from the veld until the Ethiopian kindly painted the five-dotted rosettes which cover the leopard’s coat to this day.
Leopard Panthera pardus, issued in 2009, artist: Helge Denker

Leopard Panthera pardus, issued in 2009, artist: Helge Denker

The fable holds much truth, as it has been discovered that the patterns and colours of wild cats evolved over the centuries to blend into their specific habitat. A leopard will be better suited to the dappled light of its wooded environment, if it has spots. Many other interesting facts about leopards are also not common knowledge.

The word ‘leopard’ stems from the Greek words leōn (lion) and pardos (panther), and the ancient belief that it is a hybrid of both. The genus Panthera, including the other three big cats – lion, jaguar and tiger – is thought to have emerged in Asia, with ancestors of the leopard and lion migrating into Africa. The last common ancestor of these big cats is said to have lived about 6.37 million years ago. The leopard has featured in the art, mythology and folklore of many countries where it has historically occurred from ancient Greece to Rome. Black panthers (uncommon in Africa) are melanistic leopards or jaguars, having recessive genes causing their dark colouring.

As powerful as the leopard is, it is shy and avoids confrontation, and would seem, if one was inclined to anthropomorphise, to have an inferiority complex, often letting lion and hyena steal its kills. If it doesn’t have the advantage of cover and surprise, it will often quickly disappear into foliage; a fleeting image of power and grace.

The most widespread (from Asia to Africa), adaptable and successful of the big cats will also usually avoid high risk situations, preparing to play it safe. Although it is an opportunistic hunter and enjoys a varied diet from insects to antelope, it will mostly target medium-sized animals in small herds where there is a low risk of injury. It is a fallacy that baboons are its favourite food as they are too vocal and dangerous for the leopard to make hunting them a common occurrence. A leopard will also not risk injury by defending a kill.

Deadly surprise for this baboon... Photo: John Dominis

Deadly surprise for this baboon... Photo: John Dominis

Although the leopard is a renowned climber, known to be able to carry prey of over 50 kg up into a tree, which it uses as a refuge and larder, and can often be seen comfortably perched in a tree with legs dangling over the branches, it is also a proficient swimmer. The leopard, Panthera pardus, relies on its stealth to surprise its prey. If it is unsuccessful on the first attempt, it will often give up. It is extremely agile however, and can reach speeds of 60 km/h for short distances.

Because the leopard is a solitary animal, there is the chance that males and females may miss opportune periods for mating. There is, therefore, no specific breeding season, and ovulation is induced by mating.

A master of camouflage and stealth, the leopard’s secretive existence has ensured its survival. Although its tracks may be observed in many areas, it is rarely seen, remaining elusive like an apparition, dream or vision. When walking amongst the trees, in the mountains or in the Fish River Canyon, you may have the slight unsettling feeling that Leopard is watching from above, perfectly blended into his mottled background.

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