Hi Bob, these are hard to get good images of when they are in the trees owing to the profusion of high contrast branches, but easier if you can get them on the wing. It looks like you have an almost clear shot of the first one. Perhaps cropping in and toning down the background would give this subject a clearer view.
I believe this particular buzzard is also know as a Turkey Vulture http://en.wikipedia.org/wiki/Turkey_Vulture. They can be found from north the US/Canadian border all the way down to the whole of South America.
Yep, I'd agree with Frank. It looks like you've captured them very well, so I think they could both stand a fairly heavy crop and still come out okay.
The second one maybe just has too many twigs cutting across its body to be able to make a really good one out of it. But the first one has a good spread of tones and lot of detail in the feathers that could really be brought up.
You did well with these shots.
It is almost impossible to keep the bird properly exposed and not blow the highlights.
Thanks Frank, Donald and Bobo for your comments.