Trout use shadows for concealment and for feeding, and it's a particularly important feature on small streams with large trout. Small trout can conceal themselves pretty much anywhere, but a big trout in a shallow river is "naked" in bright sunlight. In the broken light of the shadow line, it's much harder for predators like fly fishers, herons, and osprey, to see the trout.
Shade doesn't directly help a trout feed. There's no more food in the sun that there is in the shade. But a nervous, skittish trout in full sun is not likely feeding heavily. But the shadowy darkness created by trees, riverbanks, creates comfort zones where trout start looking up. Here are some tips for catching the big, wary trout in the shade.
Trout in the Shadows:
1. Use the shade to your own advantage. Don't approach from the sunny side, or cast in full sun if at all possible. You are more likely to be seen, and you casting motions and reflections from your line will spook trout if you stand in full sun and cast into the shade. If you must cast from full sunlight, get directly behind the trout in its "blind spot."
2. It's easier to see the trout and easier to see the fly if you are in the shade yourself because your eyes can adjust to the available light.
2. Use the shade to conceal your approach and get close. You want to be accurate as possible, so shorten the distance.
3. Crouch or kneel while casting to avoid being seen.
4. The trout itself often looks like a shadow—that's how they blend into and conceal themselves in shadow lines. Look for movement to distinguish the fish, you likely won't see a fish-shaped object. A feeding trout is a moving trout.