This was shot late in the day. The preserve is in a valley so light doesn't last very long there. My first time trying to shoot at ISO 3200, not too bad. Flight shots are definitely easier without the teleconverter.

This image really demonstrates the Mark III's ability in low light situations. The EXIF below is wrong in the time of day - I had forgotten to set the camera clock back from Minnesota time. It's actually about 3:30 in the afternoon.