This small Burr Oak had a substantial drop of twigs this past week. It had to have happended over a 1-2 day period, and the only thing I can think of is squirrels. The tree is only about 20' tall and poorly branched, but looks to have a heavy crop of acorns. Thoughts??
There are insects known as twig girdlers. While I don't know specifically that they infest Bur Oak in western Wisconsin, I think that is a plausible explanation.
Why would you think squirrels?
I speculated squirrels for two reasons: the twig drop occurred over such a short period of time and the heavy acorn crop on this tree. Plus, Q. macrocarpa acorns are so much larger (and better tasting) compared to Q. ellipsoidalis, which is the other oak we have in large numbers. Perhaps I'm giving them too much credit, but my thought was this would be a highly efficient means to get the acorns on the ground quickly, rather than waiting for them to fall sporadically. The squirrels around here are very bright and ambitious. ;)
Anthropomorphism at its best!
Like they could be your children...
Examine the ends of those dropped twigs where they were formerly attached to the tree - and on the remaining tree branch. This should reveal a wealth of information from which you might determine a cause to this effect. Share such imagery with the audience here - we all want to know.
http://lancaster.unl.edu/hort/articles/2013/TwigGirdler.shtml
I really don't think squirrels are capable of such organization of labor-saving crop gathering. If I had to hazard any further possibilities - remote at that - I would say if every broken off twig was lustily laden with substantial seed - amazonian acorns - then maybe you had some inclement weather which wind-whipped these small branches from the tree, aided by the unusual extra weight of maturing acorns.
A great text for all: Insects that Feed on Trees and Shrubs by Warren T. Johnson and Howard H. Lyon. Originally penned in 1976, I've been dog-earing pages of my second edition since it was printed in 1988. It may have been updated since then. Take a look at page 264, where the writings about Twig Pruners and Twig Girdlers begins. Excellent information on this subject and insect life cycles is succinctly presented.
I am adding that book to my envelope stuck on my bulletin board (titled "Books to get"), for an internet used book shopping expedition to be done in the dead of winter. Now I am getting interested in pests too, due to my recent sawfly problem and this interesting thread. Maybe it was aliens landing in your tree. You should look around, it could be a new kind of "crop circle". I think you are too far east for "Sasquatch".
Could be a disjunct population - like my family from Wisconsin - that were poor temperate rainforest residents, and were sent to live on the prairie...
The squirrels have been behaving a bit odd lately. Last week I watched one eating what appeared to be a mushroom, and this morning I watched one carry off what also appeared to be a mushroom. We've had plenty of moisture this season, and there are some strange looking fungi popping up. Next thing you know they'll be breaking into the garage and stealing my tools.
Very interesting about twig pruners and twig girdlers. I suppose the big question is whether on balance they cause any significant harm vs. fitting into the ecology in a way that is "beneficial."
Rosemary, that's a good point. Here's a photo of a larger twig I plucked off the ground. Looks like it may have been chewed, but I'm really not sure about this.
Hmmm. I tend to agree, but how do you know it isn't a fungal disease from the photo?
I'd like to give you a long explanation about how I did a thorough analysis under a microscope, but the truth is I'm speculating about squirrel damage. Why do you agree with me?
Because the areas of damage appear to be localized to the area where it broke and I do not see any cancers or lesions elsewhere. I can't say whether it isn't insects, though, so I'm not endorsing the squirrel idea.
I've posted these pictures on another site haunted by oakophiles, and there's a consensus that squirrels are to blame, but no one seems to be certain about this. I'm not sure innocent until proven guilty applies here, but the squirrels aren't talking and I'm declaring them mammals of interest.
Hmmm, I did the briefest of google searches. Interesting photos of twigs cut by the twig girdler. Does not look like your raggedy end at all, the girdlers make a perfectly neat circumferential cut, and when it falls there is only a central core that is raggedy. Here is a link.
http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note96/note96.html
I think I may have found the smoking gun...
I just took a walk and found this evidence laying about, with all three twigs found in a mulched mixed shrub border some distance from the tree in question. If not squirrels, then what?
Lol Pseudo, you have intellectually superior squirrels in Eau Claire...
super squirrels.
But, Mr. Squirrel may have just happened upon the fallen twig, and dragged them over to the shelter of the shrub border to get the nut out. I think you should get a 'Squirrel cam' and we can take turns watching.
Pseudo needs to do the real thing - not the pseudo-science.
Cut some of those twigs length-wise already, and see if there has been any tunneling around inside the twig.
While the squirrel cam is an intriguing idea, I think it's too labor intensive. What if one of the investigators on cam duty would zone out for an instant? I think the question can be readily answered with a simple DNA analysis which will surely distinguish twig girdler saliva from squirrel saliva.
Hey, pseudo-science is my pspecialty. I'm very good at linking completely unrelated events and then drawing conclusions based soley on my life experiences, beliefs, and opinions. It's the American way, dammit!
I think the "squirrel cam" is a great idea. My son-in-law put one up on our farm property and it was pretty amazing to see what goes on in a woods when humans are not around.
I'm blushing, except you said that was when humans aren't around.
A friend of mine used a raccoon-cam to catch the suspects in the act. He assumed it was raccoons but couldn't figure out how they could reach the bird feeder. Once he saw their modus operandi, he was able to formulate a better defense. Frankly, I don't recall who won in the end, him or the masked bandits.
Y'all crack me up.
