As anglers, we have a fixation on rising fish, and understandably so. Those exhilarating moments, and the sustained anticipation that leads up to them, are part of what make dry fly fishing a favorite style for so many anglers. In the quest to find rising fish and identify the prevailing pattern, one of the clues that has traditionally been promoted is observing rise forms to help you identify what fish are feeding on. More recently, I’ve heard more people challenge this conventional wisdom, taking the stance rise forms are not particularly indicative of the type of insect that is being eaten, but instead are a product of a variety of other factors like current speed and water depth.
The argument for the insect camp goes something like this: depending on the type of insect and the stage of the hatch, trout will rise to them in different ways. For example, we often hear about the “caddis rise”, which refers to particularly splashy, acrobatic rises that allegedly come from trout chasing caddis as they emerge from the water, since they are fast emergers. We also hear about spinner rises, which are slow, subtle slurps since the dead adult mayflies are easy targets. We hear that tailing trout are an indicator of scuds and nymphs near the bottom of the streambed, and that a trout’s head emerging completely from the water is a sign that it is taking a high riding mayfly dun
The argument against is based on the idea that a trout rise is predicated far more on the environment and stretch of water than it is on the specific food source. In deep water runs, for example, trout must come up from substantial depth to rise for an insect. This rapid acceleration can lead to more explosive, water-clearing jumps that could be targeted at a wide variety of insects. A tailing trout, one would argue, is not necessarily feeding on a nymph (though it could be), but is instead just in shallow water, where any feeding that is done at a downward angle (sculpins, scuds, crayfish, etc) would result in its tail breaking the surface.
Personally, I take a stance that is somewhere in the middle. I think it would be naive to unequivocally say that because you’ve seen a couple of splashy rises, that the fish are feeding on caddis. They could be, but it could also be small trout prone to being a bit too aggressive, or a combination of depth and current speed that forces a fish to rise hard and fast. With that said, I think there is absolutely validity in using rises as a clue… as with anything in fly fishing, much of what is true and not true is dependent on the situation. If you’re seeing the same type of rise over and over again, and it’s in line with the prevailing hatch, then you can probably guess that the rise form is an accurate representation of what fish are feeding on. In one man’s opinion, rise forms are a piece in the puzzle, but not the whole picture. They have validity, but like anything, if you make all your bets on a one dimensional indicator, you might just be led astray.
What are your thoughts on rise forms? How much do they matter, or do they not at all?