This male common loon was giving their alert call ( called a yodel) because another loon was circling the lake and considering landing. The males are very protective of their territory and try to reduce visitors, especially early in the breeding season. They often spin around in a circle as the intruder circles the lake, and I happened to be in a good spot to capture him.
D850. 600mm f/4 at f/5, 1/640 sec, ISO 1600. The loons back is out of focus but also covered by water as he spins, causing the distortion.
A significant crop because of the distance away, but the D850 file held up rather nicely I think.