Bad news

Someone has stolen my camera.

There are of course, pictures of the thief or thieves in action. I can only hope that they will be sent to the police.

Anybody know how to do that crowdfunding thing.......

The dam bigger than ever, and interesting raccoon behavior

The dam. 23 March 2014

It's hard to tell from this photograph, but the dam is longer, and I think a little higher than it has ever been. Some water had been flowing around the dam on the the east side. The dam is now about 10 feet longer in that direction, and almost rises over the bank.

The dam on the west side is also longer, but not as dramatically as on the other side. The water level also seemed higher than I recall. That may have something to do with spring ice melt.

Another view of the dam. 23 March 2014.

The beavers also built up the entrance to their den. There had always been some sticks around it, but only a very few. Now there is a real structure, and the hole in the stream bank is completely covered. I wonder if that has something to do with preparation for birth. But then again, I may be anthropomorphizing.

Most sources say that we can expect to see the kits born in May or June.





Meanwhile, as you can see below, they are still active, and still cutting trees, eating, and building their dam.

In several of the videos, raccoons appeared, Including a video of two raccoons together. As you may know, raccoons eat almost everything they can get their paws on. They eat insects, worms, fish, crayfish, nuts and bird eggs, among other things. Their territory size varies, but in rich habitat such as Cromwell Valley Park seems to be about 2/10th of an acres.  While looking up some information about raccoons, I ran across a great explanation of their behavior. One researcher observed that "typically you'll find 10 to 15 percent who will do the opposite" of predicted behavior. I guess those animals didn't read the manual.

Get outside and play.

More later.

The dam was breached, the dam was repaired, and the camera missed it all

The dam. 23 February 2014.

As you can see in this photograph, melting snow combined with some rain, overwhelmed and breached the dam.

I thought it might be fun to see if I could capture some videos of the beavers repairing the breach. So, I put the camera in a location overlooking the breach and aimed it in such a way that I thought would do exactly that. I was exactly wrong.

Apparently the beavers were able to swim up to and repair the breach without triggering the motion detector on the camera.

The dam. 9 March 2014.

Four videos are posted below.

The first two are fun to watch. You'll see that a groundhog likes to use the dam as a bridge to cross Minebank Run. With the dam intact, that's one happy groundhog. With the dam breached it's not such a happy critter.

The third video shows one of our beaver pair swimming about in the pond.

The fourth shows a pair of ducks swimming about in the beaver pond.

Which reminds me of a fact revealed by a study in Yellowstone National Park.

"Increases in beaver populations have strong implications for riparian hydrology and biodiversity –Wyoming streams with beaver ponds have been found to have 75 times more abundant waterfowl than those without."
http://oregonstate.edu/ua/ncs/archives/2011/dec/yellowstone-transformed-15-years-after-return-wolves

More later.

A breach in the dam

The dam. 19 Feb 2014.

I checked the dam twice recently. Once on the 19th, and again today. I'm not surprised, but a little sad, to say that the dam has breached from the heavy snow melt and rain combination.

You can see in the second photograph that the middle section of the dam has breached.

I'll keep an eye out to see how long it takes to repair the damage.

The dam. 23 Feb 2014.

A field of stumps regenerating.

On the 19th, I happened to walk around the old dam site from 2011. That particular dam has been washed out and abandoned some time ago. I was on the right bank of the run, where many trees had been cut down and presumably killed by the beavers. 

Happy news. 

As you can see in these two photographs, most of the trees chose not to die, but rather to regenerate.  You can find an interesting article about the process here: http://www.adirondackalmanack.com/2013/06/adirondack-forestry-stump-sprouting.html.

Stump sprouts.

Meanwhile, a couple videos of the ubiquitous fox and also a raccoon. Hope you enjoy them.

More later.

I saw a Bluebird today

I checked the dam yesterday and noticed something interesting.

A section of the dam had failed. The bank on the left side of the stream failed. It was incised already, and seems to have failed. the failure point was just downstream from the dam, and caused about seven feet of the dam to collapse.

The beavers have wasted no time in repairing the dam. You can see the repaired section in the foreground of this picture. The sticks are newer and less weathered. You might also see that there are no leaves stuck in between the sticks as there are in the older section of the dam.  Those leaves are an important part of the benefits of beaver dams. They provide food for insects. And those insects provide food for trout and other fish. And trout provide sport and food for humans. In one study, winter survival rates for salmon and trout was 2 or 3 times greater in streams with beaver dams than streams without beaver dams. (www.martinezbeavers.org/wordpress.)

Here you can see an earlier video of a beaver carrying leaves to the dam.

I've never been successful in capturing the beavers working on the dam. But I'm trying again. I hope to get some video of the dam repairs. Wish me luck.

Meanwhile, the usual suspects are active around the dam: beaver, deer, fox, squirrels, people, pet dogs, and raccoon.

And an Eastern bluebird. That's a nice reminder that spring is coming.

Soon the bluebird boxes in the park will be humming with activity.

More later.

Animal magnetism--literally (and a note to some young fans)

The dam. 20 January 2014

The dam is in good shape. Maybe better than any of the four  I've seen in the last two years. Let's hope it holds.

You all may recall the neat videos of a fox hunting that I captured last month.

You can see the sequence of three videos here.  

If you look closely at the third video, you can just see the prey escape.

The fox failed to catch its prey. Talking with various friends, the question arose; how often are fox successful in pouncing. Good question, isn't it?  

The answer depends, amazingly, on which compass azimuth they are aligned with.  It seems that foxes have a magnetic sense.  If the fox is facing north to northeast, it's successful in 73 % of its pounces. Facing other directions, the success rate is 18%.

A quick search revealed other examples of animals having some sort of internal compass.

• Water birds are most likely to land in a north-south line.
• Dogs are most likely to excrete while on a north-south axis.
• Migrating birds have a compass map of the world, and use it to know where they are.
• Cattle and deer tend to browse on a north-south axis.
• Loggerhead Sea Turtles have a magnetic sense and use it to navigate.
• Sockeye Salmon have a magnetic sense, and use it to return to their spawning grounds.
• Spiny lobsters appear to have a" magnetic map" that they use to know their location in the world.

That's what I found with just a quick search. There are probably other examples. It seems pretty clear that many animals have the ability to sense earth's magnetic field.

And this sense allows them to do more than recognize a north-south line. Every place on earth has a unique magnetic map; a map that some animals appear able to recognize.

So, after reading this, maybe you are curious to know what direction the fox was aligned when it failed to catch dinner?  Just a little bit south of west. 

Failure.

Fascinating.

Hey, Jack, I'm not making this up myself.  See below for some references.

And a special note to some young fans who left me a message via camera on 19 January 2014 at 2:18 pm. I do read my comments; and I did see yours. I also enjoyed your art installation. It was great. I look forward to your next one. I'm glad you're enjoying the blog; really glad.

More later.

"Pathfinders", by Doug Stewart., February/March issue of National Wildlife.

http://rsbl.royalsocietypublishing.org/content/early/2011/01/06/rsbl.2010.1145.full

http://www.nytimes.com/2012/04/27/science/study-sheds-light-on-how-pigeons-navigate-by-magnetic-field.html?_r=0

http://www.birds.cornell.edu/AllAboutBirds/studying/migration/navigation

http://www.pbs.org/newshour/rundown/2014/01/dogs-poop-in-alignment-with-earths-magnetic-field-study-finds.html

http://www.frontiersinzoology.com/content/10/1/38

http://news.nationalgeographic.com/news/2008/08/080825-magnetic-cows.html

http://www.newscientist.com/article/dn20172-loggerhead-turtles-have-a-magnetic-sense-for-longitude.html#.Ut1UmxAo6M8

Snug as a bug in a rug

the dam and ice-covered pond. 4 Jan 2014.

I had a chance to check the camera and the dam last Saturday. There was snow on the ground, and I was
looking forward to seeing lots of track. I thought I might learn a thing or two about animal activity around the beaver pond.

I did learn a thing or two--just not what I expected.

What surprised me was that there was very little track of any sort in the area, and absolutely no beaver tracks.



I assume that means the beavers are doing what beavers do. That is, staying under the ice where they are safe from predators. They've already stashed a lot of food under the water, in the form of sticks. The entrance to their den is under water so, again, no predators can get at them when ice forms on top of the pond.

This drawing gives shows you how it works, and saves me a thousand words to boot. Can you imagine how our beaver family is happily and safely whiling away the winter under the protection of the ice. They've got a house, food, shelter--everything but high def TV.  And no predators can get at them.

While scouting around, I saw a Great Blue Heron. Probably, it's the same one the camera picked up in this video on the 30th of December.

This is not the only Heron that has benefited from a beaver pond. See this link for another story of the symbiosis of beaver ponds and birds. http://www.treehugger.com/natural-sciences/busy-beavers-save-blue-heron-nesting-ground.html





More later.