Missouri Master Naturalists- Springfield Plateau Chapter

Saturday, January 5, 2013

Beaver Battle


Beaver willow harvest
It has been a good beaver year on Bull Creek... or a bad one depending on whether you are a beaver or the land owner.  Every year at this time the beaver dams appear and the willows along the downstream banks start to disappear, only to reappear as pealed sticks in the creek.  It is always a treat to check out as we cruise the creek. 

Beaver love the willows whose bark is a primary food source. They can mow the gravel bar nearly clean and yet the next year it will be a dense thicket with thicker trunks.  With a renewable resource like this, we should be theoretically able to enjoy beaver entertainment forever.

Threatened riparian bank
We have never gone a year without beaver living along our banks.  Unfortunately, every few years the parents will make their way upstream and then the problems begin.  Suddenly there are new mature bankside trees girdled daily.  With time, some are felled while the rest are sentenced to death by lack of circulation.  Trapping a few will give the problem areas some time to regenerate but a few years later the numbers increase and the tree slaughter begins again.

This year the damage was particularly dramatic, killing over 50% of the trees along the oxbow pond.  Pencil point stumps both fresh and old dot the area, a few surrounded with a dozen suckers sprouting into a replacement. While we are invested in expanding the riparian plantings, they follow their dietary urges, decimating the existing mature corridor.  Man is now their only significant predator.
"In some situations, these animals can enhance the value of wetlands for other wildlife. Yet, populations of beavers must be closely monitored and occasionally controlled to avoid problems associated with their over-abundance." MDC

Trapping is now a part of the balance of nature in Missouri and it is now trapping season* through March 31.  I quit trapping some years ago.  Wading in waist deep water, and reaching down into the freezing water to set the traps is a younger man's sport.  Traps must be checked every 48 hours.  Cleaning and stretching the pelt on a willow frame took hours and ended any "mountain man" fantasies quickly. 

50# plus beaver
We had friends come in to trap again this year.  They caught two big fat beavers on this stretch of creek, each weighing 50 pounds or more.  We assume that these are the parents of the offspring living downstream.  One way to know that the beaver are all gone from the area is to break a hole in their dam.  They will generally repair a hole overnight.  The dam is now remaining open and hopefully the remaining trees are safe for now.

Disrupted beaver dam
Some years ago when I was trapping beaver, I worked over an hour to create a hole in a two foot high dam across a wide stretch of Bull Creek.  I set a trap six feet up stream above the hole, anchored with large cedar poles creating a channel they would have to enter to do their repair work.  The next morning I found the dam repaired with my trap and the poles deeply imbedded in its structure.

It should be several years before the beaver population reaches a level where they are destroying the large trees.  As long as they are feasting on our tasty willows, we will remain good neighbors.

* Off-season trapping is only done by the Missouri Department of Conservation when beavers are causing significant financial damage.  This includes destroying urban plantings and obstruction of waterways of importance.