Image credit Alexander V. Badyaev in National Wildlife
The North American beaver (Castor canadensis) was the topic of an article entitled Masters of Downfall that I just read in the Aug/Sep 2015 issue of National Wildlife, the magazine of the National Wildlife Federation.
Specifically, the article focused on how beavers fell trees, which as it turns out, is NOT random at all. In fact, they are quite skilled at making trees fall where the beavers want them to.
The author is scoping out beaver activity in Montana, where he tells us:
Two groups of beavers seem to be working in shifts, circling two giant Douglas firs that already have deep cuts. I'm entirely within the range of these 150-foot trees, and as I fire my remote camera to photograph the beavers' activity, a realization sets in: "I have completely entrusted my life to the mind and engineering skills of a rodent."
Again, here is the link to the NWF article, which you really must go read. You'll be glad you did.
Oh, and the link to Ultrarunning? Several years ago I was on a business trip to Washington, DC, and after work drove out to the Great Falls (MD) area to take a long run along the C+O Canal. As dusk began to gather, I saw a large black shape on the trail in front of me silently and easily slip into the water. When I say "large," I mean German Shepherd size, minus the legs.
I suddenly realized it was a beaver--a very large one--and that I was so fortunate to have seen it. It must have reached the area via the wild Potomac River corridor...yet it was a scant 10 miles from the White House.