Upload & Sell: On
Welcome, Tom. Nice set!
I'm no expert, but some of what I've learned so far may be helpful.
I notice that you use aperture priority or shutter priority on your bird photos. That's fine for many uses, but animals present their own challenges. For instance, the sun shining off the Robin's back overexposes that. Sometimes that can be fixed in post-processing, sometimes not. When your animal has a range of colors (worst case, think panda bear or bald eagle, with white and black) that challenge gets greater. When taking a photo of a bird against the sky, you often will have to over-expose compared to what the metering says, since the part of the bird you're seeing is dark.
I take a variety of test shots to figure exposure. I also pretty much settle for ISO 800, and try to have a shutter speed no slower than 1/1250 sec. Then I adjust the aperture accordingly, and keep things set manually. I try to look at my results regularly, to see if any adjustment in necessary.
It's a challenging activity, but very rewarding; you already have some results with which you should be very happy, and it only gets better from here.