Picture Source Nationalgeographic
Wondering why that title? The Native Americans believed that the Beaver was the “sacred center” of the land because it creates rich habitats for other mammals, fish, turtles, frogs, birds and ducks. Beavers prefer to dam streams in shallow valleys & much of the flooded area becomes wetlands; and wetlands are cradles of life with biodiversity that can rival tropical rain forests. Almost half of endangered and threatened species in North America rely upon wetlands for survival.
Beavers reliably and economically maintain wetlands that can sponge up floodwaters (the several dams built by each colony also slows the flow of floodwaters), prevent erosion, raise the water table and act as the “earth’s kidneys” to purify water. The latter occurs because several feet of silt collect upstream of older beaver dams, and toxics, such as pesticides, are broken down in the wetlands that beavers create. Thus, water downstream of dams is cleaner and requires less treatment.
This week let us get to know the Beaver better…
- Beavers are around 2-3.5feet long with a paddle like tail measuring between 7.5” to 12”.
- Adult beavers weigh 40 to 60lbs (27kgs)
- Beavers mate for life and give birth to 1-4 kits in spring. Both parents help in rearing the kit.
- Beavers are semi-aquatic mammals which spend their life in and near shallow water bodies.
- Beavers are well insulated by a pelage that consists of long over-fur (guard hairs) and dense under-fur. Their fine coats are waterproof naturally and made them a primary target of fur trappers when fur trade was rampant.
- There are only 2 species of Beavers; they inhabit North America(Castor candensis), (Castor fiber) Europe and Western Asia.
- Beavers are active throughout the year through winter.
- One Beaver can chop down 200 trees a year!
- Beavers are amongst the largest rodents in the world and are herbivores which feed on Leaves, Barks, Twigs, Roots and Aquatic Plants.
- They are a Keystone Species. (A keystone species is a species that has a disproportionate effect on its environment relative to its biomass. Such species affect many other organisms in an ecosystem and help to determine the types and numbers of various other species in a community. Source wikipedia ) Meaning removing them from the environment will impact the whole ecosystem around them.
- Beavers are busy all the time re-engineering the habitat around them. They prefer banks of rivers or ponds which are shallow with slow flow or none at all.
- They build dams to transform less suitable habitats to their liking.
- Beaver homes are called “Lodges” and are built of branches and mud. They are located strategically in the middle of the pond or water body with an accessible under water entrance.
- The lodges are built to house colonies (more than one family peacefully co-existing).
- Beavers build dams to create deep, still pools of water to protect against predators, and to float food and building materials.
- They walk on land with an ungainly swaddle, but are graceful in water. Beaver’s hind legs are webbed and help them swim. The paddle shaped tail is used as rudders for steering.
- They can swim up to speeds of 5 miles an hour!
- A beaver can transport his own weight in material, and will drag the logs along mudslides and float them through canals to get them in place.
- After being hunted extensively for a couple of centuried the beaver is making a strong comeback in much of Canada.
- Beavers are second only to humans in their ability to manipulate and change their environment.
In April of 2008 an Ottawa scientist Jean Thie discovered what he believes is the largest Beaver dam ever while scouring for signs of climate change via satellite imagery. The 850 meter or 2790 feet long dam is located just south of Lac Clair in the Wood Buffalo national Park, Alberta, Canada. It is twice the size of what was the world’s largest, the Hoover dam in the U.S. which spans 1,244 feet! Jean Thie also saw two smaller dams being built on either side of the big dam, he believes in time these will be a single structure spanning almost a kilometer!
Details about a beaver Dam :
A common myth is that beavers use their tail to carry and pack mud for dam building, in reality beavers carry mud by holding it against their chest. Spillways and passageways are built into the dam to allow excess water to drain off without damaging it. Dams are generally built wider at the base, and the top is usually tilted upstream to resist the force of the current. Trees approaching the diameter of 3 ft. (.9 m) may be used, but the average size used to construct a dam is 4 to 12 in. (10 to 30 cm). The length will depend upon the diameter of the tree and the size of the beaver. There are recorded cases of beavers felling logs of as much as 150 ft. (45 m) tall and 5 ft. (115 cm) in diameter. Logs of this size are not intended to be used as structural members, but rather the bark is used for food, and sometimes to get at upper branches.
Probably it is all this that makes them interesting to us.. they are after all nature’s engineers!