Thank you for the comments, Neil (and Niels). These three photos were the 8th, 22nd and 23rd of the series. Each is (roughly) a 1600x1200 pixels segment of the original, thus the first shot is "smaller". Looking at the original of the second (= 22nd) photo, the peregrine is in the upper left corner - I was already "losing contact" with the central focus point. Here are two earlier photos, the 13th and the 19th, when I still had the focus point on the bird.
This forum has narrow limits for posting images. At dpreview files can be large and include the exif information. For gallery photos a 100% view is available. Perhaps I'll make another attempt to edit some of these more carefully (I fear I pushed the dark areas too much) and post at dpreview, linking here. Or would it be better not to edit much and just do NR in DxO?