Background information fact: by edgardowelelo@yahoo.com, Master of the Game
The great plains cover more than a quarter of the land on Planet Earth. These hugely productive, vast open spaces are fuelled by grass and support the greatest gatherings of wildlife anywhere on the Planet Earth. Great plains are found on every continent except Antarctica. They range from the baking Savannahs of Africa to the frozen tundra of the Arctic, from the sweeping prairies of North America to the tall – grass pampas of South America, and from the lush, lowland floodplains of India to the harsh, high – altitude steppes of the Tibetan plateau. Together they cover a quarter of the Planet Earth.
The central Asian steppes alone stretch unbroken nearly a third of the way around the world. The great plains are also hugely productive. Nowhere else do you find such large concentrations of animals -1.5 million wildebeest on the East African Serengeti Savannah, up to 2 million gazelles roaming the Mongolian steppes and more than 3 million Caribou on the North American tundra. Millions of grass – eaters in turn feed thousands of plains predators, from lions and hyenas in Africa to wolves and eagles in America and Asia. Though the names for plains may vary – steppe, savannah, prairie, pampas – these great oceans of grass have two things in common. First, they occur where rainfall is too low to support forests and too high for deserts to develop (250 – 750mm, 10-29 inches, per year). Second, they have a distinct growing season – when the tropical rains or the temperate summer arrives and grass dominates.
TUNDRA SAFARIS
Travel north beyond the tree line and you emerge onto the Arctic tundra – a windswept wilderness larger than Australia that encircles the Arctic Ocean at the top of the world. Virtually unpopulated and devoid of life in the frozen, dark winter, the tundra undergoes a transformation in summer. When land temperatures rise above zero long enough for ice and snow to melt, light, warmth and moisture are suddenly available, and nutrients that have been locked in the frozen soil are released. As the ice recedes, the first grass shoots emerge, and within days there is a rich supply of food. This, together with few predators – the result of its remoteness – and 24 – hour daylight in summer, makes the tundra the perfect place to raise offspring. Animals are drawn here in their millions, including birds and mammals that have overwintered far to the south.
THE WORLD’S BIGGEST BARNYARD
Migration can transform the barren tundra almost overnight. In early May, though much of the snow has melted, the Egg River on Banks Island in the far north of Canada seems like the emptiest place on Planet Earth. Crushed and scoured flat over millennia by the abrasive powers of ice and wind, the plain ahead is featureless apart from patches of snow. The only sound is the wind. But all that is about to change, literally overnight. One day at the end of May, an incredible noise fills the air – a honking and squawking that marks the arrival of hundreds of thousands of lesser snow geese. This is the end of a 12 – week, 4000 – km (2485 mile) safari from their wintering grounds along the Gulf of Mexico and the southern US.
The plains around the Egg River are transformed instantly from vacant tundra into a huge BARNYARD – a breeding colony of half a million geese 20km (12.5 miles) long and 5km (3 miles) wide. Male and female lesser snow geese pair for life and tend to return to same breeding sites each year, forming the biggest and most dense nesting concentrations of waterfowl in the world. Nests in a colony are spread out over the tundra roughly 10m (33 feet) apart – far enough from each other to avoid conflict with the neighbours but close enough for protection against predators. From a distance, the pairs of geese appear like thousands upon thousands of golf balls scattered over the ground. Snow geese usually lay four or five eggs, which are incubated by the female. She sits tight for the next month, during which time she may lose 25 per cent of her body weight. Her partner guards her and the nest from intruding geese and predators – gulls, which pick off unattended eggs, and the resident Arctic foxes. A pair of foxes will often den within the goose colony or just at the edge, though they have only a month to take advantage of the sudden bounty on their doorstep.
Taking an egg requires skill. As soon as an Arctic fox approaches a nesting pair, the alarm goes off and a ripple of activity sweeps through the colony as the fox runs a gauntlet of furious ganders, beating their wings and biting. When it has chosen a nest, the fox will dodge and weave around it, trying to draw the enraged geese away from their eggs. As the goose joins her partner in the attack, the fox darts forward, pinches an egg and flees, with the birds in panicked pursuit. Some eggs are eaten, some are fed to the cubs and the rest are buried for later in the year. Very occasionally, a fox will catch an adult goose and make a real killing.
Hatching is highly synchronized, and 23 days after nesting, the whole colony is suddenly awash with fluffy yellow goslings. Foxes gather up as many as they can steal from the protective parents and carry them back to the cubs at the den – in a good year, foxes can rear up to 15 young. But the foxes don’t have long to feast. Within 48 hours, most of the goslings have been led away by their parents to the safety of the lakes and rivers that pattern the tundra. As quickly as they arrived, these geese are gone, and once again the Egg River feels like the loneliest place on Planet Earth. They disperse across the plain, where for the next two months, the goose families feed on insects and grass. Left behind, the Arctic foxes survive on what they managed to stash during the period of plenty, and their fat reserves, on the odd ptarmigan and lemming and by scavenging the carcasses of caribou and other animals.
THE BIGGEST HERDS OF ALL
At the same time as the snow geese are heading north, 3 million caribou (North American reindeer) are embarking on the longest of all land migrations. Moving through snowy forests, crossing icy rivers and braving bears and wolves along the way, they head for the tundra across Alaska and northern Canada – a round safari of up to 3000km (1865 miles). Like the snow geese, they migrate to the tundra to feed on the new growth and raise their young as far as possible from predators. Pregnant caribou lead the way, travelling as much as 50km (31 miles) a day. They reach their calving grounds by mid – June, returning to a broadly similar area, the exact location depending on weather, snow and the condition of the females. Some bears and wolves live far enough north to take advantage of the births. But the calves are well adapted; they can stand almost at birth and run within a day (precocial). Caribou remain fairly spread out at the calving grounds for a week or two and then gather together in large herds to move off to new pastures. By now the calves are walking up to 14km (9 miles) a day, fording lakes and rivers with their mothers. But this time they are moving not just to find new grass but to escape the clouds of mosquitoes that engulf you wherever you walk. On windless, warm summer days, swarms are so dense that you find yourself breathing them in, and the only thing to do is to keep moving. The caribou herds walk into the wind or to higher ground where there is a breeze of seek out any remaining snow – anything to gain relief from irritating insects. This constant movement, missed feeding time and blood loss from insect bites cause caribou to lose weight during a time when they need to be storing fat. After calm summers with high insect harassment, calves do not grow as big, and fewer survive the winter. Flies and mosquitoes can bite through thick cotton shirts, and so the only way to wait out on the tundra for the late – June – caribou spectacle is to wear a mosquito net over your whole body. The Bathurst Herd in the Barrenlands of northern Canada move off the calving grounds in spectacular fashion. On calm days, groups of up to 60,000, packed tightly together to protect themselves from insect attack, flow across the landscape as one. Herds do not move in a straight line or follow a totally predictable route and are constantly on the move, and so even a substantial number of caribou can be surprisingly hard to locate on the vast tundra. But if you find one heading your way, sit perfectly still, and it may sweep either side of you, within touching distance, mothers and calves are always grunting to each other so as not to get separated, moving fast over the rough tundra in a rhythmic trot.
Wolf packs are a constant threat and, for some herds, may be responsible for up to 70 per cent of all calf deaths. Sometimes the caribou herd is so large that the individuals at the head are still grazing, oblivious to the mayhem behind them. Once a calf is singled out, the hunt becomes an endurance race. The wolf will chase the calf until one or other becomes exhausted and gives up, which can be up to 8km (5 miles) later. As the brief Arctic summer ends, the caribou head back south to spend the winter sheltering and feeding in the forests. Soon the plains are empty once again. Walking across the Barrenlands, you occasionally meet a lone caribou calf lost and heading in the wrong direction. When it sees you, it runs over bleating eagerly, only to find that you are not its mother. During the migration, the river crossings and the wolf hunts, many caribou calves become separated and perish. Their carcasses will become food for the scavenging ravens, bears and Arctic foxes left behind.
KEEPING ONE STEP AHEAD
On the great plains of Africa, seasonal tropical rainfall means that grass and water are available in different places at different times. During the dry season in East Africa, more than 1.5 million wildebeest traverse the baking plains and cross crocodile – infested waters in search of food and water. In the wet season, they migrate to areas of fresh grass rich in phosphorous, needed to produce milk and promote healthy bone growth – vital for their newborn calves. By keeping on the move, they also stay one step ahead of many of the predators. Lions, cheetahs, jackals and leopards do not shadow the migration – they are tied to specific areas by the need to defend a territory and protect their young. Hyenas, however commute between their cubs at the den and the migrating herds of wildebeest – a round trip of up to 140km (82 miles) – and mothers can be absent for as long as four days. It is a strategy that seems to be successful in the Serengeti, where spotted hyenas are the most abundant large carnivores. On the tundra, caribou migrate as far away from the wolves as they can for calving. So the Arctic wolves, which also have young at this time, must leave their cubs alone at the den, just as the hyenas have to do, and commute to the caribou herds. Finding the herds on the vast tundra requires great endurance and can involve a round – trip of up to 200km (125 miles). On the steppes of Mongolia, the last remaining great Asian migration takes place, with possibly up to 2 million Mongolian gazelles moving between their winter breeding grounds and their summer calving areas. During their migration is probably a combination of predator avoidance, insect harassment, the search for minerals and good grazing, and the extent of winter snow cover, though the exact reasons are still being researched.
BOOM AND BUST
Many of the great migrations are now a shadow of their previous extent, and many of the species are threatened – due largely to human encroachment. A few hundred years ago, grassland would have covered almost twice its current area, but much of that land is now farmed or fenced. Hunting is also to blame. The most famous example of overhunting on the Great Plains is that of the bison of North America, more than 60 million of which once roamed the prairies. Hunting nearly wiped the species out, and though last – ditch conservation has built the population back to 350,000, it is fragmented and restricted to refuges and national parks. In southern Sudan, a million or so White – eared Kob race (large antelopes) are known to have migrated more than 1500km (930 miles) annually – a scene to rival that of the East African plains. Sudan’s recent civil war is thought to have reduced numbers dramatically, though little information exists about the current situation. In South Africa in the nineteenth century, 10 million or so springbok once trekked across the veldt. Today, springbok herds seldom number more than a few hundred, and many of their migration routes are blocked by fencing. Chiru or Tibetan antelope, still undertake a great migration across the plains of Tibet. Exactly why is not yet fully understood, and even the location of their remote calving grounds remained a mystery until a few years ago. Today, though, they number fewer than 75,000, down from possibly several million, having become victims of fashion. Hundreds of thousands have been killed for their fine wool, known as shahtoosh, which is woven into ornate shawls that can sell for up to $15,000 in New York and London. That trade has largelybeen stopped, and some parts of the Tibetan plateau are receiving protection, though poaching still continues.
NOTE AND REMEMBER (SUPER GRASS);
There are around 10,000 different species of grass. Covering the plains and feeding the great herds, this family of plants is the most widespread and abundant on Planet Earth. They (grasses) are also among the toughest. Able to withstand being burnt, frozen, drowned, parched, grazed or trampled, their secret is the fact that, unlike trees, bushes and other flowering plants, their leaves grow continuously from the base. So as they are being grazed or damaged from the top, they (grasses) are regenerating from below. Grasses are not only great survivors; they are also opportunists, capable of making use of the sun’s energy and growing rapidly when conditions are good. On the tundra, when the short summer arrives and the snow melts, grasses use their reserves to produce a full complement of leaves in just a few weeks. Some grasses can spread without setting seed by putting out runners along the surface, from which shoots and leaves can grow. During the winter, they do not die but simply stop growing and wait for the good times to come again. Many species retreat underground, remaining in a dormant state as rhizomes. The food stored in the rhizomes as starch allows them to take advantage of favourable situations when they arise. On the African plains, though, most grass species are annuals, setting seed as drought conditions return and surviving the dry season in this state. As soon as the rains come, the seeds germinate, producing new leaves within just a few days. Even a light shower can result in a green flush on the savannah.
THE SAIGA SAGA
Perhaps the most drastic population crash of any large mammal in recent years has been that of the saiga antelope of the central Asian steppes. In the early 1990s, more than a million remained. Fifteen years later, fewer than 30,000 were left. A saiga antelope is roughly the size and shape of a goat, but with a huge, bulbous, flexible snout – a comical nose with a serious function. Its generous nasal chambers have evolved to filter, moisten and warm the air before it enters the lungs, as the saiga antelope lives on the central Asian steppes of Russia, Mongolia and Kazakhstan, where the atmosphere is dry and dusty. Each autumn, as the snow starts to fall on the steppes, saiga travel to less snowy areas in the south of their range. Here they mate, and in the spring they head north again to give birth. For thousands of years they have made these journeys, and for thousands of years they have been hunted for their meat, skin and horns (used as an anti-inflammatory in traditional Chinese medicine). With the arrival of vehicles and guns, hunting became excessive, and by 1920, the population came near to extinction. Following the Russian revolution, saiga hunting was banned, and by the 1950s, the antelopes had made a remarkable recovery, increasing to more than 2 million. Numbers bounced back because saiga are well adapted to their unpredictable environment. In drought years and times of high snowfall, many starve to death – up to 80 per cent of the population. In favourable years, saiga can reproduce rapidly. Females frequently have twins (rare among antelopes), and the young are sexually mature at just eight months old – ready to mate when the winter rut starts. Recently, saiga populations have taken another hit. In the early 1990s, in a bid to save rhinos, some conservationists encouraged the use of saiga horn as an alternative to rhino horn – also used in traditional Chinese medicine. More importantly, at this time the Soviet Union was collapsing. Regulation of trade in saiga horn caused, and hunting reached new levels. Conservationists hoping for another miraculous recovery have been alarmed by recent findings. Selective hunting for males – only males have horns – means that the population is now predominantly female and cannot reproduce well enough to bounce back. The likelihood is that the saiga antelope population in Mongolia will become extinct, and if poaching is not controlled, the other populations may follow suit.
THE HIGH PLAINS
Forty million years ago, the Indian subcontinent collided with Asia, and over time, the land buckled upwards more than 8km (5 miles) into the sky to form Mount Everest and the rest of the Himalayan range. This range now divides two plains that are complete opposites. If you were to stand on the top of Everest on a cloudless day, you would see to the north the dry, desolate Tibetan plateau – the roof of the world – stretching far into the distance of Asia. To the south you would see a lush, fertile, low-lying green expanse spreading across India – the Gangetic Plains, one of the most densely populated regions of the world. Tibet is in the shadow of the mountains and receives little rain, while the Gangetic plains are soaked by the monsoon. The Tibetan plateau was once the floor of an ancient sea, and you can still find marine fossils here at more than 4000m (13,120 feet) above sea level. Today, it is an immense plain nearly four times the size of France, most of it higher than Europe’s highest peaks. When you arrive here, the first thing you notice is your own heartbeat. You feel dizzy, and your head throbs as the blood pumps faster through your body to compensate for the lack of oxygen in the thin air. The second thing you notice is that there is no one here. You do meet the occasional nomad tending sheep, but vegetation is so scant and fresh water so sporadic that you are unlikely to find many livestock or people. The spartan plateau is incredibly dry, and a desiccating wind gives you a perpetual thirst. Camping out, you can go for day after cloudless day with nothing but deep blue sky between you and rest of the universe.
Yet even in this barren landscape, grasses are able to grow. More than 70 per cent of the plateau is grassland, and there is enough plant life for hardy animals to eke out a living. From a distance, wild yak look like huge, hairy, black cows. They are exceptionally shy, but if you can crawl closer, you see what impressive beasts they are. With hair so long it nearly covers their feet, they look as if they have been draped with shaggy blankets. Females and young live in herds of up to 200, but the bulls are largely solitary. As they amble across the plains, their magnificent broad heads are slung low, their square muzzles are pressed close to the ground, nibbling at the meagre grass. If they do look up and spot you, they adopt a proud posture to show off their horns, before trotting away. Until the 1950s, more than a million wild yaks lived in Tibet. Hunting has reduced that number to fewer than 15,000. On these high plains, cloudless nights are cold, but when the sun rises, temperatures can increase by as much as 27⁰C (49⁰F). Thin air and bright skies mean exposed skin burns easily. Black hair protects the yaks from intense solar radiation, though a few rare golden-coloured wild yaks do exist. Supremely adapted to the harsh, high – altitude conditions, yaks are the highest – living large mammals in the world. Compared with cows of the same size, wild yaks have larger lungs and hearts, and their blood is capable of transporting more oxygen. Their thick fleece, which is coated with frost in winter, keeps out the incessant Tibetan wind and freezing temperatures – as low as -40⁰C (-40⁰F). Black – lipped pikas are equally hardy, living at the same altitude as yaks, at around 6000m (19,700 feet). Relatives of rabbits, these small grass – eaters look like a cross between a guinea pig and a mouse and are known locally as Himalayan mouse – hares. They live at incredibly high densities – up to 300 in an area the size of a football pitch – but spend much of their lives underground. If you sit quietly among the many holes that pepper the plateau, you will eventually see them emerge. Pikas stay close to their burrows, squatting with their fur fluffed up against the bitter cold. If you make a move, the ground seems to come alive as hundreds rush for safety. Pika families use their burrows to shelter from the elements and from predators, but unlike other small mammals in harsh environments, they do not hibernate but somehow manage to store enough food to remain active all year. The robust pika is fundamental to life on the high plains. In this treeless environment their burrows provide homes for lizards and various nesting birds such as snow finches and Tibetan ground – tits. Predators on the plateau – wolves, snow leopards, buzzards and foxes – all feed on pikas. One of the most surprising pika predators is the Tibetan brown bear. Thought to be the inspiration behind the legendary Yeti, just a few remnant populations are scattered in the mountains around the plateau, and their habits remain a mystery. Though Tibet itself is dry, its enormous presence and position exert a huge influence on the rainfall and rivers across Asia. In the summer, the sun warms the massive flat expense of Tibet, and the plateau heats up like a giant hotplate. As the warm air rises, humid air is drawn in from the Indian Ocean to the south. Clouds build, and as they hit the Himalayas, monsoon rains fall over the foothills and the Gangetic Plains to the south. On exceptional occasions, the Tibetan plateau receives snow in the summer. If this happens the white blanket reflects the sun and the plateau takes longer to heat up, delaying the onset of the monsoon rains. And being the “roof of the world”, all the major Asian rivers – the Ganges, Brahamaputra, Yellow, Indus, Irrawaddy and Yangtze – begin their safaris in Tibet. Together they provide water for nearly half the world’s population.
WHERE THE GRASS IS GREENER
Follow the Brahamaputra off the Tibetan plateau, and it will lead you out onto the plains of India. When the Tibetan plateau was formed on one side of the Himalayas, the Gangetic Plain was born on the other. It is a large depression that, over millions of years, has filled with sediment washed down from the mountains. In places it is thought to be 13km (8 miles) thick. Monsoon rains drench this region every year, making it lush and green and one of the most productive plains in the world. Keep following the Brahamaputra, and you will eventually end up in northern India, in KAZIRANGA NATIONAL PARK in Assam. This is home to one of the highest concentrations of tigers in the world, possibly about 90, though you are unlikely to see them because the grass grows to more than 5m (16 feet) high in some places. The animals that you can sometimes see above the grass are the jumbo – sized herbivores – wild buffalo (1400), elephants (1000) and greater one – horned rhino (1600), which look like armour – plated versions of their African cousins. Just up the road from KAZIRANGA is MANAS NATIONAL PARK. Like Kaziranga, Manas is dominated by luxuriant long grass and is home to a much smaller plains resident – the rarest and smallest wild pig in the world – the pygmy hog. It uses the long grass to construct a thatched nest, which keeps the rain off during the monsoon, provides shade on hot days and can be a nursery for up to ten piglets, each small enough to sit in your hand.
AFRICA’S GREAT SAVANNAH
East Africa is often portrayed as an endless plain filled with hordes of grazing animals. For once the cliché is true. The largest of all the Great Plains are found here. Starting at the southern limits of the Sahara, these tropical grasslands form a huge arc that spans from the Atlantic coast in the west to the Indian Ocean in the east. From here they sweep down to the southern tip of Africa, together covering a third of the continent. These vast savannahs are highly productive and support some of the greatest concentrations of large animals.
During the annual migrations in East Africa, 200,000 zebras and 400,000 Thomson’s gazelles trek across the plains along with more than 1.5 million wildebeest. Africa’s grasslands are not only highly productive, but they also support the greatest variety of wildlife of all the Great Plains, including around 100 species of grazers. The diversity is the result of a mosaic of habitats – from the treeless plains of Serengeti to the acacia – wooded grassland of the Ngorongoro Crater. The unifying theme is grass – some as tall as an elephant, some that could only conceal an ant. Drive across Africa through this remarkable patchwork and exactly which type of savannah scenery you can expect to see will depend on a history of complex interactions among the plants, the animals and the elements. Fire, soil type, rainfall and the contours of the landscape are all important in shaping the different savannah backdrops. Each habitat hosts a different set of characters, from the sinuous gerenuk in the wooded savannah to the lolloping topi on the open plains, each adapted to fill one of many niches.
RECYCLING ON THE SAVANNAH
With numerous animals come heaps of dung. But the savannah is a dynamic place, and nutrients are recycled rapidly. Even before the dung has cooled, male dung beetles may have flown in, worked the waste into manageable balls, rolled them away and presented them to the females to lay their eggs in. The beetles bury the balls as deep as a metre (three feet or so) underground, providing a ready meal for their larvae when they hatch out. In the Serengeti, three quarters of all animal dung is dispatched by beetles, which fertilize the soil in the process. A brisk turnover on the savannah ensures that these Great Plains can continue to support large numbers of grazers year after year. The most numerous and perhaps the most influential grazers are largely unseen – the TERMITES. There are literally billions of them in vast underground colonies, and it is thought that termites take more materials from the plains of Africa than all the large grazers combined. Grass may be readily available, but it is difficult to digest. Both termites and large grazers use microorganisms such as bacteria and fungi in their guts to break down the tough parts. Microbes within a termite colony, which include gardens of fungi nurtured in special air – conditioned “rooms” are believed to equal the weight of the termites found there, which can amount to up to 7 million in a colony. Above ground, the larger grass – eating mammals in turn support meat –eaters such as lions, leopards and hyenas. And cleaning up after them are the scavengers, including jackals and vultures.
RAIN AND DROUGHT
Spanning the equator, the African plains do not have the temperature changes of the tundra, but seasonal variation is just as dramatic. Where the tundra and prairie have summer and winter, the African savannah has wet and dry seasons. For much of the year the savannah is baked hard. But after heavy rain, the parched earth becomes lush, green grassland in just days. Tropical sunshine and seasonal rains provide readily available and renewable food for millions upon millions of grazers, from the petite dik-dik antelope to the colossal elephant. Close on their heels comes an impressive array of plains predators, from lions and cheetahs to wild dogs and hyenas. African savannahs are fantastically prolific – able to support more than 200 times the mass of animal life compared to a rainforest of equivalent size. But the tropical lifestyle is also one of feast and famine. The timing and quantity of rainfall is unpredictable, and drought is common. If it does rain, the annual supply may pour down within just a few weeks. Sometimes the ground is so baked or the rains falls so hard that most of the water pours off the surface. Intense tropical sunshine evaporates up to 80 per cent of the downpour, and what moisture does remain may have to sustain life on the plains for the rest of the year. Animal and plant life on the savannah must be able to react to the whims of the weather. Grass can remain dormant until favourable conditions return, but the animals reliant on grass must migrate. It is these annual cycles of wet and dry that drive the great African migrations.
PREDATOR AND PREY
Sometimes, individual groups of animals adapt to very specific conditions. Across most of Africa, lions and elephants tend to steer clear of one another, but around a few waterholes in Chobe National Park in northern Botswana, circumstances are different. Under cover of night, lions hunt elephants. During the dry season it may not rain for eight months, and temperatures reach a debilitating 50°C (122°F). By October, the plains are a dust bowl. Elephants can only go for a few days without a drink, and during the driest months, tens of thousands stream across the dry hinterland towards areas of permanent water such as the Chobe River and the Okavango swamps. Thousands of elephant convoys, up to a hundred strong, follow the same pathways – wave after wave. Repeated pounding of feet engrave deep furrows across the landscape – northern Botswana is home to 130,000 elephants, a quarter of the world’s population. Through dust storms and stifling heat, 6 ton adults, tiny, week – old babies and all sizes between march up to 80km (50 miles) in a day on their way to water. In one area of Chobe National Park there is a cluster of small waterholes that elephants frequent – a pit – stop on the way to distant rivers. As they arrive at the waterholes, they bump and jostle against each other to squeeze into a space where they can drink. On the fringe of this boisterous gathering sits a pride of lions. If they need a drink, they must run the gauntlet of the herds and creep around at the elephant’s feet. Repeatedly the lions are chased off – adult elephants charge and kick up dust, scattering the pride with a wave of their trunks. Eventually the lions manage to take a drink. Finding food can be even more difficult – the wildebeest, zebra and buffalo that live here in the wet season left long ago. Night falls, and a cool breeze diffuses the tension. All seems peaceful. As the elephants drink, you can hear their rhythmic sloshing and gurgling and the rasping sounds of them rubbing their thick, hairy skins against each other. They rumble greetings to the herds that continue to arrive at the water throughout darkness. In particular, breeding herds with young ones seem to prefer travelling during the cool of the night. After sunset, lions are more comfortable, more confident and more alert. The balance of power has changed. The pride here is uncommonly large. In Africa, lions usually live in groups of no more than about 10 – 12 adults. At this waterhole, the pride is at least 30 strong, and at times there can be as many as 50 individuals. In the darkness, they take up position, fanning out across the well-worn elephant trails between two of the small waterholes. They make no attempt to get out of the way of the elephant traffic. It looks like an ill – prepared ambush. Lying draped across the cool sand, two or three of the females scrutinize the procession of herds. Sitting quietly in a vehicle among the lions, you can feel the tension. You notice elephants stumbling into the pride by accident. In the dark, they seem clumsier, perhaps because their eyesight is not as good as the lions. Big bull elephants and large breeding herds are ignored. They seem too strong and well defended to interest the lions. Occasionally, one or two recently weaned individuals pass the lions. Not yet fully grown, they are 2 – 3m (6 – 10 feet) at the shoulder and are travelling separately from the other herds. As they wander close to the pride, all the lions jump up. Elephants trumpet in alarm. Lions roar excitedly. The African night erupts. As a young elephant runs away, a chaotic pursuit begins. Thirty big cats are on its heels. One lioness leaps at its rear end, biting and clawing. Others join in until the sheer number of lions overwhelms the elephant and brings it to its knees. It may take 20- 30 minutes to die. Lions normally hunt smaller prey such as wildebeest and zebra, though in some parts of Africa, they will take baby or injured elephants opportunistically. At this waterhole, though, in the absence of more normal prey, lions seem to have worked out a successful strategy for overpowering adolescent elephants. A large pride is necessary to undertake such risky attacks. Some lionesses are injured in the chase, and some elephants do manage to escape by wheeling around and throwing their pursuers off. Others are helped by their mothers. If nearby, a mother will try to thrash the lions off with her trunk and her tusks. From observations over six weeks, about one in four attempts are successful. A large pride of lions can devour an elephant in less than two days. Sometimes they kill on consecutive nights, before they have even finished eating one animal, and through the dry season, they may kill as many as 30 or 40 elephants.
LIFE UNDER THE OPEN PLAINS.
One of the greatest challenges to animals living on the open plains is the lack of shelter. With so few trees, there is little shade from the sun and wind and few places to hide from the predators. Many mammals live below ground, and as a result, some plains can look devoid of life at the first sight. Nowhere is this more evident than on the Mongolian steppes. You can drive for mile after empty mile and not see a single animal. But beneath the soil are numerous small burrowing mammals, including marmots, hamsters and gerbils and even a burrow – dwelling cat, Pallas’s cat. Burrowing beasts are common across all the Great Plains – pikas in Tibet, lemmings in the tundra, viscachas in South America and ground squirrels in America. The biggest burrows are those of the aardvark. An aardvark can dig a 10 – m (33 – foot) long burrows with an entrance hole almost large enough for a person to crawl in. Among the most extensive burrows are those of the prairie dogs on the North American plains. These rodents live in gigantic colonies – “towns” – containing millions of residents and extending over vast areas. Sometimes disused prairie dog holes are taken over by burrowing owls. In the absence of trees on the prairie, they may choose to nest in burrows. The burrowing owl has another ingenious trick. In some areas, a male will place bison and cattle dung outside the burrow, which attracts dung beetles that they then eat.
STRENGTH IN SPEED AND NUMBERS
In these large, flat, open landscapes, running is a good strategy for both predators and prey, and so it is not surprising that plains animals are among the fastest in the world. In Africa, the cheetah has been recorded at 103kph (64mph) and the ostrich at 72kph (45mph). In America, the pronghorn antelope has been recorded running at up to 88.5kph (55mph) for 0.8km (half a mile) and can cruise at 67kph (42mph) for more than 1.6km (a mile). Grazing animals that cannot escape underground tend to live in large herds for protection – up to 100,000 individuals, in the case of the Mongolian gazelles. More animals mean more eyes to look out for predators such as wolves. Female Mongolian gazelles, like the snow geese, caribou, wildebeest and many other plains animals, also have a highly synchronized calving season – they nearly all give birth during one week in June. If an area is swamped with calves for a few days, predators can kill only a fraction of the newborns before the rest are old enough to run away. From the Arctic tundra and the Tibetan plateau to the tropical savannahs of Africa, impressive herds gather on the Great Plains to raise their young. Together they form the greatest aggregations of wildlife on the Planet Earth.
