Spent half the day yesterday enjoying temps in the mid-80s (on March 18th!) by fishing my favorite sucker creek. Watched gangs of whites in full spawning racing stripes, but couldn't get a bite. Saw hogsuckers, but couldn't get bait or flies to their spot at the top of a waterfall where they hide under a ledge with the water rushing over them.
Moved to a different location a few miles downstream where I could see tons of redhorse (all or mostly shortheads) and quillbacks feeding and relaxing. Spent hours trying to get them to bite before finally connecting witht the biggest shorthead I've ever seen. My two hands couldn barely touch around its girth, and it was long and heavy. Couldn't find tape measure or scale in my bag!
Anyway... The water was ultra clear and only 1/2-2 feet deep. I watched the quills and shortheads for hours from a hiding place only a few feet away. Both were doing what I've previously seen quillbacks do: tipping to the side almost 90 degrees, light flashing off the upturned side. Never really thought about why they would do it. Thought it was some quirk of quillback feeding behavior and was thankful as it's been a way to find quillbacks when I couldn't actually see them: the flashes of silver told me where they were and what they were doing. Didn't help me catch them, but still a cool indicator.
Last night the shortheads and quills were both doing it. A lot. And watching them from so close up, it looked to me like they were trying to get a better look at something on the bottom, either looking for food or checking to see if something actually was food.
Curious if this is a thing everyone sees all the time, what other theories or definitively established reasons there are to explain it, and what others think it tells us about tactics we could use to exploit it (assuming it is sucker-specific sight-feeding).
I'm going to try to get some video underwater next time to see what they're doing immediately before and after tipping. Probably won't work, but worth a try.