IELTS Academic Reading – Practice Passage 4

Reading Passage

AFew animals have shaped the rivers of Europe as thoroughly as the beaver, and few have been missed so little while they were gone. For thousands of years these large, water-loving rodents were a familiar sight along waterways from Scotland to Siberia. Then, over several centuries, they were hunted relentlessly – for their thick fur, for their meat, and for castoreum, a substance produced by the animal that was once valued in medicine and perfume. By the start of the twentieth century the European beaver had been driven to the very edge of extinction, surviving only in a few scattered populations. In the last few decades, however, deliberate reintroductions and careful protection have allowed the beaver to return to rivers where it had not been seen for generations.

BWhat makes the beaver so remarkable is not simply that it has come back, but what it does once it arrives. Beavers are often described as “ecosystem engineers” because, more than almost any other animal, they physically rebuild the places where they live. Using their powerful teeth, they fell small trees and gather branches and mud to construct dams across streams. Behind each dam the water spreads out to form a pond, and a series of dams can turn a narrow, fast-flowing channel into a chain of pools and wetlands. The beavers do this to create the deep, still water in which they feel safe from predators – but the effects reach far beyond their own needs.

COne of the most valuable of those effects concerns the movement of water. A landscape dotted with beaver dams holds on to rainfall instead of letting it rush away. During heavy storms, the dams and ponds slow the flow and store large volumes of water, which can reduce the height of floods further downstream. In dry spells, the same stored water is released gradually, helping streams to keep flowing when they might otherwise shrink to a trickle. The ponds also trap silt and filter out some pollutants, so the water that eventually leaves a beaver wetland is often cleaner than the water that entered it.

DThe wetlands that beavers create are among the richest habitats in the countryside. Shallow, still water is ideal for frogs, toads and newts; the flooded margins attract dragonflies and countless other insects; and the mixture of open water, dead wood and fresh growth draws in fish, water birds and small mammals. Where beavers have returned, surveys have repeatedly recorded more species living along the river than before. In this way a single animal, simply by following its instincts, can raise the biodiversity of an entire valley.

EFor all these benefits, the beaver’s return has not been welcomed by everybody. Farmers and landowners point out, reasonably, that the animal does not distinguish between a wild stream and a valuable field. Dams can flood pasture and crops, block drainage ditches, and back water up onto roads; the trees that beavers gnaw down are not always ones their human neighbours were willing to lose. In places where beavers have spread quickly, these conflicts have become a serious practical problem, and they explain much of the resistance that reintroduction schemes still meet.

FTo weigh the gains against the costs, several countries have run carefully monitored trials rather than simply releasing the animals and hoping for the best. Scientists have tracked how beaver numbers grow, how the water around them changes, and how neighbouring farms are affected, gathering evidence over many years. The findings have generally been positive enough that, in a number of European countries, the beaver is now a protected species that may not be killed or disturbed without special permission. Protection, however, brings its own difficulties, since it limits what landowners are allowed to do when a dam appears in an inconvenient place.

GThe long-term future of the beaver will therefore depend less on the animal itself than on whether people can learn to live alongside it. A range of practical tools already exists: a pipe can be run through a dam to hold a pond at a level that does not flood nearby land, and trees of particular value can be wrapped to protect them. Managing beavers in this way costs money and effort, but it is usually far cheaper than the flood defences and water-treatment works that the animals can partly replace. For a creature that was almost wiped out, the beaver has become an unlikely test of whether modern societies are willing to share their landscapes with the wildlife they once removed.