adjust bright lighting

Driving on a side road I spotted a Red-tailed hawk sitting on a post. I was so close that I stayed in my car. My lens was a fixed 600mm so I couldn't zoom out, making it impossible to photograph the whole body. I could tell that it was a first year hawk by the yellow eyes, plus the tail was barred brown & whitish. As they get older the eys will turn brown and the tail feathers will be red.