Welcome to the Kentucky Native Plant and Wildlife Blog.

Welcome to the Kentucky Native Plant and Wildlife Blog.
The purpose of this blog is to provide information on using native plants in the landscape, issues related to invasive exotic plants, urban wildlife management, and wildlife damage management. It is my intention that this information will assist you in deciphering the multitude of information circulating around the web and condense in some meaningful method as it relates to Kentucky. In addition, I hope to highlight a native plant that can be used in the landscape.



Wednesday, September 7, 2011

Why do squirrels strip bark and chew on small branches?




This time of the year is about when I start getting calls about gray squirrels stripping the bark off trees or chewing off small branches and letting them drop to the ground.  This seems to be particularly true in urban areas with pin oak trees and I usually see it as I pass by one large pin oak next to Haggin Hall on my way to work.   The question often asked is why?  No one knows for sure but there are some theories out there and my favorite one is because squirrels are neurotic little creatures and they simply like to do it.  Squirrels are kind a crazy animals and have lots of quirky behaviors such as making loud noises during sexual intercourse, which of course has nothing to do with reproduction or anything else, it just appears they like to do it and it could be that stripping bark and clipping small branches is fun and they like to do it or it could help keep those shiny bright teeth good and sharp.  Another theory is that since this occurs close to the time when females are giving birth (in the spring and fall), and giving birth is evidently no picnic and can be quite painful in squirrels, and because they exhibit different behaviors during pregnancy like not eating before giving birth, this behavior is a response to the pain associated with giving birth.  The final theory has to do with finding high quality food or material for nests and of course the cambium layer is rich in nutrients both in the spring and fall and by stripping bark they are getting essential nutrients, or perhaps, it just tastes good and the bark provides good building material for their nest.  In most cases the damage caused will not kill the tree but it could potentially damage it if some other pathogen found its way into the wound, although this generally doesn’t kill the tree either.  If you really feel like you must control this type of behavior, the best solution is to temporarily wrap the areas with flashing to prevent further damage or to use one of the many taste repellents, like hot sauce, to deter them long enough for the behavior to cease and desist. Or perhaps you can get some simply enjoyment by watching these large tree climbing rodents carrying out their crazy behavior.

21 comments:

  1. AnonymousJune 08, 2012

    My husband thought I was crazy when I said the squirrels were chewing our trees. My question now is the limbs that are falling are a pretty good size, I wouldn't want one to fall on me! I'm sure it wouldn't hurt me but it would scare the heck out of me. So are the squirrels to blame for the falling tree branches?

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  2. If the limbs are big and falling, it probably is not from squirrels. Squirrels primarily chew on small branches, not large ones. I would have a certified arborist visit to look at the limbs on the tree to see if they are problems. Also, look at the ends of the branches being clipped. If it is squirrels the cuts will be at a 45 degree angle and look like someone took a knife to cut them, very smooth.

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  3. We have a Japanese Maple that is getting tormented like crazy. We are having small branches being chewed off daily. Afraid they are going to ruin the tree at this point. The branches do look like they are being chewed. There are small teeth marks. We have a large squirrel population. We do see them running through the tree but we are not seeing them up there hanging out. These are not 45 degree cuts and they do not look like a knife cut however when we break the twig, we get splintering, which these do no have at the break. We have a lot of bird feeders and lately have put up squirrel barriers as they were eating way too much. Is this squirrel damage? What to do? This s a large tree, lots of branches. Flashing and hot sauce not an option...

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  4. This is undoubtedly done by squirrels even though you do not see them up in the branches. You have several options, one is to get some traps and begin to remove individuals from the population (ie reduce the population in size) but of a more immediate concern you might want to get a repellent with the active ingredient thiram (chew not) and spray it on the branches to keep them from chewing on them. Otherwise, the only option would be to try to use a covering of hardware cloth that they could not chew through and that would be very, very expensive.

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  5. January, 2013 in Wisconsin....saw this morning a gray squirrel chewing off the bark on various 3-6 inch diameter branches of a soft maple tree. It has damaged branches on other trees which I first noticed 20-30 days ago on my 3 acre lot. The squirrel is not doing it for food as the shavings are all flying in the air easily noticed on top of the snow. I also have many mature oak trees with a bumper crop of acorns this past year. The squirrel disappeared after going for my shot gun.

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    1. Boy! I hope you keep your shot gun locked up so the squirrel can't get at it!

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  6. They are most likely clipping the branches for their nests in the trees.

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  7. Haha I have a funny thought about them being interested in selling landscape barks too! :p

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  8. AnonymousMay 05, 2013

    buckwheat may in wisconsin squirrels stripped off all bark on maple trees killed both trees they did not take bark for nest kind of funny to see them slide down tree because nothing to hold on to

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  9. I just picked up 50 or more small branches from my front yard, some 1/2 inch in diameter but most smaller, most about 1 to 2 feet long. Enough to fill two large garbage containers.
    I have not seen squirrels up there chewing, but do see where the branches are coming from. About 60-70 feet up, from the tops of old cottonwoods. Spray you say?? By plane maybe.
    It really doesn't appear the branches have been chewed on--just cut, and none of the bark is missing. I'm going with the theory that they do it . . . just because they can and they enjoy watching me work! If they really wanted the branches for their nests, then it's way past time for them to come down to the ground and pick them up! Moreover, they must be planning for 20 or 30 nests based on the number of branches.

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  10. I would venture a guess that this is not squirrel activity because squirrels are not typically fond of cottonwoods. If it is squirrel activity you would notice the branches appear to have been cut by a knife, with a very clean 45 degree angle slice. I suspect this is due to some type of insect chewing on branches but not being an entomologist, I would not want to say for sure. There is a horticulture specialist at North Dakota State University that deals specifically with cottonwood tree issues and perhaps you could contact him.

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  11. I walked out my back door this morning and found a branch about 20 feet long and at least three inches round had fallen and standing straight up about a foot from tree. It had been well chewed could this have been a squirrel or perhaps something else in the squirrel family? I did notice earlier in weeks some wood chip on ground around the tree.

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  12. Consider something like a porcupine. They are a well known forest pest.... We also saw a raccoon chewing on limbs. Must be something bigger than a squirrel. Do Opossums chew trees too?

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  13. Porcupines will indeed clip branches however they do not occur in our region of the country. They are also usually not found in urban environments. Opossums should not be a culprit because they do not have the teeth to chew like this.

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  14. I've lived in this house 40+ years and have never seen anything like the piles of chewed-up pin oak branches in my yard. My neighbors also have pin oak trees, but they seem to have almost no branches in their yards. The acorn crop is also extra large this year. The branches all seem to be from about 8 to 12 inches long. Is there some edible part at that point on the branch? Just puzzling.

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  15. I just watched a squirrel in action in my back yard. I'm so sorry I did not have my phone to take video. She tore off long strips, then climbed higher to continue this while hanging upside down. It did appear she carried a very small strip of the bark off with her. But She bit off way more than she could chew..lol

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  16. I've noticed in my backyard also. There has been a foot of snow outside for days, is it possible they can't get to their buried nut reserves and this is source of food?

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  17. The most definitely will use the branches and stems or twigs for food as they can extract nutrients from the cambium layer, just inside the bark.

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  18. Something has started eating the bark around my apple trees. pear trees even trying my walnut tree.....what animal could this be ...not sure if its the same animal but some of my trees have branches chopped r chewed down then the bark stripped off....I am sick my 10 year old apple tree bark was stripped completely around the bottom......I don't think I'll save it...How can I stop this......this is the first year this has happened........

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  19. Sure hope I can find out what to do.......Thanks

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  20. This is most likely due to cottontail rabbits (depending on where you live). The bark of fruit trees is highly attractive (particularly during hard winters) because of the high sugar or carbohydrate content. They can most certainly girdle a tree and kill it and the solution lies in either using hardware cloth to keep them away or a repellent of some sorts, of which there are numerous ones on the market. Also look below the snow line to see if voles have been eating on the roots and girdling them as well.

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