Beavers are large, semi aquatic rodents that live in the temperate climates of the world’s northern hemisphere (typically Canada, North America and Europe). Their official genus name is Castor and there are two species – the North American and the Eurasian (European). Both species are similar, although the Eurasian has a narrower tail and more triangular nose.
As Capybaras are the proud owners of the’ Biggest Rodent in the World’ title, beavers have to settle for a close second place on the size stakes. Indeed, they tip the scales at an impressive 24-66 lbs (11-30 kg) and are between 25-50 inches (0.8-1.2m) long – but if you think that’s a good size, then you should’ve seen them back in the ice age, when their ancestors were giants, growing up to 8ft (2.5m) and weighing up to 200 lbs (91kg) – yikes!
Beavers have large heads and rounded, stout bodies and of course those famous protruding, long incisor teeth. They can be grey or brown coloured and have small front paws and larger, webbed back feet, with an impressive, large, flat paddle tail. Their eyes and ears are arranged to allow them to almost fully submerse themselves in water, whilst just peeking the top of their heads out of the surface to keep an eye and ear out for what’s going on.
Beavers are herbivores and enjoy munching on bark and aquatic plants, including grasses. They live in freshwater environments such as rivers, streams, lakes and large ponds and of course trees feature significantly in their lives.
They are big players in the art of construction, skilfully creating impressive looking lodges, in which they live and building dams to divert the water flow. To achieve this, they fell trees – using nothing but their teeth! (You wouldn’t want to be on the wrong end of that gnawing gear!!). They move rocks, mud and vegetation to achieve the effect they desire, with their strong, streamlined bodies, making the task of towing the trunks and logs along in the water far easier.
Their dam construction helps conserve water and creates wetland habitats, which are home to many other species; also their felling of trees helps create ideal living conditions for various woodland dwellers – this has earnt them the status of a keystone species. That said, sometimes beavers can come into conflict with humans, where their water diversions are not so welcomed, for example, due to disrupting flood defences. Therefore, beaver management techniques are being employed to help smooth out any ruffled fur!
Beavers are old romantics at heart, forming monogamous pairs and living with their young as a family. Mating takes place in the winter, with up to 4 youngsters (kits) being born in the spring. The kits spend the first couple of months in the lodge, before venturing out to join their parents. Beaver families mark their territory with scent, enabling them to recognise and identify other beavers scent markings (and thus tolerate) neighbouring clans.
Did you know that Beavers produce castoreum from castor sacs (near to their tails)? This was a highly prized commodity and was once a reason that beavers were sadly hunted (as well as for their meat and fur). The castoreum was used in medicine, perfume and even as a food additive in the early part of the last century. Thankfully, it is now rarely used – and if it is, it must be harvested from a live beaver (who is mercifully anesthetised first) before having its castoreum sacs “milked”. This is rare and unpopular practice will hopefully soon cease completely.
It was demand for the castoreum, together with the popularity of beaver meat and pelts that led to their overhunting, bringing them to endangerment. However, more recent protection of the species has helped them to recover and there are now an estimated 6-12 million North American beavers and 1 million Eurasian beavers, with the good news being that they are no longer considered endangered.
Whilst once a native species to the UK, the beaver sadly became extinct here in the 1500s due to overhunting. However, they are being reintroduced and there are now over 400 of these critters gracing UK waterways once more.
Their fur, which of course if far better left on them, has a longer top cover, to help keep them warm and dry (further enhanced by the beaver’s own oily secretions) and a softer undercoat. They like to update their wardrobe with a regular summertime malting.
Beavers are fond of the wet stuff and their bodies are very well adapted to aquatic life – they have webbed feet that act as paddles, the ability to close off their nostrils, ears and even throats underwater, as well as special membranes to cover their eyes and that flat tail that acts as a rudder. They can also hold their breath for an awesome 15 minutes – yep, these guys are born hydrophiles. Although they are somewhat awkward on land, beavers are very graceful swimmers, achieving an impressive speed of 5 miles per hour.
As mentioned, they also have an impressive set of gnawing equipment – their incisors are tough, orange in colour (due to iron content) and grow continuously – it’s these remarkable dental features that allow them to chomp their way through trees with seeming ease.
Back to that tail, as well as functioning as a rudder in the water, it provides the beaver with stability and balance on land and has a neat trick of regulating body temperature via blood flow, providing some respite on a hot day, or a little extra warmth on those chilly evenings.
Beavers are smarty pants, with a relatively advanced brain, indicating high levels of intelligence, so they’ve got it all figured out…
They are good hosts, sometimes sharing their lodges with other creatures, such as muskrats, who in turn, help the beavers out by keeping underwater channels clear of weeds and warding off intruders, so a “you scratch my back, I’ll scratch yours” relationship all round.
The image of a beaver is the symbol of industriousness and enthusiasm – all admirable qualities (hence the sayings, “busy as a beaver”, “beavering away” and “eager beaver”). Maybe this encouraged the Canadians to adopt the beaver as their national animal (together with the fact the animals thrive in their territories) – a great choice as you’d have to agree that beavers are to be admired – eager, busy and smart – a winning combination!