Here the bird is banking away and you can see the extent of the white on the sides of the rump is not as extensive as that of Wilson's Storm-Petrel. I was able to relocate the bird later in the afternoon just as Jon Dunn arrived. At that time a second bird was located and Wilson's was discussed as to the flight style. Later the two were seen resting side by side and appeared identical in size. Wilson's should have been smaller at 7-1/4 inches compared to 9 inches for Band-rumped.
The next day, after 4 hours of scanning, I found the bird sleeping way out in the lake for Jan Shaw and Terry Whit. It took another 30-45 minutes to get the bird to fly for them. We all had big smiles after the long wait.