I am guessing that the squirrel is not likely to starve over the winter months
Its a shame that its feet are not visible and the surroundings suggest it is in captivity rather than its natural environment. Whenever photographing wildlife try to adjust your angles and DOF to imply natural surroundings.
The second shot also suffers from this problem but your focus is spot on around its eyes. The colour is very rich and almost looks a little too saturated. I know that you are struggling currently with colour profiles though, so hopefully after you have that sorted it will be fine.
Third shot has nice focus, exposure, crop and DOF but the one visible eye lets this shot down slightly. This is the problem I always have with wildlife, unlike landscapes or architecture, wildlife has a habit of not looking in the right direction or doing as we would like.
The little critter at the end, the second pose is great and shows a lot of character. If I had taken these shots I would have only displayed the second of the two as the first reduces its impact. The focus seems very slightly off though and its not pin sharp around the eye as is the usual aim with wildlife. This could be due to the reduced size of the pictures for display on the web or it may be like that on the original, either way a little selective USM applied to that area will improve this shot.
The latest owl addition is far better. It looks like it could be in the wild, you have both eyes in shot and have used correct DOF to isolate the bird from its surroundings. On my monitor the picture is very slightly blown out on the front of the bird but nothing major. Overall this a great shot that I would be proud to have taken.
For your first outing with all new equipment, I would be pleased with the results you have gained. Its very difficult to change to new equipment and adjusting takes longer than most people would expect.