IELTS Academic Reading Practice Test 500

What animal is bold enough to raid a bees' nest, kill a cobra and, if a lion interferes, stand its ground? The honey badger, a stocky carnivore found across much of Africa and southern Asia, has a reputation for fearlessness that is unusual among mammals of its size. Its scientific name, Mellivora capensis, means 'honey-eating animal of the Cape' and refers to its fondness for the contents of beehives rather than to any close relationship with badgers. The species is in fact the only member of its subfamily within the weasel family. Afrikaner settlers called it the ratel.

The honey badger's range is exceptionally wide for a carnivore of its size. It occurs almost everywhere in sub-Saharan Africa, from the edges of deserts to dense woodland, and the range continues through the Arabian Peninsula into Iran, Central Asia and the Indian subcontinent. It is absent only from the wettest rainforests and from the far north of Africa. Within this vast area it is nowhere common: the animals live at low densities, are largely solitary and travel long distances, so that even experienced fieldworkers may go months without seeing one. Radio-tracking has shown that an individual may range over hundreds of square kilometres.

Physically, the honey badger is built for confrontation rather than speed. Adults measure perhaps 60 to 75 centimetres from nose to the base of the tail, and males, which are noticeably larger than females, may weigh 12 kilograms or more. The front legs carry curved claws several centimetres long, powerful digging tools that also allow the animal to break into termite mounds or climb trees. The skin is exceptionally thick and, crucially, loosely attached to the body, so that if a predator seizes the animal by the neck it can turn inside its own hide and bite back. The claws cannot be retracted.

The species is often described as a generalist, which is a polite way of saying that it eats almost anything it can overpower. Insects, scorpions and other invertebrates form a large part of the diet; birds, rodents, lizards, frogs, tortoise eggs and carrion are taken when available, and fruit is eaten seasonally. Much of its food is excavated rather than chased. The molar teeth are flattened and adapted to crushing, which allows the animal to deal with hard-shelled prey such as beetles and tortoises.

Bees' nests are a particular prize, and it is the habit of breaking into them that gave the species both its common and its scientific name. The animal tears an opening in the nest or in a tree trunk with its front claws and feeds on honey, larvae and wax, apparently indifferent to a defence that would drive off most mammals. The thick skin and coarse hair are usually said to protect it from stings. Hives suspended from branches are also visited, and beekeepers in several African countries regard the species as a serious pest because of the damage it does.

Venomous snakes, including cobras and puff adders, are among the more surprising items on the menu. The honey badger attacks with a rapid grab at the head or body, and a struggle can continue for an hour or more. In some parts of its range the animal is said to survive a bite that would kill a dog, and a degree of tolerance to venom has been demonstrated, though it is not complete and the mechanism is not fully understood. Reports of immunity should therefore be treated with caution: honey badgers are resistant, not invulnerable, and an animal bitten several times may sicken or die.

Few predators trouble an adult honey badger. When threatened it raises its tail, utters a loud growl and rushes at its attacker, and there are well-attested accounts of the animals driving leopards and lions away from kills. Because it is small and scarce, the species is not important prey for any large carnivore. An anal gland produces a foul-smelling secretion, which is thought to serve as a warning, although this has been studied far less than the equivalent defence in skunks.

The animal's intelligence is attested mainly by anecdote, but some of the anecdotes are striking. Captive individuals are notorious for escaping from enclosures and for solving problems that their keepers did not expect them to notice. In one recorded case, a honey badger at a rehabilitation centre in South Africa was seen using a stick to reach food that was otherwise out of reach, and the use of objects as tools has since been reported in other captive animals. Whether such behaviour occurs in the wild, where the animal must find food rather than escape from a cage, remains unknown.

Breeding is seasonal in the north of the range and more continuous in the tropics. After a gestation period of about two months the female gives birth to a single cub, which is born blind and almost hairless and stays with its mother for perhaps a year and a half.

The International Union for Conservation of Nature lists the honey badger as a species of least concern, since it occupies an enormous area with no evidence of rapid decline. One further claim deserves caution. A popular story holds that a small bird, the greater honeyguide, lures the honey badger to bees' nests and shares the spoils. The bird certainly guides human honey hunters in parts of Africa, but the partnership with honey badgers rests on very little evidence.

Mountains are the most conspicuous evidence that the Earth's surface is never still. Most ranges are the product of enormous forces acting over tens of millions of years, and they are also, on a geological timescale, temporary features: the higher a mountain stands, the more vigorously the weather attacks it. Understanding how mountains are formed therefore means understanding not only how the crust is pushed up but also why the uplift continues, and why some ancient ranges survive as high ground long after the forces that built them have died away.

The framework for answering these questions is plate tectonics. The Earth's outer shell is broken into a dozen or so large plates, together with many smaller ones, which drift across the underlying mantle at a few centimetres a year, roughly the rate at which fingernails grow. Mountains are built mainly where plates meet. Where one plate dives beneath another, the process called subduction, the result is a chain of volcanoes and folds above the descending slab. Where two continents collide, the crust is thickened and a great range is raised.

The Andes provide a textbook example of the first. Off the west coast of South America, the dense oceanic plate of the Pacific floor bends down beneath the lighter continental plate and sinks into the mantle. As the descending slab heats up, it releases water that lowers the melting point of the rock above, generating magma that rises to the surface and builds volcanic peaks. At the same time, sediment and crust scraped from the ocean floor are compressed and folded against the continent's edge, adding a belt of ridges. The combination of volcanism and folding has produced a range that runs for some 7,000 kilometres.

The Himalayas, by contrast, are the product of a collision. Some fifty million years ago the Indian plate, moving northwards, met the Eurasian plate. Neither would sink, because both carry thick, relatively light continental crust. Instead the rocks were crumpled, thrust over one another and thickened, so that the range now stands more than eight kilometres above sea level at its highest point. India has continued to move north, and the range continues to rise by a few millimetres a year. The pressure is transmitted far into Asia, raising the high plateau of Tibet and pushing up ranges thousands of kilometres to the north.

Not every mountain is a pile of folded rock. Many are volcanoes, built up by successive eruptions of lava and ash. Subduction zones produce chains of these, but there are also volcanoes far from any plate boundary, over places where a column of unusually hot rock, called a mantle plume, appears to rise from deep within the Earth. The Hawaiian islands are the best-known example; the plate drifts over the plume, and each new island is built as the old ones are carried away. The biggest range on the planet is also the least visible, lying beneath the oceans where the crust is pulled apart.

Some ranges are neither volcanic nor notably folded. Where the crust is stretched by the pulling apart of plates, it breaks into blocks separated by steep faults. As the blocks move, some are lifted and others drop, producing the pattern known as fault-block mountains. The Basin and Range province of the western United States, a landscape of long parallel ridges separated by flat valleys, is a familiar example, as is the East African Rift. The Sierra Nevada of California is a tilted block of granite, raised along a fault on its eastern side.

Why do mountains stand so high in the first place? In the 1850s, gravity surveys in India produced measurements that could not be explained by the visible mass of the Himalayas alone, and two British scientists, George Airy and John Pratt, offered rival explanations. Both are forms of the idea now called isostasy.

Airy suggested that a range has a deep root of comparatively light crust projecting into the denser mantle, in the way that a block of wood floats deeper in water than a thinner block of the same material. Pratt proposed instead that the mountain is supported by rock of lower density beneath it. Modern measurements suggest that both effects occur.

Uplift and erosion are locked together. The higher a range becomes, the more rain it intercepts and the steeper the rivers that cut into it. Rapid erosion removes mass from the top of the range, which allows the hot rock beneath to flow upwards and the mountains to rise further. In some places this feedback may help to shape the range itself: the deep gorges of the Himalaya appear to coincide with zones of unusually rapid uplift. In the very long run, however, erosion wins. The Appalachians of eastern North America were raised by a collision hundreds of millions of years ago and have since been worn down to rounded, forested ridges.

Many questions remain open. Geologists can measure present-day movement with the Global Positioning System, but the behaviour of the mantle beneath a growing range is hidden from direct view and must be inferred. Why subduction begins at a particular place, and why some collisions produce plateaus rather than narrow chains, are still contested. What is clear is that the mountains we see are snapshots. The summit of Everest, formed from marine limestone, contains the fossil remains of creatures that lived on a shallow sea floor, and the rock has been raised more than eight kilometres since then.

The argument over how to measure work is as old as employment itself, but it has acquired new urgency. For most of the industrial era the answer was hours, and that answer was a hard-won reform rather than a bureaucratic convenience. Campaigners who demanded a ten-hour day, and later an eight-hour day, were trying to place a limit on the demands an employer could make. The slogan of eight hours for work, eight for rest and eight for whatever else a person chose, attributed to the Welsh reformer Robert Owen, expressed a claim about human life rather than about productivity. Paying for time also had the virtue of being simple: a clock and a rate of pay settled the matter.

The rival principle, payment for what is produced, is equally old. Farm labourers were paid by the harvest, weavers by the piece, and sailors by a share of the catch. Piece rates spread through manufacturing in the twentieth century, and commissions through sales. The case for such arrangements is straightforward. They transfer the risk of slow work to the worker, they reward effort directly, and they make supervision unnecessary. Where the unit of output is well defined, a garment, a delivery, a sale, they can work well for both sides, and many self-employed people still prefer them.

The difficulty begins when the unit of output is not well defined. Most professional work is like this. A surgeon operates as part of a team whose results depend on the anaesthetist, the nurses and the equipment; a lawyer's letter draws on years of training and a library built by others; a manager's contribution may only become apparent years later, and may consist of preventing something from happening. Output is often produced jointly, observed indirectly and felt long after the work is done. To measure it, organisations must invent proxies, and the proxies are rarely the thing that matters.

There is a further problem, neatly captured by a rule of thumb in economics known as Goodhart's law, which holds that once a measure is adopted as a target, it tends to stop being a useful measure. People respond to what is counted. Software developers have been paid by lines of code and have written longer programs; academics are judged by the number of papers they publish and produce more, in smaller pieces; call-centre staff are timed on the length of calls and end them sooner. None of these behaviours is dishonest, and all of them are rational. The measure has simply done what measures do: it has redirected attention.

Hours, however, are no better. Time at a desk is a poor guide to work done, as anyone who has sat through a long meeting will confirm. In many offices, long hours function as a signal of commitment rather than a record of achievement, and the result is presenteeism: people staying late because leaving early would be noticed. When offices closed in 2020 and staff worked from home, the fear that output would collapse proved unfounded in many organisations, and it became harder to pretend that visible presence and useful work were the same thing.

The most radical response has been to abandon schedules altogether. Over the past two decades a number of firms, encouraged by management consultants, have experimented with arrangements in which employees are assessed only on whether agreed results are delivered, and may organise their days as they wish. Reports from such firms are often enthusiastic, and it is easy to see why: staff who can collect a child from school or work when they are freshest are likely to be more content. But these experiments are rarely subjected to independent evaluation, and the firms that publicise them tend to be those that found them successful.

Output-based systems also distribute risk unevenly. A worker paid by the task bears the cost of quiet periods, illness and equipment failure, which is why the spread of piece-rate work in parts of the gig economy has attracted criticism. Where output is paid for without any floor, the pressure to work faster and longer is intense, and safety and quality are the first casualties. It is no accident that industries with grim records on industrial injury have often been those paid by results.

Nor do output measures capture much of what makes an organisation work. Mentoring a new colleague, maintaining equipment properly, documenting a process so that others can follow it, keeping a dangerous procedure slow and careful: all of these consume time and produce nothing that can be counted, and all can be quietly dropped when only countable things are rewarded. A hospital that measures the number of operations performed may find that the operations become simpler.

My own view is that the choice between hours and output is a false one. Where output can be defined honestly, and where the quality of the work can be judged by someone competent to judge it, people should be assessed on what they achieve, not on how long they sat at a desk. But this is not an argument for abolishing limits on working time. Hours are a poor measure of contribution and a good defence against exploitation, and the two roles should not be confused. The sensible arrangement is to measure results while continuing to restrict the hours in which they must be delivered.