Sadly, it only took the squirrels a day to breach my defenses. A double assault occurred on my 'black sunflower' feeder this morning. The assault came from the ground and air. The squirrels managed to climb to a far branch and sit on the branch as it succumbed to their weight, leaving just a small leap to the safety of my feeder. I propelled that assault by trimming the tree. The ground assault occurred prior to the air (not good combat tactics), as they crawled up the pipe. Momentarily I also propelled this attack as I got out WD40 and sprayed the pole. For a while, they would attempt to shimmy up the pole, slipping further than they gained. But now...they have figured it out. I think they are using some sort of special pads connected to their feet. Not sure.
I have some 'work' work to accomplish but later today I am going to Home Depot and will buy some 5" PFC pipe. As I recall, I think it was Charlie who said that squirrels can't get a hold on that large diameter pipe.