Thanks for the comments. I did use the builtin flash as the light was getting a little dim (it was quarter to nine in the evening) and the shots needed pepping up. Also, as I was using the 35mm equivalent of 400 x 1.4 x 1.6 = 896mm and hand holding I really couldn't afford to let the shutter speed drop any lower.
Exif was 1/60 @ f/5.6(= f/8 with extender) and 800 ISO.
As for sneaking up and cropping, these are both full frame, uncropped and completely unedited shots. I agree the framing was a little off on the second shot but I did not have the luxury of taking my time as the bird was a little jittery - he appeared, I grabbed the shot, and he was off. The first bird was happily sitting there for several minutes, half dozing off, and I could have grabbed a hundred shots of him. I did get a few but I think the picture above is the best capture I got.
If I recall, for the first little guy I could not have got in any tighter as I was already at minimum focus distance. Actually, now I think about it, I may have had to back-pedal a little for the second shot too, which made the composition even more rushed. If he'd hung around I could have tried different framing, including portrait but I only got the one chance at a capture.
