Some interesting behaviour by this Red-tailed Hawk that I've never seen before but I think it might be related to temperature regulation. I had just missed getting a shot of her leaving the water, where she was either drinking or bathing, but she flew quite close to me to dry off. Then she started repeatedly opening her mouth and ruffling her neck feathers in, what I believe, was a thermoregulatory response to the sudden increase in air temperature in our region. It was close to 20C (68F), a stark change from the recent sub-zero temperatures and, combined with the cooling dip/drink, it seems like a plausible explanation. You can see her cute little tongue in the second photo.