Otters can swim faster than beavers; otters have flesh tearing teeth
and beavers are vegetarians;
and most of the books you pick up about the two animals announce that otters are predators of beavers. So it is obvious, when they are in the same pond, a beaver doesn't want to get in the way of an otter.
No one told the beavers all that.
In the middle of March, the ice on a large beaver pond had retreated from the beavers' dam and the lodge the beavers were using right next to the dam. I went out in the early afternoon of a day warm for the season, well above freezing, to see if I could see the beavers taking advantage of the thaw. Instead, I heard an otter snorting along the edge of the ice, and to my surprise, it didn't swim away. It got itself up on a shelf of ice and
kept snorting at me off and on, but also groomed itself!
Then some beavers came out of the lodge and swam off
to find sticks to nibble.
The beavers didn't look at the otter, and the otter didn't seem to look at the beavers. It kept looking at me, still snorting now and then.
Then one beaver swam back to the lodge taking a route that appeared to me to be a bit closer to the otter.
When the beaver got between the otter and the beaver lodge, it turned and swam toward the otter.
The the beaver lunged and the otter jumped into the water.
Here is a short video of the attack.
The beaver slowly went back into its lodge. The otter surface through a hole in the ice some 30 yards away, and then swam back to get a closer look at me (as if I had anything to do with it!) It was careful at first to keep behind some dead stumps.
I shared this post on a Facebook page maintained by friends of beavers and some found it hard to accept any aggressive tendencies in a beaver. One wrote: "That's called a 'false charge' and is a common way that beavers scare off a predator or other potential threat. Notice that the beaver never actually touched, or even came very close to the otter. Not much of an attack."
Modern wildlife studies are a cacophony of labels most of them phony like "false charge." Using words like that to describe what an animal does assures humans that no matter what an animal does it won't challenge our preconceptions. I gave up reading books that invent false notions like false charging beavers to protect pet theories of animal behavior. I spend as much time as I can trying to watch animals in the wild. What I saw that day in March, I've never experienced again though I have dutifully gone out to the ponds during every March thaw since and in 2010 saw four otters, two beavers, and two geese eying each other. But nothing like what I saw that March.
Here is a very long video of that memorable afternoon. I have never had a longer encounter with an otter. The beavers were too hungry to notice me.