Sunday, August 15, 2010

The Rodent King

Strictly speaking, rodent is a neutral term for any member of the order Rodentia. Let's not kid ourselves though, there is a distinct negative connotation. Rodents may simply be mammals whose teeth grow for life but the term brings to mind rats, mice and other vermin. Historically rodents are unpopular for two reasons, peskiness and pestilence.

Until recently I thought of rats as the big rodents and mice as the small ones. Wrong. Apparently beavers are the King of Rodents. At least they’re the largest rodent in North America,weighing between thirty and sixty pounds. Personally I don’t think size is everything but who am I to argue with the author of North American Mammals?

As with all kings, the beaver has its detractors, naysayers on the sidelines who criticize or even plot against them. I’m not talking about the squirrels here, I’m talking people.

Fittingly the charges leveled against the beaver, king of rodents, are the same as those leveled at his smaller cousins:

1. Pesky Pests

According to some, beavers rain down environmental degradation on innocent forests continent wide. Beavers create ponds and canals to get to the best trees. Understandably landowners may be dismayed, not thankful that their property is flooded just so beavers can float about in relative safety while snacking on alder, willow and poplar bark. Moose though appreciate beaver bogs, as aquatic plants are their diet of choice. I myself have fallen into an inconvenient beaver bog. They are wet. But it's part of the natural balance, isn’t it? It’s a return to how things were before beavers were hunted to near extinction, right?

Maybe their numbers are getting out of hand, but I haven’t read that anywhere. Actually I’ve read that beavers are an important part of a wolf’s diet. Beavers also fall prey to coyotes, bobcats, lynx, bears, mink, wolverines, river otter and people. It’s no wonder they like to stay in the water.

2. Pestilent Pests

Hiking behind some loud guys complaining vehemently about beavers, I overheard, “They cause giardia. They shit in the water. That’s why they call it Beaver Fever.”

Beavers do defecate in water, they also eat their feces in winter, but beavers aren’t the only ones spreading giardia. Cows, sheep, deer, cats, dogs and children readily transmit giardia too. Sure kids are supposed to wash their hands, cows and sheep are supposed to be fenced far from streams, but really people get lax about these things.

Deer and beavers on the other hand, roam free of rules and regulations. There isn’t much you can do about it, outside hunting season, so beware. Treat your water. These nasty little flagellated protozoan parasites called giardia can live in water for months, even if it looks clean.

[To learn more about beavers I consulted several books, all of which sang only the praises of beavers (they are clever, industrious and they have the most beautiful luxurious fur). Most helpful were Tracking & The Art of Seeing 2nd Edition by Paul Rezendes, who talks about wolves eating beavers on page 87. And North American Mammals by Roger A. Caras, Galahad Books NY 1967. The beautiful giardia photo above I gakked from the blog Worms and Germs.The other photo I took myself this summer at Fitzgerald Lake not far from my home in Florence Mass.]


  1. The first time I ever thought of beavers being pests is when I was walking on the far side of Paradise Pond at Smith College a few years ago. The beavers had chewed away at some fairly large trees, and it seemed they went from one to the other, doing damage, much like the picture you have above. As you know, some of those trees at Smith are pretty ancient. It was too bad seeing all those trees that had been damaged to the degree that they were not going to survive. Yet the beavers are as much a part of nature as the trees...

  2. You DO know about the 200 lb giant beavers that lived here during the Ice Age, right? check out the story behind Pocumtuck:

  3. Steve,
    That just may be the coolest Wikipedia page I've seen yet. Beavers with the teeth "the size of bananas" - wow. Thanks for the link!

  4. I am not sure if the Beaver is the true king of rodents. What about the R.O.U.S. that live in the Fireswamp?

  5. Mmm... Rodents of Unusual Size, eh? Well, if beavers are usual then R.O.U.S. would be bigger and I mean it. Anybody want a peanut? [If this makes no sense, you should watch The Princess Bride over and over and over again.

  6. I didn't know that beaver is the king of all rodents... We'll that is my lesson for today. Anyways, I've seen trees like that during hiking and I never thought that it is something to do with rodents.

  7. Rodents, rodents everywhere. I'm glad you got a nice lesson of the day. You dish out some pretty great lessons too. Hey, everybody, check out Dan's advice on preparing kids for the outdoors.