Do nutria build dams like beavers do?
December 20, 2006 8:56 PM   Subscribe

Do nutria (aka coypu) do the kind of water works that beavers do?

There's a stream that runs through the backyard of my apartment complex. There's water in it all the time, but in the rainy season after it rains it actually runs quite a lot of water, though there isn't really any flooding risk. I can see it very clearly from my deck. About a hundred feet from me there's a place where there's some rapids, and about three weeks ago two men from the county in waders were in there working, hauling out all kinds of branches and sticks which were piled up at that one point, and then using mattocks to dig out mud and dead grass. They just piled all of it up on the bank, and didn't haul it away.

Since then, every night the neighborhood dogs have been barking their heads off, and every day when I look out, more and more of the branches have moved back into the stream, in exactly the same place, all tangled together and anchored nicely. My landlady told me that it was beavers.

But my brother said he thought it was nutria. I know there are nutria around here; I've seen them. (What I saw weren't muskrats because the tails were round and they were too big.) And somehow it does really seem a bit implausible that there are beavers doing their civil engineering thing in the middle of Beaverton, Oregon, which is where I live, the city name notwithstanding.

The Wikipedia article on nutria doesn't mention anything about dam-building, and neither does Encarta Encyclopedia. The Wikipedia article on beavers says that beavers and humans are the only large species known that deliberately change their environment for their own benefit; it doesn't include nutria in that list. But you know how that is.

Could it be nutria? Or are beavers the only ones who do that sort of thing?
posted by Steven C. Den Beste to Science & Nature (10 answers total)
As someone with deep family roots in the nutria-rich parts of the Gulf Coast....I've never heard of nutria building dams, or anything else.
posted by gimonca at 9:01 PM on December 20, 2006

Beavers dam, nutria dig.
posted by Pollomacho at 9:03 PM on December 20, 2006

Y'know, there are actually beavers in Beaverton.

I was at a restaurant in the area recently that had a stream running through it's back property, and they had protected the young trees with construction cloth to prevent the beavers from gnawing upon them.

Sounds like beavers to me.
posted by Aquaman at 9:36 PM on December 20, 2006

Aquaman, it's probably a different section of the same stream; thanks for that information.
posted by Steven C. Den Beste at 9:40 PM on December 20, 2006

Nutria eat the vegitation and dig tunnels into the water banks. If anything , they undermine and destroy the river and canal banks, that's why there is a bounty on them in coastal Louisiana.

Beavers are cute, nutria look like huge rats (size of cats), with long orange teeth.
posted by JujuB at 10:16 PM on December 20, 2006

We have a pair of beavers in our stretch of Fanno Creek, so my guess is yep, you too are infested with beavers. Be on the listen for the loud tail-slap.

Our dogs are also obsessed.
posted by nenequesadilla at 10:30 PM on December 20, 2006

You know it's sad, but I actually had to look up mattocks. I had never heard that term for pickaxe before.

Beaver pelts may be nicer, but nutria is better eating.
posted by Pollomacho at 11:25 PM on December 20, 2006

Look for the nipples high up the sides, above the waterline. If you see nipples, it's nutria.
posted by plinth at 4:34 AM on December 21, 2006

Beavers also look like huge rats. Because they ARE huge rats.
posted by unSane at 12:51 PM on December 21, 2006

I don't know if anyone cares, but here's an update: the men from the county came again, and cleared all the branches out of the stream again. And this time they hauled it all away. (Aaah! That's no fun!) But I went out yesterday and took a look, and there are a couple of branches in there again. I think the beavers haven't given up; it's just that they're having to haul their stuff from further away now.
posted by Steven C. Den Beste at 5:07 PM on January 10, 2007

« Older How do we split profits for our startup?   |   English translations of Control Machete lyrics... Newer »
This thread is closed to new comments.