Monday, November 18, 2013

The Beaver Wars: round ten to the beavers

It's a long story, going back to 2008. (Previous posts: May, 2009; November, 2011January, 2012March, 2012; November, 2012.)

History to date:

We first saw signs of the Cougar Creek Park beavers in 2008. They were colonizing the newly-landscaped lagoons, and had dammed the lower creek outlet. The next year, they had dammed the inlet as well, creating a small pool on the upper level.

The city (Surrey) has objected; this was not in the official plans. So they've fenced and wired the trees, sometimes reinforcing them with wired-on chunks of wood. They've removed the dams, they've caught and killed a male, they've cleared trees off the banks, completely removing a shady stand of evergreens; the resulting erosion has turned the upper end of the original pond into a muddy slough.

The beavers shrugged off their losses and went back to work.

By November of 2012, the family had succeeded in damming the upper creek, filling in what had been a wasteland with a slow, muddy trickle down the centre. It made a pretty duck pond, striped with reflections from the alders around it, over patterns of green and gold animated by swimming, dabbling ducks.

Map of ponds, November 2011, with the dammed upper creek marked in blue. The pond now extends to the bridge at the far right.
In January, 2012, the dams and the new pond were gone. By that March, the three dams were back; the upper pond was filling again. Mallards, wigeons and mergansers were busy in the new feeding ground; as usual, a heron was hunting along the edges.

I took my grandson down to the park to show him the beaver dams in September of that year. We were disappointed; not only had the city removed all the dams, but they had gone into the wasteland with machinery and scraped off much of the vegetation, leaving an oozing, muddy mess, scattered with garbage. (So much for the much-advertised "Releafing Project".) A lonely pair of ducks patrolled the lower lagoon; nothing else, not even the heron.

We went back last November. (I calculated this as Round 8.) Now there were three good dams, and a lodge. The upper pond covered the machine scar nicely, and they'd built another dam at the top, making a new, third pond. The ducks were back.

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2013:

This spring, we found the upper pond area scoured clear again. By summer, there was a start on a new dam, near the bridge. It didn't last; the next time we visited, the creek was trickling over bare mud again. There was no sign of beaver activity anywhere. I wondered if they had finally given up.

The beaver is a stubborn animal.

I took a friend to the park last week to look at ducks. And found the beaver ponds expanded once more, swallowing up most of the space between the schoolyard and the fenced houses on the map above.

The ducks are happy with twice the water to dabble in.

The newest dam, raising the water level a couple of feet. Lots of good-sized lumber in there, probably incorporating trees the city had felled.

This latest project is quite ambitious; the beavers have cut down some large trees, red alder wood for construction, the juicy bark and cambium for food.

Two trees, the smaller one gone to the dam. The other will have to be cut in small chunks if they plan to use it for building.  If not, it has a whole season's worth of groceries under the bark.

Toothmarks in wood, cambium, and grey-green bark.

Part of the new pond.

In earlier episodes, the lodge was usually built in the lower lagoon. (The small, squarish one in the map above.) Here, it was highly visible to anyone walking on the paths, crossing the bridge, or in the back yards of the houses to the south. It never lasted long.

Someone, some beaver, has been thinking. The latest lodge is well hidden.

In the new pond, water has overflowed the previously established banks; much of the "bush" - salmonberry, elder, Indian plum, ferns and the inevitable blackberry canes - has its feet underwater. We walked around from the upper end, as far as we could go without wading. And hidden between trees and bush, we found the lodge.

It's a big lodge, high and long. This was as close as we could get. I think that's cattail growing on the far side; a new addition to the vegetation here.

And I still haven't seen the beavers themselves.


5 comments:

  1. Anonymous7:49 am

    I love their tenacity and artistry. Wonderful post!

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  2. It looks like Broad-leaved Cattail (T. latifolia?)

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  3. Beaver don't seem to need trees - there are none around the pond here, but the beavers keep coming back, every time the city catches the old ones. I saw a beaver on Saturday morning, across the pond, swimming along amongst the geese. Nothing else could have been that size, and so low to the water. I have no idea where they build their lodge, unless it is in the marsh...

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  4. I am curious that you have not mentioned any public effort to make the city staff stop harassing the beavers. Isn't there any interest?

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  5. Fred, As far as I know, that's it.

    Gary, I have not seen any interest in letting the beavers stay. There was an angry protest when one was killed, back in 2008.

    "Surrey hires a trapping company that catches and kills an average of 14 beavers per year in the city, said Vincent Lalonde, an engineering department manager."

    "Surrey Mayor Dianne Watts has declared her opposition to killing beavers."

    These two quotes are from discussion of the protest in 2008. As far as I know, there has been no complaint since.

    We talked to one of the neighbours; he wanted them shot or removed, because, he said, they were dangerous; they could drop a tree on top of a kid. (As if they'd be working while the kids were playing.)

    I looked up the city's animal control page on beavers. It is internally contradictory, talking about benefits in one paragraph, removal tactics in the next.

    "Beavers are nature’s engineers. Their damming creates wetlands and ponds which are habitat for fish, water birds, amphibians and a host of other plants and animals. Unfortunately, the return of the beaver had created management issues on private and public lands. The beaver’s need to dam water causing extensive flooding and can damage crops, property and grazing lands. - See more at: http://www.surrey.ca/community/3651.aspx#sthash.P2ihjHeS.dpuf"

    ReplyDelete

I'm having to moderate all comments because Blogger seems to have a problem notifying me. Sorry about that. I will review them several times daily, though, until this issue is fixed.

Also, I have word verification on, because I found out that not only do I get spam without it, but it gets passed on to anyone commenting in that thread. Not cool!

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