Came across this Pied-billed Grebe at Sweetwater Marsh in Tucson, Arizona. It was paddling around and caught a frog which was very big and the bird spent the next 15 minutes trying to choke it down which it eventually did. Camera was a Canon 5D Mk III with a Canon 500mm f4 lens on a tripod. Settings as follows. Aperture was 5.6, speed was 1/1250 sec and ISO was at 800.