Yellow Crown Night Heron on Nest - Take TWO!!!

Went back today and re-shot the nesting Yellow Crowns. Waited until evening light. Found several active nests, here are a few:

http://canonbob.smugmug.com/photos/157197051-L.jpg

http://canonbob.smugmug.com/photos/157197689-L.jpg

This is the same nest I shot in harsh light the other day. Decided to use a fill flash here:
http://canonbob.smugmug.com/photos/157198705-L.jpg

This was the only one with chicks right now. I'll be following these throughout the next few months.
http://canonbob.smugmug.com/photos/157197465-L.jpg

Awesome shots yet again Bob.

I really like the first 2 shots of the same nest. They turned out great.

Question .. which flash do you use and how close do you have to get for effective range? I am in the market for a flash now and I definitely want something that will be effective when using a long lens. Th eon camera flash sucks lol.

I use the Canon 580 flash. I also use a "Better Beamer" attachment to focus it for longer FL lenses. I find I can get reasonable effect out to about 30 yards.