Page 25 - BBC Wildlife Volume 36 #02

BRITISH BEAVERS

“ BEAVERS COULD
BE NATURAL ALLIES

AS WE TRY TO TURN
THE TIDE ON MAN-

MADE PROBLEMS.”

many environmental ills they may help cure are flooding, Above: beavers are Armed with powerful jaws and impressive, chisel-
soil erosion, habitat and species loss, agricultural run- nocturnal and favour like incisors, they do this by felling trees whose trunks
the bark of aspen,
off entering waterways and freshwater pollution more are driven vertically to create the initial framework of
hazel, birch, alder and
generally. Not bad for a bunch of rodents. willow (pictured). The the dam. The beavers work quickly and methodically to
Beavers are semi-aquatic mammals that need deep, still rodents store food in reinforce the structure with small branches, twigs, rocks
water to feel safe from predators and raise their young. If underwater piles to and even mud that they knead into the smallest gaps.
sustain them through
there is no suitable habitat in the area, they simply engineer
there is The slightest sound of trickling water sends them into a
the winter months.
it themselves. Thousands of years of evolution have seen flurry of activity as they locate and plug up any leaks.
it thems
to it that The result is a quiet, still beaver pond in which
to it that beavers will compulsively dam up fast flowing
streams they can build their lodge. At first glance, it looks
streams if no agreeably deep water is available.
like a chaotic tangle of branches and twigs, but
there is method in the ‘madness’. The structure is
like a thatched mesh, laced with a muddy paste to
strengthen it. An underwater entrance, which can
be accessed only by the beavers, is the final line of
defence from predators and the elements. Once
they’re safely inside, the snug lodge provides shelter
through the winter and a place to have kits.
At one time the Eurasian beaver, along with its
North American counterpart Castor canadensis, was
widespread across much of the Northern Hemisphere.
Numbering in the millions, beavers had a huge
impact, buffering the flow of water and nutrients
through the landscape and keeping aquatic systems
stable and healthy. But the animals were valued instead
LO CANALS for their fur and castoreum, an anal secretion that you
LODGE
e
Beavers sometimes prefer to These narrow channels are cut into
B
might be surprised to learn was – and still is – used
use natural holes or burrow into
us e the riverbank to connect several
as a vanilla flavour enhancer. Demand fuelled a lively
banks. Elsewhere, including
ba different areas of beaver activity.
trapping industry that caused populations of both
wh
where the water is too fast- They are often used to transport
species to crash. In the British Isles, beavers were
moving, they build lodges from
m o food and building materials to
driven to extinction by the 1500s.
s sticks and branches. the dam or lodge.
t
i
Today the hope is that the Cornish Beaver Project will
mark another successful step towards a future where
BBC Wildlife 25