Great shot of the Egret. When I shoot these white birds I use spot metering which should generally give you the proper exposure. I can adjust the (RAW) exposure in post processing if/when it does overexpose.
Tried out some close-ups with my new 6d, 50mm lens and 430EX flash. Interestingly the 6d doesn't have a built-in flash. And there is no white balance button...that I've found yet. But I love the colors I've gotten so far.