Ed - Glad you noticed the unusually small aperture used on the image. I had been using the 2.0x + 1.4x TCs stacked to get some distant shots of Spoonbills. (I use apertures of f/11-f/16 when shooting with stacked TCs for image clarity.) I had just removed the 2.0x TC but left on the 1.4x when I saw the egret land and so I took the shot without re-adjusting the fstop. As it was very bright at the time the smaller aperture worked quite nicely in Aperture-Priority mode, yielding a shutter speed of 1/800s, more than fast enough for a perched bird! The background was far enough back that it did not significantly affect the shot.
Discussion
5 replies40D, 700mm, f/13, 1/800s, ISO 400, cropped to vertical.
Curious why you used f/13?