Dunlins often raise one wing on their breeding grounds for either territorial or courtship reasons, but here it was simply retaining balance after a wave hit it on the side. It did keep the wing up for a good second or so as you can see from the wave having all but dissipated at this point. F/9 was a happy mistake as I had been creating portraits from point-blank range and forgot to open-up again, but it was great to get the whole wing in focus.
Canon 7DII + 500mm f/4 II + 1.4TC III, manual exposure, evaluative metering, 1/640s., f/9, ISO 800, natural light, handheld, added canvas above, eye work, toned down the brightest whites on the flanks (burn tool).