The mind of a beaver

[Solitary]

This is from Goose Pond:

Do beavers actually think about the best way to fell a tree? Do they understand what they are doing or do they just feel the urge to gnaw? I'm asking because I wonder why the beaver would almost finish felling the tree and then start a second cut just above it.

Clearly I have too much time on my hands to wonder about this stuff.

 

[Grumpy]

Good question (and I don't know the answer). I've seen trees gnawed by beavers in a spiraling auger pattern. Go figure that one.

G.

 

[Silverfox]

perhaps it has to do with how tall the beaver is??

obviously the work of a regular size beaver and his friend the midget....

 

[DougPaul]

perhaps it has to do with how tall the beaver is??

Or the depth of the snow pack...

Doug

 

[Mark Schaefer]

Doug and Silverfox got here first. Beavers continue to grow in size throughout their life so size is probably a factor along with differing winter snow depths.

Beavers must gnaw. It is not an option. Their four front incisor teeth continuously grow throughout their life. They would die if they did not gnaw. The back of the incisors are softer than the tips and break down faster while gnawing. If the beaver did not gnaw the teeth would grow through his jaw, and eventually the beaver would not be able to open his mouth.

 

[Grumpy]

Or the depth of the snow pack...

I don't think snowpack had much to do with the gnawing patterns shown in the picture above. If it did, the upper and lower gnawings would show some noticeable differences in weathering of the exposed wood, which I don't see in the photo.

It is interesting how the bark has been stripped away with gouge-like strokes by M. Beaver's choppers. I wonder if what we are seeing here is nothing more (or less) than a feeding-gnawing pattern reflecting a one-stop answer to M. Beaver's need for nourishment and need for gnawing to keep the growth of those teeth under control.

G.

 

[Kevin Judy and Emma]

Gnawing

Mark hit the nail on the head with the gnawing to wear down the teeth. It's not a choice but a matter of survival, for the reasons stated in his post.

KDT

 

[bikehikeskifish]

Besides keeping their teeth short, they actually do use the logs for building dams, and they eat the bark of several trees (preferably poplars.) A few years ago I worked right on the Merrimack River in Andover, and the beavers would drop the poplars, and carry off the tops where it was tender. I learned they store them on the bottom of the river for consumption in the winter. I spent a few hours with a chainsaw cleaning up the trail so I could mountain bike and XC ski, and when I lowered a tree close enough to the ground (it had fallen, and was leaning on another tree), within 48 hours the top had been "stolen"

Tim

 

[Karst]

Beavers must gnaw. It is not an option. Their four front incisor teeth continuously grow throughout their life. They would die if they did not gnaw. The back of the incisors are softer than the tips and break down faster while gnawing. If the beaver did not gnaw the teeth would grow through his jaw, and eventually the beaver would not be able to open his mouth.

Saber-toothed beaver?

 

[sleeping bear]

The beavers IMAX movie is awesome. They squeak.

 

[forestgnome]

Nice picture of life!

happy spring

 

[Hillwalker]

Beaverworks

If you want to take a nice hike into a very underused area with a beautiful wild gorge, take a day hike into the Moriah Gorge. The gorge is incredible, and after you pass the gorge on the Moriah Brook trail you will cross over and walk among some truly gigantic old Beaver dams which are now in full woods. At first look the terrain looks just different until you realize that you are standing in the middle of very old beaver works that may be hundreds of years old.

After the gorge and on the way in, when you cross the upper Moriah Brook look for the old iron rods sticking out of the ledges. This former old logging railroad trestle was the location of one of New Hampshire's biggest logging railroad disasters. There are parts of the railroad engine that exploded just after reaching the crossing scattered around in the woods if you look.

There are also quite a few native Brookies living up above the gorge, and in it if you have the ability and nerve to attempt the climb down into it. Bring climbing ropes and Jumars along with your trout gear. Unusual mix eh?

 

[dentonfabrics]

A Beaver Tale

I'm lucky enough to have natural areas all around my house. I've got a large bog a half-mile to my east, another bog a mile into the woods behind my house, and a preserve a half mile down the road to the west. This preserve has a dam and lodge built, which creates a beaver pond of about 2-3 acres and is home to birds (hawks and herons) and other critters.

About two years ago, I came across an injured beaver in my driveway. He was sitting on his tail, obviously injured, probably after a run in with a car. My theory on how this happened is that the beaver was injured commuting to work. I found out that when young beavers reach a certain age, they are forced out of the family lodge to start it's own. I think that this beaver was hurt "commuting" from his home at the preserve area to his new lodge which he was building at the bog east of my house. I have read that this is typical beaver behavior, to live in it's existing lodge while it is building another.

There are a couple of fallen trees and a couple of half gnawed trees at the east bog to support this theory, and those gnawed trees are still intact, unchanged from how they were in 2006.

I guess the point of this story is that it's interesting to read clues from your surroundings and apply what knowledge one has of nature to interpret how nature works and how animals live. I might be wrong in my conclusions about my injured beaver but I'm really grateful to live in an area where I can be exposed to the workings of nature.


bob

 

[Mats Roing]

Does anyone know the reason why the giant beaver died out about 10,000 years ago?

It was similarly shaped as today's bears but their teeth were a bit different with vertical "stripes" on them:

Here is a model with a person next to it for comparison:

 

[DougPaul]

Does anyone know the reason why the giant beaver died out about 10,000 years ago?

They ran out of big trees?

A number of large mammals have died out in the past. Don't know why--probably a number of causes.

Doug

 

[Chip]

Does anyone know the reason why the giant beaver died out about 10,000 years ago?

Hobomock, of Sleeping Giant, Hamden Ct fame killed him.

 

[Grumpy]

Besides keeping their teeth short, they actually do use the logs for building dams, and they eat the bark of several trees (preferably poplars.) A few years ago I worked right on the Merrimack River in Andover, and the beavers would drop the poplars, and carry off the tops where it was tender. I learned they store them on the bottom of the river for consumption in the winter. I spent a few hours with a chainsaw cleaning up the trail so I could mountain bike and XC ski, and when I lowered a tree close enough to the ground (it had fallen, and was leaning on another tree), within 48 hours the top had been "stolen"

Tim

Interesting observations and story.

Beavers do prefer the aspens and cottonwood trees, from what I've observed. They'll pass right by other species and fell whole stands of the preferred trees if left to their devices.

Not all beavers build dams, especially on larger streams with good currents. I've heard some people refer to the non dam builders as "bank beavers." They still consume their share of trees, though.

G.

 

[Solitary]

We have met the enemy and he is us...

Does anyone know the reason why the giant beaver died out about 10,000 years ago?
[/IMG]

I think it is the book Guns, Germs, & Steel where the author - Jared Diamond - points out that virtually all large North American mammals went extinct just about the same time that humans arrived across the Bering Strait.

As Pogo said, "We have met the enemy and he is us."

Here's a link to extinct megafauna
http://www.kokogiak.com/megafauna/

 

[Mats Roing]

virtually all large North American mammals went extinct just about the same time that humans arrived across the Bering Strait.

The humans passing the strait must have been hungry........and saw a bunch of giant walking steaks.......makes sense.....

 

[bikehikeskifish]

Interesting observations and story.

Beavers do prefer the aspens and cottonwood trees, from what I've observed. They'll pass right by other species and fell whole stands of the preferred trees if left to their devices.

Not all beavers build dams, especially on larger streams with good currents. I've heard some people refer to the non dam builders as "bank beavers." They still consume their share of trees, though.

G.

True -- in this particular case, this was a "river beaver" and they don't build dams -- just take the tender tops for food. At the tree farm, they did use both parts -- the logs / limbs for dams and the tops for food.

My mother-in-law's husband does firewood on the tree farm property (not to be confused with the river), and after cutting the aspens, he'd bring the tips to the beaver pond. The next day, they'd be gone. After a few days, the beaver was waiting for him at the appointed time.

Tim