Thursday, June 13, 2013

Beaver Ingenuity

On my neighbor’s property about half of a mile from my home there is a small stream which drains the surrounding land.  Some of this land is very good crop acreage, while some of it is more swampy, and of little farm use.  My neighbor, needing access to his crops on both sides of the stream built a farm road across it.  He hauled in sandy soil building the road up to about 4’ higher than the stream bed to make it high and dry.  In the process he installed two sluice pies at the original stream bed level.  One of these is about 30” in diameter, while the other is near 16” across.  They are located approximately 20’ from each other.
Shortly thereafter a pair of beaver moved into the area upstream from the road that my neighbor had built.  Whether by instinct, or constructive thought, the enterprising beaver found this to be a relatively easy place to form a pond.  All they had to do was stop the water from flowing through the two pipes, and magically over a short period of time a pond would materialize in which they could live relatively safe from most predators.
Bucky and Eagar Beaver, as I named them, set to work as busy beavers will do, and before long had completely blocked the end of the large pipe with sticks and mud dug from the bottom of the steam bed thus deepening the water at the same time.  They continued adding material until they had their plug several inches higher than the top of the pipe, and extended well beyond the extremities of the pipe itself.  This would seem to be rather an instinctive bit of engineering as building ponds by blocking water flow is what beaver have been doing for centuries.
However, when it came to the smaller pipe the workaholic animals used a completely different tactic.  Instead of plugging the end of the pipe as they had done with the large one, they instead built a dam some two feet back from the end of that pipe completely surrounding the inlet end of the pipe, but leaving the end of the pipe open.
Due to abnormally heavy rainfall recently the pond has been growing deeper, and at the same time larger.  Yesterday the water began to overflow the dam at the end of the smaller pipe effectively maintaining the water level at the dam height.  This ensures the water level in their den built some 100’ back from the dam will not rise to a height threatening their living quarters with flooding.  As of this time they have made no attempt to slow, or stop, the flow of water over the dam.  Thus it would seem this is a well-thought-out water level control system.  Is this yet instinctive, or can it be real thought?