A unit of Lasting Forests
Sustained forests; sustained profits
evolving since March 30, 1999

of an Alternative Wildlife Resource Management

Trapping Beavers: The Myth of Decision-Support Systems

A forester and laborer drove down a dusty road in late summer. Rounding a sharp corner, they were faced with leaves and brush in the road. "Tree down across the road!" was the observation that almost anyone could make. No decision needed there!

"I wonder how that happened." They both got out of the truck and followed the tree trunk to the base. Any TV-watcher over the age of 4 could tell it had been gnawed through by a beaver.

"I didn't think we had beavers around here."(Presence 1)

"What is their local range? (Local range 2)

"Are we on the edge of their range and are they expanding? I heard that they had been very widespread but that they disappeared with settlement.(National range 3) (Continental and world range 4)(Brief history 5)

"Do you have a saw in the truck?"

"No. It is always a problem deciding what to bring on these trips. I could fill up the truck and still wish for one more thing. (Daily service equipment 6) I do have an axe. "

"Thank goodness! Hey! It's a double-bitted one. Why did you bring that kind and not the single bit? "(Equipment type 7)

"More versatile, I guess, but I grabbed it from next to the door when I left. What safety issues do we have here? " (Safety instruction and training time allocations 8)

"None, just stand back! I'm wearing my steel-toed boots." (Requirement to wear safety clothing in the field Vs efficiencies and comfort 9)

"What kind of tree is that?" (Species identification 10)

"Does it always grow where it is damp?"(Silvics for 50 species of trees in a region 11)

"Why do you think the beaver felled it into the road?" (Details of beaver life history and dam building 12)

"It didn't have the road in mind, I assure you. It was cutting wood for the dam and using it to plug the culvert crossing the road down there."

"That's a small culvert."(Proper culvert size within a watershed 13)

"How are we going to stop the beaver from cutting more trees?" (Should we try to stop it 14) (If yes, how 15) (If no, consequences 16)

"We can walk away and assume it is only cutting a few trees and that they are not very valuable and who ever finds the next tree will also have an axe or a saw. To walk is a big decision. "

"The beaver are more valuable that one or 2 of these kind and quality of trees." (Local stumpage estimates 17)(Local fur prices 18) (Local attitude toward wildlife not present but potentially recovering 19)

"We ought to try to get help from a trapper." (List of trappers 20)(Trappers with live traps available 21)

"I wonder what kind of bait they use." (Trapping techniques 22)

"None. But I worry about growing sentiment against trapping." (Probability of local offense 23) (In-house policy on trapping as a serious profit-loss reduction operation 24)

"Where would the trapper take the beaver if they caught one?" (Current range and "non-range" or places where losses would be tolerated 25)

"Maybe we could make some money by encouraging beavers and managing them for fur, meat, photography, educational tours, and castor....and start worrying about diseases they harbor and then contaminate stream waters."(Total net financial benefit potentials 26)(Disease public health risk analyses 27)

"What's castor?"(Commercial uses of animal organs 28)

"The glands at the hind legs. The oil is used as a perfume fixative"(Commercial potential and development 29)

"There's a lot of talk recently about exporting products. Maybe there is a potential for exporting glands from a well-regulated beaver population managed for fur and other products." (Commercial development and business plan 30)

"Could we export castor?" (CITES (endangered species, etc.) laws and export and customs laws, regulations, and tariffs 31)

"Let's not discuss exports before we chop through this tree. How many cuts can we get by with and still roll the logs?"(Local tree weights and efficiency 32)

"I've seen pictures of elaborate structures that prevent beavers from plugging culverts and thus protect roads from flooding or washout." (History of such efforts and best current practice 33)

"What if we do clear the tree and trap the beavers. Won't they return? I hear that they migrate upstream. I hear that young are driven out of their homes by their parents." (Restoration ecology 34)

"Correct. We'll continue to fight them from here on."

"Is this a new and perpetual cost of forestry?" (Forest health, invasive species, etc. 35)(Forest economics models 36)

"Only on some areas. Maybe pest work can become like forest fire accounting." (Forest tax law 37)

"The boss might make more money from his farm and these 2 forest tracts with the beaver losses than he would if he spent a lot of time and money on trapping and beaver removals." (Total net return calculations 38)

"It will take a computer to figure that out. What about these beavers? If we trap them and release then somewhere else, will they return? "(Homing behavior 39)

"Maybe we could just trap and remove the females."(Beaver external sex characteristics 40)

"We do not even know how many there are here at the culvert or in the watershed."(Population estimation techniques 41)

"Maybe we have no worries. This could be like a random event. We can watch and see what happens next. Maybe predators will wipe them out."(Predator-prey population relations 42)(Loss of former large predators such as lion, bobcat,wolf 43)

"They cannot cut but so many trees. Maybe 'Nature knows best'"

"Trees cut are not the issue. Trees that die after an area is flooded is the problem. They work up the banks around their water bodies but the acreages flooded are some of the best tree-growing sites. One family of beaver can kill superior trees over many acres."(Silvics and flooding and riparian area ecology 44)

"Beavers slow the water, it warms, and good trout water can be reduced in quality...but small-mouth bass go crazy in such waters."(Trout fishery management 45)(Trout and Bass tradeoffs 46)

"I'd say let the trappers have at them.... But maybe there are many trappers and allocating beavers among them can be a problem. In Canada there are allocations of trapping areas made by the government. Would that be necessary?"(Area allocation 47)

After much chopping and log rolling they sat eating their lunch. (Policy:always bring lunch 48)a man appears walking down the road. "What are you doing with my logs?"he said.

The "warm" conversation that followed included property lines, old owners, questionable corners, who owned the water rights,and whether the logs were on the right-of-way and whose property they really were.

Brought from the truck, the recent GIS map was studied by the three men. (GIS ownership and watershed boundary and stream channel 49)

They finally departed, the old guy continuing to walk down the road.

"Should we have given him a lift?"(Local etiquette 50)

"Do we have get these lines re-surveyed to be sure about whose log that really was?"(Survey or re-survey contract 51) Who will we contact? Who did the boundary (Contract history 52)and when is it scheduled to be re-painted? (Boundary marking scheduling 53)(Contract work or employees 54)Are these 'our' beavers and will we be sued by that guy if our beaver's water floods some of his trees?

"Keep chopping; I don't know! Back to the beavers. If we have 3 kinds of traps, 2 kinds of poisons,2 systems of trapping, and a treat-not treat decision, then we have at minimum 24 different options from which we must select. If we do about 7 separate things in various sequences, then the permutations of those 7 things is 5040 options. Picking the very best option from among them is tough. It is very easy to be good but not correct. The land, in my opinion, has been destroyed by the relentless practice of well-meaning but poor decision making. Hundreds of C- and D-grade decisions, all following after each other, produces a failing system."

"If we knew who should be deciding...from the boss in the big house, to me standing here chopping, or that old guy down the road... then the question remains."(The properly designated decision maker 55)

"What's that?"

"How would you know what is a good decision? (The objective function, what to maximize, stabilize, or minimize...the desired net expression 56). Then if we knew, we would have to face: How can we get it all together?"(The integrative model for satisfaction 57)

In wildland management, there are decisions that range from whether to go to work on a day because of stomach cramps to whether a decision made during such a day may threatened the existence of a form or life or close a mill for an entire region forever. There are at least 57 such decisions related to the simple local issue of beaver trapping. Over and over techniques for making decisions have been developed but use has been poor or fragmented. Agencies have created tools and the agency has disappeared before the tool was marketed and benefits gotten from the investment. There have been failures. There have been simplistic systems and excessive systems. There have been educational systems that have failed in application. Field systems have failed to be very educational. Many systems have been designed for the wrong decision maker. Many have had unclear objectives and everyone knows what that can yield.

New technology now makes some decision techniques available in the field. Deciding on the decisions to be addressed is important. The funds available, the ideas, the agency, the people who decide what is important all influence the decision. Techniques for solving hundreds of trivial decisions can be created. Years can be spent in inventing the single decision method for "the big decision" (which may never be made in the winds of globalization.) Some difficult decisions must be made about how to improve decision making. We need the results of an excellent system to create a system.

Maybe we need well-educated people in decision positions undergoing continual education. With encouragement and protection, a backup team for information and review, and clear applications of feedback, things could get better, fast.

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This Web site is maintained by R. H. Giles, Jr.
Last revision May 3, 2000.