Beaver

Let’s take a look at the most celebrated of the animals which share their lake with us - the beaver. A possible reaction to this choice of topic is, “I know about beavers already - I’m Canadian”. However, we hope to condense the daunting volume of information about Castor canadensis and offer text, videos and diagrams that will interest and entertain you, as well as adding to your knowledge.

To begin, let’s view a 5 minute video that may well - in the words of the hyper-enthusiastic host - change the way you look at the beaver. Press Play and enjoy “Smartest Thing in Fur Pants”

Beaver History

Several million years ago the Eurasian Beaver migrated to North America and evolution resulted in our Castor canadensis, the ‘modern’ beaver.

In the Pleistocene Ice Age—the era of the mastodons and the mammoths— and until 10,000 years ago, there was a ‘giant’ beaver variant which likely weighed as much as a modern black bear.

In the 15th Century there were approximately 60 million beaver in North America, and the animal served as a prime food and clothing source for the indigenous peoples. The arrival of European colonists was closely followed by the fashion rage in Europe of fur hats (more correctly ‘felt hats’). European beaver were wiped out - and beaver trapping in North America commenced.

"Canada was built on dead beavers" Margaret Atwood

By the end of the 1800’s the beaver population of North America was almost completely eradicated. Not until the mid-1900’s was there a resurgence in the population, which now numbers approximately 10% to 20% of the pre-colonization levels.

The reintroduction of beavers is continuing in Europe and North America. It is gratifying to see the results of a lot of hard work, including the ‘attitude adjusting’ of people who have indeed been inconvenienced to some degree by the beavers’ engineering work.

The beaver have not returned to all parts of their former range. Some grassland areas are still suffering from the lack of the beavers‘ ecological maintenance’, but elsewhere there is an overabundance of beavers, to the point that there have been some instances where the beaver have been considered a nuisance.

Keystone Species

A keystone locks all the other stones in place making the structure stable and strong. In recent years biologists have started to recognize certain animals as “keystone” species; a species that creates or maintains the habitat for many other plants and animals. Beavers are considered a keystone species in North America for the way they shape their ecosystems by building dams that create a wetland habitat in which many other species thrive.

This is another way of saying that beavers play a crucial role in biodiversity. Innumerable species rely either partly or entirely on beaver-created habitat, and many of these species are either threatened or endangered. Therefore, whenever we can coexist with beavers, we are providing the habitat necessary for supporting many other species, and protecting the web of life upon which we all depend.

In addition to the very important biodiversity issue, many people are not aware that there are many other benefits to beaver ponds, as outlined below.

Direct Benefits to Humans

Decrease damaging floods
Recharge drinking water aquifers
Remove pollutants from surface and ground water
Drought protection
Decreased erosion

Other Benefits

Produce food for fish and other animals
Support biodiversity, including 43% of our endangered species
Increase salmon populations
Create various vital habitats
Repair incised and damaged stream channels and watersheds
Preserve open space
Maintain stream and river flow
Greater opportunities for; Wildlife observation, Hunting and trapping, Canoeing / kayaking, Fishing, Photography, Bird watching and Quiet relaxation in nature

Amazing Adaptations

The beaver’s most notable feature is its large flat tail. This leathery tail (which can be 15 inches long and 6 inches wide) has many functions and when combined with the large webbed hind feet allow the beaver to swim at 6 miles an hour.

When a beaver strikes its tail on the surface of the water it is using its tail as a communication tool to warn other animals of predators.
Its tail serves as a rudder when swimming and helps to maintain course when ferrying trees and branches.
The tail also assists as a brace or a stool when sitting or standing upright or when gnawing down trees.
Beavers put on body fat in the fall to provide insulation as well as store energy. A beaver's tail is designed to store fat and it shrinks in size over the winter as the fat is used up.

Other adaptations to an amphibious lifestyle include eyes, ears and nostrils which are situated high on the head so they can maintain vigilance when swimming.

The nostrils have special muscles that close the nose tightly when diving.
The ears too have special muscles that allow the ears to fold flat, thereby preventing water from entering. The ears are also densely furred inside; this fur traps air and stops any water seeping in.
The eyes have a third, clear eyelid called a nictitating membrane that does the work of goggles and allows them to see underwater.
In contrast to humans, beavers have an epiglottis at the back of the nostrils rather than in the throat; this flap of elastic cartilage prevents water from entering the windpipe when diving and swimming. Also, the back of the tongue can rise and create a waterproof seal.
In addition, behind their incisors they have inner lips that allow them to carry sticks in their mouth while swimming without getting a mouthful of water.

The beaver has many adaptations that conserve oxygen.

This includes large lungs, a big liver that stores oxidized blood and slow circulation to its extremities, allowing the animal to stay submerged for up to 15 minutes.

Rodents have very different teeth from most mammals.

Rodents’ teeth keep growing all their lives. Rodents have to constantly gnaw hard substances to keep their teeth from getting too big for their mouths. Beaver teeth have an extreme growth rate, up to 4 feet a year! That’s longer than the entire body length of an adult beaver. Because they’re not worried about wearing their teeth down, beavers are free to chew on as many hard objects as they can get their incisors on.
Their teeth usually look orange or brown - this coloration isn’t caused by staining from their environment, but rather from iron in their tooth enamel. Beavers only have enamel on the front of their teeth. The dentin at the back of their teeth wears away faster thereby creating a sloping angle on the teeth, a perpetual chisel edge.
Beavers are herbivores and like to eat the bark and the soft cambium layer beneath the bark (not the hardwood) as well as the twigs of poplar, aspen, birch, willow and maple trees. They have unique micro-organisms in their guts that help them digest as much as 30 percent of the cellulose they eat from plants.
Beaver teeth are so good at cutting wood that they were used as tools by early humans. The oldest known wooden statue is believed to have been carved in part with tools made from beavers’ jaws!

The following video is an amazing look at how effectively the beaver is able to cut through wood.

Beaver’s Fur

A beaver’s fur coat consists of two distinct layers: an outer layer of long straight “guard” hairs and a softer, densely interwoven inner layer. This inner layer was the natural felt used to make the top hats responsible for the demise of so many beavers from the late 16th century to the mid 19th century.

The beaver waterproofs both layers of fur with oil produced by its castor glands near the base of its tail, applying the oil regularly by using the split grooming nails on its front feet. This waterproofing is so effective that very little water actually contacts the beaver’s skin.

The Lodge

Beavers build and maintain houses called lodges. There are two main types, the conical lodge and the bank lodge. The most recognized type is the conical shaped dwelling surrounded by water. It is made from sticks, mud and rocks. One of the primary reasons beavers build dams is to surround their lodge with water for protection from predators.

The second type of lodge is the bank lodge. It is typically excavated into the bank of a large stream, river, or lake where the water is too deep or fast moving to build the classic conical lodge. Within each lodge beavers will hollow out a chamber where they sleep, eat, groom each other, and the baby kits are born and nursed each spring. Bedding of grasses, reeds and wood chips are changed regularly. In order to breathe fresh air beavers do not apply mud to the peak of the lodge, creating a ventilation shaft. Note: If you have an opportunity to visit a beaver lodge on a very cold winter day, look very closely and you may see the beaver’s breath escaping from this chimney-like peak, or even hear the murmurs of the beaver family inside.

Each lodge contains at least two water-filled tunnels leading from the chamber to the pond so the beavers can enter and exit the lodge underwater without being spotted by predators. The walls of the conical lodge are very strong due to layers of mud and sticks, and are well insulated. Even with subzero outside temperatures it will not drop below freezing inside the lodge due to retained body heat from the family of beavers.

Let's take an inside Look at a Beaver Lodge! filmed by Jeff Hogan

In the Hotel lake Area

You may be familiar with the bank lodge on Hotel Lake and see it on canoe trips or pass it on daily walks along Hotel Lake Road. In our area a second less well known beaver lodge lies in the wetlands north of the lake; there may be others.

But the writers of this article must admit to limited sightings and then only of a single beaver. Beavers are described as mainly nocturnal and crepuscular (active at twilight). This characteristic is confirmed by the fact that we regularly see a single beaver doing a “patrol” of the lake in the early evening and at some point in his travels visiting our little bay off Acadian Road to nibble on the water lilies.

You might remember in the opening video, the presenter mentions how beavers are drawn to the sound of running water and how energetic their behaviour is in plugging any “leaks”. From October to April, water from Hotel Lake leaves the lake via Hotel Lake Creek “running” across the driveway close to Lot 8. It is during these times that we are most aware of our beavers. The beaver(s) brings sticks and branches to stop the water from leaving the lake. They have also been known to go further onto this property, following Hotel Lake Creek into “Chubb Pond” to impede the water from leaving the area via the culvert under Beaumont Road.

2022, Words from neighbour, Jim Little

"We often watch the beavers at nightfall on our dock. At times we have seen two adults and at least two kits swimming past our dock and chattering back and forth. One evening in June the two adults were hovering off shore, appearing to want to come on to the beach. We decided to leave them in peace. The next morning I found a few small trees had been cut down near the shore by the beavers. A couple of large branches remained on the beach. On previous occasions we had removed such branches, but this time on a hunch we left them there. The next morning the branches were gone! All that remained were the drag marks on the beach."Jim Little

It also seems reasonable to surmise that the sticks and branches that plug up the culvert on Irvine’s Landing Road might also be the work of beavers. These actions by beavers residing on the north side of Beaumont Road would be an attempt to keep water from leaving their wetland area.

Beavers are monogamous and mate for life. They are described as having one litter a year, usually in May or June, of 1 to 6 kits. The colony in any one lodge typically consists of the adult pair and the kits from the previous 2 litters. The parents and young beavers from the earlier litter look after the youngest kits. They carry them away from danger, clasped to their chests with their front paws. Beavers cuddle their kits and call gently to them. 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.

Our knowledge of the size and activity of our local colony is limited. Have you seen evidence of our beaver family and the behaviours mentioned above? We would invite you to respond with your sightings, photos, interactions and knowledge of the beaver(s) in our area. A future newsletter could have an addendum with our shared information.

March 2022: The photos below are on the island on the north west side of the lake. On some evenings this past summer we would see three beavers on the small floating dock off our main dock.

In Praise of the Beaver

North American First Nations revere the beaver. They recognize that the landscapes beavers create are helping to purify water and regulate its flow. They notice that beavers are highly social creatures who go to great lengths to care for their offspring. For these reasons, Native Americans called them the ‘little people.’

The beaver is also seen as a symbol representing wisdom because he uses his natural gift wisely for his survival. The beaver alters his environment in an environmentally friendly and sustainable way for the benefit of his family. Beavers are considered a family oriented species that are peaceful, persistent and hard-working.

For these qualities and for the place beavers hold in the history of our country, the beaver was proposed in Parliament as an emblem of Canada. The beaver was made an official national symbol on March 24, 1975 by a private member's bill introduced in the House of Commons by Sean O'Sullivan and seconded by Joe Clark.

Victoria based writer, Frances Backhouse is the author of two books on beavers:“Once They Were Hats” and “Beavers: Radical Rodents and Ecosystem Engineers”. Her words: “The Mighty Beaver, arguably North America’s most influential animal, apart from ourselves” nicely sum up our topic.

Since 1963, the Canadian Wildlife Federation and Environment Canada have been producing top-quality video spots supported by detailed fact sheets, lesson plans and calls to action, all in the name of understanding and protecting Canada's diverse wildlife. The evocative theme music, now ingrained as part of Canadiana for the young and old, persists in each new spot produced today--whether in its original, haunting form, or updated with a youthful beat for student-focused videos.