"DAM BUSTING"

Beaver (North American) - 5 Photos

Received my first lesson in dam building (or Dam Building 101) from a young beaver late one evening last week. Of course, it was a lesson completed vicariously. I did not physically participate. 

His/her mother had already done some of the heavy lifting but every beaver when they come of age, are obviously expected to participate in maintaining & helping to build structures such as dams & lodges.

The first dam repair appeared to be a minor one. There was a small gap which was allowing some water to escape. A person's first reaction would probably be to anchor some material such as large branches/tree trunks & stones to bridge the leak. 

There has now been research in laboratories to uncover why beaver dams are so resilient to flooding and can hold their integrity. The results have been that it is a combination of mud, grasses, stones & of course, tree material, basically brick & mortar that gives each dam its strength. 

What first came to my attention, though, was not what was placed on top of the gap but what work went on below the water surface. Before filling the gap with material, the young beaver dug deep down where the leak was occurring and excavated some of the mud. Then he/she proceeded to fill the hole with grasses, etc. to establish a foundation before finishing it off with branches and closing the gap.

Then it was a swim downstream to join Mum for some grooming (Photo #1 and another blog) before working together on a much larger dam that holds back pond water (Photo #2 through Photo #5). 

So my question, in my head, to the beaver was, "Where did you learn how to do that? Did you learn by watching or is it instinctive or a combination of both?"

PHOTO #1

PHOTO #2

PHOTO #3

PHOTO #4

PHOTO #5