Hum the amount of UV in FL is not any different than other places of similar latitude, not sure if it affects plumage color, do you have a scientific reference for it? Species difference is a very plausible explanation
as for the color you are correct that if you fix the whites or more specifically the neutral grey the image will be color corrected in absolute sense however the sliver lining is that we usually want to keep some of the color cast to make it closer to what our eyes saw and closer to the original scene (natural), I wrote this article a while back on my blog to explain this issue
http://arihazeghiphotography.com/blo...n-photography/ have a look and see if it makes sense
for reference here is CA BO (juvi)
