Not much help to you here....everyone knows that I am Squirrel biased, and have never seen a bad Squirrel shot...as long as they are alive!
With Squirrels, you often get what you can, they aren't still for long,unless they are paid models like I use. If you like Squirrels, you can get your fill of them here
Flickr: Festus 2009's Photostream
Some very fine shots in the mix.....it takes a little practice and learning to anticipate their movements, but it is great fun, and if you learn to shoot Squirrels it will enhance your other shooting abilities. Hasn't helped mine a lot, but I can shoot Squirrels!
Yard Squirrels Photo Gallery by James Williams at pbase.com
Best Regards& I enjoyed the Squirrel shots!