Black bears stripping tree bark

[Okanagan]

Black bears strip the bark from trees and eat the inner soft layer just under the bark.  In the photo above it is a western red cedar tree with bark stripped off.  The horizontal scratches are where the bear's claws pried under the outer bark and pulled it off.  The vertical marks are from the bear's teeth scraping and eating the inner soft layer just under the bark.

Photo below is of two trees out of five in a row along the road side that a bear had worked over a day or two before.



Below is a pic of a fir tree (I think, did not check closely) that a bear had stripped of bark some 15-20 feet above the ground.  This bear or group had stripped bark from at least 30 trees along a mile or so of logging road.  Many of those trees were totally stripped of bark all around the tree for a length of 20-30 feet, most of those starting at least ten feet above ground.



Back in the 50's and 60's, timber companies hired professional hunters to kill bears that were killing valuable trees.  The Olympic Penninsula went from having the highest bear population density in the world to having black bears almost exterminated.  They are finally coming back. 


   

[Todd Rahm]

That's kind of interesting. Never saw that in Alaska at all. Must be the kind of tree. Is black or grizzly, or both that do that in your area?

[Okanagan]

We just have black bears here.

Like you, I've puzzled about why so many black bears strip tree bark in this area, enough to get a legal extermination program going not all that long ago. 

Here's my latest theory:  It's all about nutrition.  Nutrition is harder to get for any animals in the endless rain and little sunlight of the Olympic rain forest.  So bears strip the bark from trees as a fairly easy to access source of food.  50 miles east of the true rain forest I've never seen where a bear has stripped a tree, and ditto for inland British Columbia.  It probably happens but is not common once out of the rain IME.

That carries over to elk and deer.  Pregnancy rate for Roosevelt cow elk is 50%.  For Rocky mountain elk it is 86%.  Apparently many Roosevelt cows don't get enough nutrition to carry a calf.     We've never killed a bull in the rain forest with enough fat on him to notice. Roosevelt elk in rain forest feed more hours per day than my experience with elk farther east. Again, they have to eat more volume to get enough food value from low nutrition forage.

Along that line, a dairy company man told me that alfalfa hay from this west side rainy area runs 6-9% protein.  East of our mountains in the desert region sun, irrigated alfalfa hay is 16% protein.  (From memory so exact number may be off but the concept is accurate and pretty close.)  So THAT'S why hay trucks constantly haul so much hay from E. WA state to the west side.

The first ever big bull elk we got in my immediate family was in a multi-year span of unusual dry sunny weather during spring and summer.  I think the nutrition was much better during the antler growing time those years.

So my guess is that the bears are going after the carbs and nutrition of inner tree bark because nutrition is so hard to come by in the rain forest.

[nastygunz]

I have never seen them do that here in the motherland.

[Hawks Feather]

Thanks for the post so that I could learn a little more. I remember seeing trees when I was a kid and visiting Canada that had strips of bark eaten as well. That was done by porcupines.

[Okanagan]

Thanks for the post so that I could learn a little more. I remember seeing trees when I was a kid and visiting Canada that had strips of bark eaten as well. That was done by porcupines.

Yep, porkies eat bark, gnawing on strips, especially near the top of the tree rather than stripping off big sections of bark like the bears do.  Moose eat poplar bark in wintering areas, and the tooth marks look a lot like the tooth marks in the first pic above, but they eat the outer bark along with the inner bark.  Pitw would be familiar with that.

In 1975 an old Indian lady on the coast told me that when she was a little girl they made candy from cedar bark.  The inner bark of a cedar probably tastes sweet to a bear.  Not sure about the fir.

 

[Hawks Feather]

Around here we tap maple trees for the sap and make all sorts of sweet things. I didn't appreciate maple items all that much when I was younger, but with age came an appreciation of that sweetness.

[nastygunz]

Cambium:


https://www.outdoorlife.com/blogs/survivalist/2011/11/survival-foods-can-you-really-eat-tree-bark/

[nastygunz]

"Inner tree bark can be obtained in large amounts year round, just by "skinning" a single tree, or by taking advantage of living limbs that have broken off during storms. The bark is relatively nutritious, packing about 500-600 calories to the pound, but it may be bitter tasting depending on the species and the tree's growing conditions. Most inner bark contains a surprising amount of digestible starches, some sugar, vitamins, minerals, and the bark also has tons of fiber, so brace yourself for a good internal scrubbing.

At least one Native tribe is well known for making bark an important part of their daily diet. There is a tribe in the mountains of upstate New York called the "Adirondack", and that name translates to "bark eaters" from the Iroquois language."

[FinsnFur]

Those are some big beavers

[Okanagan]

Those are some big beavers

[Okanagan]

In 1975 an old Indian lady on the coast told me that when she was a little girl they made candy from cedar bark.  The inner bark of a cedar probably tastes sweet to a bear.  Not sure about the fir.
 

After telling me about cedar bark candy, she added that when they got a store and could buy sugar, "Nobody eeever made cedar bark candy anymore."