Wednesday, March 20

Beavering away again


WE all ‘beaver away’ at work to earn our living.
The English word ‘beaver’ is derived from Old English ‘beofor.
When the word beaver is mentioned, our minds tend to focus on the well-documented Canadian beaver (Castor Canadensis) and forget there is a Eurasian species (Castor fiber). This latter species, since 2000, is gradually being reintroduced into selected sites in the UK.

Eurasian beavers
These are Europe’s largest native rodents which frequently feature in the British Isles, sometimes for the wrong reasons.
Ill-informed people even suggest that the demise of trout and salmon in British streams and rivers is due to beavers.
This is total poppycock, for beavers are vegetarians! Others maintain that, because of the beavers’ propensity for building dams, they cause flooding.
Again, this is far from the truth as beavers are not appreciated for their environmental achievements in the countryside.
In the mid-tenth century, they were recorded in Welsh history and again in 1188, although in earlier Anglo-Saxon times, their numbers had already begun to decline as they were hunted for their pelts.
Hunting gradually decimated their numbers right through
to the 16th century when they became extinct in Britain. However, large populations survived in remoter areas of Scandinavia and in Eastern European countries and it is from the latter regions that colonies are now being reintroduced to the British Isles.

Distinctive characteristics
These creatures are superb swimmers and divers, staying underwater for 15 minutes at a time. Their webbed hind feet and long scaly, paddle-like tail propel them at quite high speeds but their movements on land are rather more laboured.
When wet, their beige or pale brown coat looks spikey.
Their small black ears and eyes, together with four prominent incisor teeth, resemble guinea pigs.
However, they have relatively poor eyesight and rely very much upon their senses of smell and hearing. Their distinctive teeth are regularly honed by their constant gnawing of wood and thus continuously grow throughout their life span of 20 to 25 years.
Unlike other mammals, beavers’ teeth are resistant to acids, their sharpness being due to the iron content of the enamel.
Monogamous by nature, adult beavers can weigh up to 25 kilogrammes and both male and female take a significant part in rearing their young, known as ‘kits’, which can number from six to eight in a birth cycle.
After one or two years in their parents’ ‘lodge’, the young beavers make their own way in life, building their own lodges nearby.

Beavers’ lodges are their castles
Their homes are created from gnawed-down branches and twigs of nearby trees which are interwoven and then plastered over with mud.
Each lodge has an underwater entrance into a wet chamber where the beaver dries out before entering the family’s drier room.
Most lodges are annually repaired by nocturnal working in the late summer months with the beavers cutting down, lifting and carrying wood in their teeth and dragging river mud and stones with their forepaws.
This concerted effort probably led to the phrase ‘working like beavers.’ Usually their lodges are located upstream of their dams, with a pond providing absolute privacy.

Dams and ponds
Beavers are no fools in exploiting river blockages of already fallen trees across a river bed. Tree roots that have been exposed by the erosion of riverbanks during previous flash flood events have been undermined and, thus, collapsed into the river.
In a river only 1 kilometre from my house, where riverbank trees have collapsed into a river, a colony of beavers have exploited this situation by adding stones and twigs in their dam building.
These Eurasian beavers have not felled these trees themselves, unlike their Canadian counterparts. Undoubtedly, beavers are environmental entrepreneurs!

Territorial rights
Beavers, like most animals, mark their territories, in their case, through urinating in a most distinctive, odorous fashion.
Unlike most mammals, their urine content contains the much acclaimed medicinal property of ‘castoreum.’
This chemical is emitted from castor sacs near the beaver’s tail. Their urinating spots are not unlike our walls and fences we may have in our gardens to demarcate the ownership our land.
These ‘spots’ are distinguished by small piles of stones and mud which are strategically located around their territorial defensive sites. Like us, they do not value unwanted invaders.

Reintroduction to Britain
Conservationists, naturalists and river anglers have welcomed these vegetarian mammals back into British rivers. Yet, still, a myth persists amongst some farmers and river fishing-rights owners that they are invasive animals.
The first colony of Eurasian beavers was introduced at Ham Fen in the county of Kent in Southeast England in 2001, and 2002 saw another colony on the River Tay in Scotland.
In 2005, a third colony was established in the Forest of Dean, Gloucestershire, in West England. A year later, they appeared at Martin Mere, a wetland site, north of Liverpool.
The beavers on The River Otter in Devon, Southwest England, are thriving and have become a tourist attraction in summertime!
This year, a colony has been introduced in the North York Moors National Park in the hope that, through their dam-building and ponding of water, their efforts will control flash floodwaters off the moorlands, which over the more recent years have inundated people’s houses downstream.
The UK government, through its rural and environmental agencies, has given conservationists full support in reintroducing native Eurasian beavers to their once natural habitats.

Ecosystem system changers
These mammals have been found to create cleaner water in rivers and boost the numbers of other forms of wildlife in their patches, to include wild plants.
With ever-increasing intensive rainfall inputs in Europe and elsewhere attributed to climate change, beavers can provide a valuable purpose through their constructions of dams.
These dams, and the ponds behind them, hold up river and stream discharges, gradually releasing the water downstream. Flash flood episodes could now be a thing of the past, with less flooding of villages and towns downstream.
The wild beaver colony in Devon has constructed 13 dams, thereby increasing the River Otter’s previous storage capacity from a couple of hundred litres of water to tens of thousands of litres in the ponds they have created!
Little do beavers realise that their activities actually protect humans from potential flood disasters which they have managed to avert. They, no doubt, are more sensitive than us to reading changes in our climate and the resultant extreme weather patterns that seem to increasingly occur.
Whilst Castor fiber is known as the Eurasian beaver, my knowledge of the ‘Eur’ beaver is relatively up to date but, sadly, I know absolutely nothing about the ‘Asian’ beaver which appears in northern parts of Asia.
Do beavers exist in South East Asia and particularly in West and East Malaysia? I would love to know