Beaver Population Density? Or populace DENSE about beavers?

   Posted by heidi08 On June - 12 - 2013

Toward an understanding of beaver management as human and beaver densities increase

Human–Wildlife Interactions 7(1):114–131, Spring 2013. Siemer, Jonker, Becker & Organ

Attitudes toward beavers were more likely to be negative among people who had experienced problems with beaver, and intensity of negative attitudes increased as the severity of problem experiences increased (Siemer et al. 2004a, Jonker et al. 2006). Norms about lethal management also were closely correlated with problem experience. Acceptance of lethal management tended to be higher among people who had personally experienced problems with beaver (Siemer et al. 2004a, Jonker et al. 2009). When presented with a range of interaction scenarios, people who had experienced beaver damage were more likely to accept lethal management actions in any scenario where beavers had a negative impact on people.

So people who are inconvenienced by beavers, (or worried they’ll be inconvenienced by beavers) are more comfortable with killing them than folks who’ve just seen them on the TV? And this gets published as research? I am reminded of Horatio saying sarcastically to Hamlet,

“There needs no ghost, my lord, come from the grave to tell us this!”

This study revisits the Massachusetts beaver issue and the least-liked voter decision apparently in the history of the world. A 1996 referendum that indicated folks wanted it to be harder to kill beavers cruelly. This is vociferously blamed for ruining every sense of balance the state had previously developed. Even beaver defenders thought the the referendum had ‘tricked’ the voters (although how straight forward are most ballot issues, I ask you?) Once it was passed, alarming reports filled the air like spring pollen. Authorities said the population subsequently exploded because even though you could still use lethal techniques and even though you could use the old methods as long as one of 9 tiny conditions were met, it still took five minutes more time to kill them than it used to and that created anarchy. (Folks in the bay state are very busy and obviously no one has 5 more minutes to spare killing beavers.)

Hence the article, which is based on public attitudes towards beavers and a questionnairre that got mailed to folks who complained about beavers (and for appearances sake, some folks who didn’t) in 2002. Surprisingly, the folks who DIDN”T COMPLAIN didn’t return the survey as much as the people who were mad. (Gosh!) And the two groups said admittedly different things in general, but the researchers knew just how to handle this conundrum to get the results they wanted.

We detected some differences in each state when nonrespondents were compared to respondents (for a detailed description of respondent-nonrespondent comparisons, see Jonker 2003 and Siemer et al. 2004a). Although we found differences between respondents and nonrespondents, we decided not to adjust the data to account for potential nonresponse bias.

Because really, who would you want to do that? It doesn’t matter and it further doesn’t matter that the data for this study is 11 years old. This study is very important. They obviously only questioned residents who were smarter than the average bear. They were PSYCHIC! How do I know they were psychic? Read for yourself.

Sixty-one percent of respondents in the High beaver density group perceived a statewide increase in beaver damage over the previous 5 years. Only 24% of respondents in the Low beaver density group perceived that beaver damage had increased.

Remember, this was 2002. A scant 6 years after the voters passed the referendum to outlaw trapping, which the politicians took another few months to craft into law. Which means it wouldn’t have affected the 96 season. The state only has 2754 square miles of water, so there were a limited number of beavers to start with. Even if there were 1000 yearlings poised to disperse that first year, research tells us they mostly couldn’t breed until their third year or 1999. Now we’ve seen first hand that the first time a beaver has kits the numbers are low. So 500 kits born that year and 1ooo born the following year. Meanwhile a steady stream of yearlings is marching on with similar successes. Lets assume, of course, that these kits weren’t killed some other way or exposed to round worm parasite and die like nearly half of ours did. Let’s assume that the conditions in Massachusetts are so pristine and predator-free that the population gets as big as it can possibly be in those 5 years and increases by 500%.

I suppose 5000 new kits could be impactful. but remember none of these off spring will be ready to disperse until the year 2002 when this study was done, so its hard to imagine folks were feeling the burden of the booming population when these  questionnaires were being filled out. Just to be clear, that means folks who wrote that the population was EXPLODING were actually writing that they were IMAGINING it would explode in the future and blaming their beaver problems on the new laws without actually understanding what was happening.

Heidi, you’re so picky. What about the part of the survey where they talk about flow devices and how attitudes change with successful installation? Don’t be silly. They didn’t mention flow devices at all. That’s right, in this entire discussion about WAC (Wildlife Acceptance Capacity) they did not mention the one factor that might  conceivably affect this attitude. Because the researchers obviously knew that beavers were ‘icky’,  and grant money was freely awarded to folks who said so. The good news for the authors is that as the population climbs more and more folks will get annoyed and become more willing to kill them.

Well, that’s something to look forward to.

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