Words by George Monbiot
Beavers bring life to rivers and the land.
They re-engineer the landscape to create safe habitats for themselves, where they can hide from predators and swim to where their food grows.
Beavers feed on bark and leaves in the late autumn or winter, then switch to softer wetland plants in the spring and summer.
They never travel far from water.
Life is easy for the beavers that live on big rivers. But when the best habitats are fully occupied, young beavers are forced away from them through vicious territorial disputes, and must make their homes along the narrow tributaries. Here they are more vulnerable to predators. So, millions of years ago, to avoid the big cats that preyed on them, they learnt to build dams. In doing so they radically changed the habitats in which they live.
Using stones, branches and mud with astonishing ingenuity, they construct first one and then a series of small dams. Wherever they find a leak, they stop it up. Before long, even small seasonal streams start to look like mountain rice paddies dammed up with wood: a series of stepped pools, surrounded by wetlands.
These are phenomenally rich habitats, that abound with life: harbouring an abundance of insects, and great concentrations of frogs, small mammals and waterbirds.
Beaver dams also regulate floods and droughts, cleanse the water of sediments, filter out poisons and recharge groundwater.
North American tribes revered the beaver. They knew that the landscapes beavers created are the ‘earths kidneys’, purifying water and regulating its flow. They noticed that beavers are highly social creatures who live in their lodges built of sticks in tight family groups. They saw that the adults go to great lengths to care for their offspring.
Aunts and uncles from earlier litters look after the youngest kits. They carry them away from danger, clasped to their chests with their front paws. They warn them of aquatic predators by slapping their tails on the water. They bring green food to the kits, when they are too small to leave their lodge. They cuddle them and call gently to them. For these reasons, Native Americans called them the ‘little people.’
In the late 1600s the Europeans came. For them, beavers represented something quite different: commercial value. Europe’s beavers, that once numbered in the tens of millions, had been almost eliminated because of the value of their scent glands. Beavers’ scent glads contain castoreum: a compound that’s rich in salicylic acid, from the willow bark the animals eat. This is a powerful pain killer. The combination of this valuable compound, the beaver’s fine fur and tasty meat ensured that one animal was worth as much as an entire year’s earnings for a medieval peasant.
While castoreum from American beavers was less valuable, as they ate more cottonwood than willow, their soft, thick pelts put a high price on their backs. Demand was insatiable. In particular, people wanted their fur for hats. Beaver hats made from felted underfur were water roof and durable. Trappers fanned out across the new world, scouring its wetlands for valuable pelts. By the time the geographers, map makers, photographers and settlers arrived in their footsteps, the beavers were long gone.
As the beavers disappeared, the water went with them. Rich ecosystems, especially in the southern states, dried up and vanished. Hunting grounds and fisheries collapsed. Forest fires raged through the shrivelled vegetation around the dried-out creeks. The range lands downstream turned brown. Cattle jostled to drink from the last of the old beaver ponds.
Eradicating beavers was a terrible mistake, causing harm that cascaded through our living systems.
But by bringing back the little people to the depleted lands of Europe and North America, we can restore our rivers and wetlands, recharge our groundwater, stop floods and droughts, and witness once more the abundance of wildlife that accompanies beavers, wherever they make their homes.