all about beavers

am. d a eynolds, courtesy of Worth r Photo by Cheryl

A young beaver grooming itself.

Beavers have shaped this land more than any animal except for humans. They have teeth fortified with iron that grow about four feet per year. Their front paws have almost-thumbs to help them grasp and manipulate things and their back paws are webbed.

The more you learn about these incredible creatures the more amazing they become.

And then a pair decide to set up house near your home or cottage. Oh boy.

They will gnaw down trees as thick as 12 inches and can snip through trees under 5 inches in minutes. They build dams to flood an area that may include a road or part of your yard. The flooding will kill the trees in an area, leaving behind a graveyard of snags, stumps and water. And if you manage to trap the pair giving you trouble, a new pair will move in shortly. Take away the material they’re building into a dam and they’ll just rebuild after the sun goes down, again and again and again.

But you must have patience, dear landowner, because you will have to negotiate your space with the

aderot. Photo by d

The beaver’s teeth are so powerful that it can gnaw down a tree as thick 12 inches in minutes. beavers. You will have to accept that their “destruction” gives new life to an area. And if their building is truly unacceptable, you will need to contact your provincial ministry responsible for sustainable development or natural resources. The regulations are different in Alberta, Manitoba and Ontario. Keystone species

Beavers are a keystone species in Canada. They engineer environments around rivers and streams to suit their needs, drastically adjusting the flow of waterways and, in some cases, adding canals to get more trees to their lodges. They create wetlands.

Now, more wetlands may not be what you’re looking for. They aren’t conducive to much that humans do; you can’t even go for a walk in a wetland. But consider that almost half of the endangered and threatened species in Canada live in wetlands. This includes songbirds, waterfowl, fish and amphibians.

Beaver dams clean the water, too. By slowing the flow, more water seeps into the ground. The bottom of a beaver dam builds up bacteria that neutralizes pesticides and herbicides and also turns nitrates back into nitrogen gas, which returns it to the air.

Concerns about “beaver fever”, or giardiasis, should be allayed. Beavers are a vector for giardiasis, but so are humans, birds and cows.

Mating for life

Beavers mate for life and the young stay with the parents for two years, helping out through the birth of younger siblings. One litter of two to four or as many as six is born per year, usually in May or June.

The kits are born fully furred and with teeth, and their eyes open within a few hours, sometimes after being rubbed with their front paws. They may try out the water on their first day, but they stay in the lodge for up to five weeks.

Beaver lodge.

They will try to gnaw on wood at about 11 days old. By three weeks old, they are eating mostly vegetation, but they do continue to nurse until they are about eight weeks old. At three months of age, the kits can walk and carry construction material at the same time.

The beaver body

Beavers move pretty awkwardly on land, but in the water they are machines. They swim with their noses, eyes and ears above water but can survive for 15 minutes submerged. Their webbed hind paws help them swim and their flat, leathery tails help them steer.

These animals can see underwater because they have an extra set of eyelids that are clear. They have flaps in their noses and ears that close to keep out water and their mouths are adapted to move tree branches in their teeth without swallowing the river. Their fur is also adapted for their semi-aquatic lifestyle. The coarse outer fur, which they slick down with fatty secretions, keeps water from getting to their inner fur and skin.

The forepaws are nimble, helping beavers manipulate foodstuffs, construction material and their young. They don’t have thumbs, but they will carry mud and stones between their front paws and their chins.

Beaver teeth, as mentioned, are fortified with iron rather than magnesium. They are harder at the front than inside, which means the backs of the teeth wear down faster to create a sharp edge. The teeth continue to grow four feet per year to counteract the wearing down from gnawing on trees.

Dams and lodges

Beavers live in lodges but sometimes they build dams to create deeper ponds. They need a pond that is deep enough to stay unfrozen at the bottom through the winter.

They keep a cache of branches underwater, outside the lodge, to sustain them through the winter because they don’t hibernate. During the summer they eat a lot of fresh leaves and plants; in the winter, they eat the branches they’ve stored. Sometimes they’ll eat the roots of underwater plants. They are strictly vegetarian; they don’t eat fish.

The lodges they build are structurally made of tree trunks and branches and stones. They are filled in with bits of plants and mud. The mud is very important because it dries above the water, making the lodge very sturdy. This protects the beavers from predators. Even bears can’t smash through the lodge. h Scan me

How beavers build dams.

https://www.youtube.com/ watch?v=yJjaQExOPPY

Castoreum

Two sacs in a beaver’s pelvis contain castoreum, an oily liquid. The beaver uses it to mark its territory. People use it for medicine, perfume and to flavour foods.

Ancient Romans used to burn the oil in lamps and Roman women believed inhaling the fumes could induce an abortion. Medieval beekeepers used it to increase honey production, though not sure how.

These would be for the Eurasian beaver; Europeans didn’t know how much castoreum there was to be had in the world until they got to North America and found up to 90 million of the Canadian creatures, which they hunted nearly to extinction over 400 years. The trade in Canadian beavers goes a long way to explain European settlement of this cold land, largely for beaver pelts. The castoreum was a nice by-product.

Castoreum has an analgesic effect owing to the salicylic acid beavers ingest in the form of willows. It was used to lower fevers, reduce pain and to treat hysteria. Flavour-wise, it has at some point been added to foods to enhance the flavours of vanilla and strawberry. It is too expensive, though, to be used in widespread production. In the perfume industry, it is used today in some high-end perfumes for the scent of leather or tobacco; only 300 pounds per year of castoreum are used in the commercial market.