April 2021

Bronson Creek Moves to Traditional Channel

Two years ago. All the water flows thru Bronson Creek, the drainage ditch used to divert the water away from pre-pioneer wetlands. The field is dry.

Current photo. Most of the water now flows thru wetlands. Some water still flows thru the old Bronson Creek channel.

My brother and I share a drone. To get the recent aerial view of the wetlands I sent the drone as high as the software would allow. I could no longer see the drone. Then I flew the drone over the field taking pictures straight down every so often. I had to stitch the photos together with Photoshop. It was spooky flying the drone without being able to see it.

Having the "wetlands" be a real wetland, rather than a horse pasture, greatly increases the plant diversity and makes habitat for many more plants and animals. This transformation only happened after people stopped removing the beaver dams on Bronson Creek.

Toshio Sakuma took the above photo of beaver activity. In this photo I see ten trees that have been cut down. On the ground are large wood chips.

The beaver stands on hind legs while cutting the tree. Note how high the beaver can get. Also, notice that the part of the tree that has been cut down is not on the ground. The beaver has cut each tree into sections and then hauled everything away. The bark is eaten. The de-barked sticks are used to build dams, a lodge or are sometimes just left laying around.

This patch of willow trees is in an area that has been abandoned for the last 40 years, so it seems. Before being thinned by the beaver it was hard to pass thru this area. Many of the cut willow trees will continue to live. You can see branches below the cut on the tree in the lower left of the above photo. Those branches will grow into a bushy willow.

Toshio also took this photo of the beaver lodge on the left. The lodge looks like a pile of muddy sticks. The beaver enters this lodge thru an underwater tunnel. It looks like the beaver also has a path to the top of the lodge.

Audubon Vermont has a good article on beavers that shows a diagram of a beaver lodge: https://vt.audubon.org/news/busy-beavers

When we look at the wetlands we see ground that is almost level stretching from bank to bank. When I go to Death Valley I see places where water has carved deep V-shaped valleys right thru rock. We should wonder what geological process causes our wetland valley to be wide and flat while the washes at Death Valley are narrow and deep.

Evidence from many sources suggest that it is beavers that have shaped our creeks and wetlands. Beavers have been here for millions of years, erecting dams that hold back flood waters. Behind the dams silt collects, eventually changing the beaver ponds into meadows. Over time the creeks change course and new dams are erected. This system keeps the wetland valley from constantly eroding material and becoming a V-shaped valley with steep sides.

Although the beavers do this for their needs the ponds and meadows provide much more habitat for other species than a valley etched into the bedrock with steep banks.

Trail Cam

For the last week the Trail Camera (in the photo on the left) was pointed at a beaver dam. The photo on the right shows the dam. Water is flowing from right to left and goes over the dam.

This position for the camera shows animals going up or downstream. A disadvantage with this setup is that the camera moves when the wind blows or when birds land on the branch holding the camera. This caused many extra photos to be taken.

The date and time are included at the bottom of the photograph.

The night of April 4, 2021 seems typical: This sequence of photos shows the activity at this spot on the beaver dam. The dam consists of two or three sections and we only see the activity on this section. So, not all of the traffic goes past this spot.

The photos are in chronological order.

At 10:23 PM a beaver goes downstream.

At 11:31 PM a beaver goes upstream.

At 11:49 PM a beaver goes downstream.

A second photo at 11:49 and the beaver seems to have moved forward a small amount. This is probably the same beaver that has paused for some reason.

An hour later the temperature has dropped to freezing and a beaver goes downstream. Same beaver?

Eight minutes later a beaver goes downstream. The beaver must be going upstream somewhere else?

Two and a half hours later a beaver goes upstream. The temperature has dropped to 27F.

But look! There are two beavers going upstream.

Is this the second beaver? Or, perhaps, a third beaver?

The second beaver could have paused. Or is this a fourth beaver? Hard to tell.

It does look like the second beaver is just waiting.

Two hours later and a racoon walks over the dam.

The sun comes up, the temperature warms up to 61F, and a nutria visits the dam in the afternoon.

In this next sequence, about an hour after the nutria visit, a small animal triggers the camera. The animal blends in with the brush and is very difficult to see.

The arrow points to the body of the animal.

In this photo the arrow points to what looks like a wing.

This activity continues for 27 minutes.

Then a male mallard duck comes walking upstream. The arrow points to where the animal is.

Something attracts the attention of the duck. The animal is flying away. I can tell this only by comparing this photo to the previous one. The mystery animal was a bird.

The duck flies away. A half hour later this nutria shows up. It is hard to see being partly obscured by brush. This appears to be unrelated to the earlier events.

The next day at about 2 PM this black colored bird showed up.

Although I can't see a red patch on the wing I know that red-wing blackbirds are in the area.

Then this camouflaged bird showed up. This is the color of the female red-wing blackbird.

One last photo of this bird. Then, no more bird activity at this location.

TheCornelLab says this about red-wing blackbird nests: "Red-winged Blackbirds build their nests low among vertical shoots of marsh vegetation, shrubs, or trees. Females choose the nest site with some input from the male. Typically, she puts the nest near the ground (or water surface in a marsh), in dense, grass-like vegetation such as cattails, bulrushes, sedges, and Phragmites in wetlands; goldenrod, blackberry, or willow and alder trees in uplands; and wheat, barley, alfalfa, and rice plants. "

Perhaps these birds decided that there was too much activity at this location for a nest.