Bear Tree?

[Mohamed Ellozy]

A few days ago, while walking up Tripoli Road, I noticed a dead tree with serious scratch marks. Today I finally remembered to take my camera with me.

A closer look:

More pictures here.

Google led me to a Bear in the Woods blog post with a more extreme example.

 

[erugs]

Interesting. Do you think they were recent? (Were there any tracks?) (Did you see any bear hair?) Did you smell any bear-type smells or see bear scat?

 

[Mohamed Ellozy]

I did not get close enough to look for hair or scat, but it must be recent. I walk by this location at least once a week, and the tree cannot be missed. First saw it about ten days ago.

 

[rup]

What about the condtion of the snow cover around the ree? Tracks??

 

[MikeM]

Looks like the work of a pileated woodpecker on a poplar tree, although a bear sounds more exciting!

 

[marnof]

Looks like the work of a pileated woodpecker on a poplar tree, although a bear sounds more exciting!

I was thinking pileated wp as well, considering it looks like a dead tree that might not bear the weight of a bear.

 

[Mohamed Ellozy]

I though woodpeckers tended to drill holes like this:

Also the shredding at the edges looks like the work of claws.

OTOH I agree that the tree did not look very solid ...

 

[erugs]

I thought the shredding was more like claws than bill. Not the rubbing you see on some trees. Would some smaller animal do shredding like that? Would a bear not put its full weight against a tree? Maybe trees are stronger in winter when any moisture in them freezes?

 

[marnof]

Not sure where I saw it, but I've seen examples of woodpeckers stripping bark off trees... maybe they pull the bark off first then peck at the promising areas?

 

[Stan]

How high up on the tree did the scratch marks go? I don't know that bears climb trees to scratch but perhaps it found a rich supply of bugs and was digging for more. BTW, bears don't really hibernate, they "den" from my understanding and, when the weather is warm, might come out briefly but they're still drousy and generally don't start eating right away. It could have been a bear last fall gouging up before denning.

P.S. Bears do leave "sign posts" like this, especially males, to mark their territories and an adult bear could scratch up to 6-7 feet high.

 

[DSettahr]

Are you sure it's a bear tree? It looks more like a bare tree to me...

 

[gaiagirl]

There is certainly something new to see and learn every time I am out in the woods, so I wouldn't swear to it, but this does not appear to be the work of a black bear. Bears climb and/or scratch for a few reasons and none of them fits here: they climb beech trees predominantly, to get access to nuts; they climb to avoid other bears, humans and occassionally predators (cubs, mainly); they scratch specifically to mark trees for scent and also literally to scratch their bodies --- I have seen this typically on red oak, which supposedly has oils that act somewhat medicinally. This tree just doesn't fit any of those profiles. Also, when bears do climb, I have never seen a tree end up shredded like this. But even more to the point, this tree doesn't look capable of holding the weight of much, let alone a black bear. I would agree that this is probably the work of pileateds, though I can't say I've ever seen damage exactly like this before.

 

[nartreb]

I think the tree is solid enough to hold at least a cub, though parts of the tree look like the bark has been pried sideways and/or upward, which might be difficult for a climbing bear to do with claws - but maybe it used jaws too, or maybe the close-up was taken close to the ground.


Here's another odd animal behavior:

There's no question as to the culprit - tooth marks and tracks are very clear. What confuses me is the tree in the foreground - it's a several yards *upstream* of the pond (in background), with, as you can see, a number of obstacles between it and the pond. I can't imagine a lone beaver or pair of beavers dragging this tree to the water, so why bother felling it? Hoping for big floods to carry it down in the spring? Clearing the canopy so more yummy willows can grow? If the latter, why only target birches?

 

[una_dogger]

Agree with other - pileated woodpecker. If the tree is spongy and rotten, it could shred easily. Could also be moose/deer browse marks.

 

[marnof]

I can't imagine a lone beaver or pair of beavers dragging this tree to the water, so why bother felling it? Hoping for big floods to carry it down in the spring? Clearing the canopy so more yummy willows can grow? If the latter, why only target birches?

Birch bark is one of their favorite things to eat. I'm puzzled by their choices of trees to forage on as well--sometimes it seems pretty bizarre. There are homeowners on the Connecticut River near Haddam that have had to wrap wire fencing around their over 2ft diameter oaks to keep the beavers from damaging them, even felling some lesser ones with no obvious use for them in lodge or dam construction. Maybe it's just a good workout for the teeth!

 

[nartreb]

Marnof - there are actually two downed birches in the picture - neither of which has been stripped of bark. A third birch is under attack, with a pile of woodchips at its base and some easily-reached bark still intact.
It really looks like the beaver is positioning logs to dam the *inlet* stream.

I bet birches are easier to chew through than oaks or maples, which were the dominant trees nearby other than the stand of conifers (hemlock?) you see in the background.

 

[marnof]

That makes sense, nartreb, since the birch is softer than the oak and maple, and tastes better than the pitchy hemlocks and other conifers. And once they're felled, they are easier to browse on and/or use for construction projects.

 

[DougPaul]

There's no question as to the culprit - tooth marks and tracks are very clear. What confuses me is the tree in the foreground - it's a several yards *upstream* of the pond (in background), with, as you can see, a number of obstacles between it and the pond. I can't imagine a lone beaver or pair of beavers dragging this tree to the water, so why bother felling it? Hoping for big floods to carry it down in the spring? Clearing the canopy so more yummy willows can grow? If the latter, why only target birches?

The beaver may have felled to tree to get at the smaller branches above. They can be cut off and dragged into the pond for later snacking. (Beavers store branches under water for a winter food supply.)

Doug

 

[Jason Berard]

I always though Yellow Birch was quite hard and I use it for firewood often. I came across this chart which lists btu's per cord. I guess it IS softer, but not by too much. Maybe the beaver was taking down these trees to get at the smaller branches for food? I like the "dam the inlet" idea, too. I believe beavers often move upstream when their food is running low in a particular dammed area? Anyway, here is the chart for btu's per cord (in millions), which relate pretty well to density, I think.
Northern Red Oak 24.0
Sugar Maple 24.0
White Oak 24.0
Yellow Birch 21.8

Edit: Doug beat me to it!

 

[una_dogger]

I think the tree is solid enough to hold at least a cub, though parts of the tree look like the bark has been pried sideways and/or upward, which might be difficult for a climbing bear to do with claws - but maybe it used jaws too, or maybe the close-up was taken close to the ground.


Here's another odd animal behavior:

There's no question as to the culprit - tooth marks and tracks are very clear. What confuses me is the tree in the foreground - it's a several yards *upstream* of the pond (in background), with, as you can see, a number of obstacles between it and the pond. I can't imagine a lone beaver or pair of beavers dragging this tree to the water, so why bother felling it? Hoping for big floods to carry it down in the spring? Clearing the canopy so more yummy willows can grow? If the latter, why only target birches?

While backpacking in Colorado's La Garita Wilderness many summers ago - just below timberline along a creek in a long stretch of aspen glades, beavers had busy not only felling trees a considerable distance from the stream, but also assembling small woodpiles here and there. The dam network was extensive - a series of dams in fact, stretching out ~ 1/2 mile along the stream!

Most industrious beavers I've ever seen!

I'm not sure why the beavers in Nartreb's photo selectively logged birches - however, I suspect perhaps it has to do with their nutritional value, since IIRC, beavers eat wood.